This study evaluates headspace gas chromatography–ion mobility spectrometry (HS-GC-IMS) for characterizing the volatile profiles of five Origanum species and detecting blends with nonoregano leaves. MS-supported compound identification revealed species-specific differences, particularly in carvacrol/thymol and sesquiterpene profiles, while the method showed good repeatability and stable profiles over six weeks.Authenticity experiments using oregano blended with marjoram, myrtle, thyme, olive, and hoary rock-rose showed that potential marker compounds could be identified for marjoram and myrtle. The results demonstrate that HS-GC-IMS offers a sensitive and cost-effective approach for Origanum characterization and selected oregano adulteration screening.<blockquote><h4>The original article</h4><h4><a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/afsthl/article/doi/10.1021/acsfoodscitech.6c00607/5428045/Gas-Chromatography-Ion-Mobility-Spectrometry-for">Gas Chromatography-Ion Mobility Spectrometry for Characterizing Different Species of Origanum and Detecting Blends of Its Products</a></h4>Modestus Wigger* ; Phil Carbow; Daria Garder; Silke Hillebrand; Ursula Telgheder; Stefanie Sielemann*ACS Food Sci. Technol. (2026)&nbsp;<div><a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1021/acsfoodscitech.6c00607">https://doi.org/10.1021/acsfoodscitech.6c00607</a></div><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/">CC-BY 4.0</a></h6></blockquote>Selected sections from the article follow. Formats and hyperlinks were adapted from the original.<div><div><div><div><div><div><div>Gas chromatography-ion mobility spectrometry (GC-IMS) has emerged as a complementary technique to GC-MS for food-aroma analysis and offers several advantages for aroma profile characterization. Applications include the authentication of olive oils, (<a href="javascript:;">14</a>) monofloral honeys, (<a href="javascript:;">15</a>) and many more. (<a href="javascript:;">16</a>)</div><div>Many GC-IMS approaches in food analysis use HS sampling. (<a href="javascript:;">16</a>) It eliminates the need for sample preparation and is optimal for transferring the compounds of interest into the GC system. After GC separation, IMS provides an additional dimension via drift time. Furthermore, it is a very sensitive, less costly method compared to a conventional quadrupole MS. Unfortunately, the capabilities for identifying compounds in IMS are limited, as it lacks the powerful databases that MS have. Therefore, in the analytical setup used, a quadrupole MS is installed on a separate flow line, as described by Budzyńska et al. (<a href="javascript:;">17</a>) and Augustini et al. (<a href="javascript:;">18</a>) Coupled with the NIST MS database and the peak-assignment approach of Augustini et al., (<a href="javascript:;">18</a>) this method enables reliable identification of most GC-IMS signals. Using this HS-GC-MS/-IMS configuration, it is demonstrated how GC-IMS can characterize Origanum volatilomes by analyzing five (sub)species, including one species represented by material from two geographic origins. To minimize environmental effects on volatile expression, reference seeds were grown under identical conditions in an indoor greenhouse prior to analysis. This approach helps to compare chemotypic differences among taxa and origins under controlled growth conditions.</div><div>Beyond chemotaxonomy and quality control, a further motivation for robust analytical fingerprinting of Origanum is the widespread issue of oregano adulteration. According to the European Spice Association, only the leaf product derived from Origanum vulgare ssp. hirtum and Origanum onites may be called oregano, while the International Organization for Standardization defines oregano in ISO 7925:1999–10 as leaves from the genus Origanum except Origanum majorana. ISO also specifies that the proportion of stalks and other plant parts shall not exceed 3% and that extraneous matter shall not exceed 1%, a requirement often violated in commercial oregano for economic reasons. Maquet et al. (<a href="javascript:;">19</a>) reported that 48% of oregano samples collected across the supply chain in the European Union were adulterated. Common adulterants include leaves from Cistus spp. for a dark green color, from olive (Olea europaea), and myrtle (Myrtus communis) for financial reasons. Another possibility could be an accidental admixture with other herbs, such as marjoram (O. majorana) or thyme (Thymus spp.). (<a href="javascript:;">20</a>) These types of food fraud are challenging for consumers and regulatory authorities to identify. One possibility is to analyze leaf material macroscopically or microscopically for foreign matter. (<a href="javascript:;">21</a>) However, a variety of analytical approaches have been developed to detect oregano adulteration. Fourier-transform infrared (FT-IR) spectroscopy has been used to screen for olive, myrtle, sumac, hoary rock-rose, and hazelnut leaf adulterants. (<a href="javascript:;">22</a>) Flügge et al. (<a href="javascript:;">23</a>) combined next-generation sequencing (NGS) with nuclear magnetic resonance (NMR) spectroscopy to detect olive, myrtle, hazelnut, and pink rock-rose (Cistus) leaves. Liquid chromatography–mass spectrometry (LC-MS) targeting oleuropein has been developed specifically to identify olive leaf adulteration (<a href="javascript:;">24</a>) and is also used by Maquet et al. (<a href="javascript:;">19</a>) as an analytical method for an EU-wide control of adulteration. Rocomora-Rivera et al. (<a href="javascript:;">25</a>) were the first to apply GC-IMS for the detection of oregano adulteration. Using orthogonal partial least-squares discriminant analysis (OPLS-DA), they identified admixtures containing olive leaves, but they did not test other potential adulterants. They also applied the method to commercially available oregano samples. However, their results were not verified by other analytical techniques. In the presented study, the feasibility of GC-IMS for detecting common adulterants in oregano, namely the leaves of hoary rock-rose, olive, myrtle, thyme, and marjoram, is tested by identifying marker compounds. Because only one authentic oregano type and no commercially adulterated samples were available, blends were prepared by combining oregano with candidate adulterant leaf material to simulate adulteration scenarios.</div><div>The objectives of this study are to evaluate HS-GC-IMS for volatilome profiling of five Origanum (sub)species grown under controlled conditions and assess the technique’s ability to detect common leaf adulterants in oregano blends.</div><h4>2. Material and Methods</h4><h5>2.3. Analysis</h5><div>An <a target="_blank" rel="noopener noreferrer" href="https://labrulez.com/en-us/gcms/library?mainauthorItems=1&amp;search=AOC5000">AOC5000</a> (Shimadzu Corporation, Kyoto, Japan) HS sampler incubating for 30 min at 120 °C was used for the static HS analysis of the samples. 500 μL of the HS was injected into a <a target="_blank" rel="noopener noreferrer" href="https://labrulez.com/en-us/gcms/library?mainauthorItems=1&amp;search=2010">GC 2010-Plus</a> (Shimadzu Corporation), equipped with two split injectors with a split of 1:20 and two identical analytical columns (HP-5 MS UI 30 m × 0.25 mm × 0.5 μm; Agilent, Santa Clara, CA, USA), each leading to one spectrometer (IMS or MS). A constant flow rate (35 cm/s) of helium 5.0 (Messer Industriegase, Siegen, Germany) was used. The GC temperature program started at 40 °C, held for 4 min, then heated with 3 °C/min to 150 °C, then heated 10 °C/min to 220 °C, held for 12.33 min, for a total program time of 60 min.</div><div>One analytical column was connected to the quadrupole MS QP-2010 Ultra (Shimadzu Corporation) in scan mode (m/z 32–300 at 3.3 Hz) with electron ionization (70 eV) and the other to the ion mobility spectrometer (G.A.S. Gesellschaft für analytische Sensorsysteme mbH, Dortmund, Germany). The drift tube (dimensions: 15.2 mm × 53 mm; temperature: 80 °C) was flushed with 75 mL/min drift gas (nitrogen 5.0, produced by an in-house generator), and ionization was performed by atmospheric-pressure chemical ionization with a 3H source. The field strength was 500 V/cm.<h4>3. Results and Discussion</h4><h5>3.1. Identification of Volatiles in Origanum</h5><div>For the characterization of the volatilome of different Origanum species, it is necessary not only to detect compounds sensitively using HS-GC-IMS but also to identify them. For identification, HS-GC-MS was used in addition to HS-GC-IMS. The HS-GC-MS enables identification of unknowns through database comparison of fragmentation patterns.</div><div><a href="javascript:;">Figure 1</a> shows the total ion current (TIC) chromatograms for both HS-GC-IMS and HS-GC-MS of a fresh leaf from O. vulgare ssp. hirtum, with retention time on the x-axis, the integrated ion current for the IMS, and the intensity for MS on the y-axis. The y-axis of the HS-GC-MS chromatogram is logarithmically scaled, because it shows significant intensity differences (3 orders of magnitude between baseline and the highest peak), and linear scaling would discriminate small peaks in visualization. Most analytes are properly separated within the 60 min analysis time. When comparing the signals in both chromatograms, it is noticeable that they are shifted by several minutes. For example, an analyte (marked with an arrow), eluting at 35.8 min in the IMS flow line, elutes at 27.6 min in the MS flow line. However, the shift in retention times does not allow direct peak assignment. Using the 2-alkanone standard mixture as a reference, the retention times can be converted to retention indices using <a href="javascript:;">eqs 1</a> and <a href="javascript:;">2</a>, which can then be used to derive retention times for the GC-MS. An example calculation is provided in the <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/afsthl/article-supplement/5428045/pdf/fs6c00607_si_001/">Supporting Information</a>. To demonstrate the effectiveness of this method, the TIC chromatograms shown in <a href="javascript:;">Figure 1</a> are replotted in <a href="javascript:;">Figure 2</a>, with the calculated retention index on the x-axis instead of the retention time. The marked substance in <a href="javascript:;">Figure 1</a> is visible at a retention index of 992 in the HS-GC-IMS and 986 in the HS-GC-MS, corresponding to a deviation of only 6 RI units (≈0.6%), indicating very good assignment between the two methods. It is noticeable that, due to the logarithmic scaling of the intensity in the HS-GC-MS chromatogram, the peak pattern resembles that of the HS-GC-IMS. The IMS exhibits a nonlinear response over the measured intensity range. Therefore, logarithmic scaling of the MS signal intensity provides a representation that more closely matches the response characteristics of the IMS. Although the retention index still shows a slight shift, peak assignments are possible by comparing peak patterns. Additionally, within the retention index range of 600 to 700 (highlighted in gray), it is noticeable that the HS-GC-IMS exhibits more intense peaks than the HS-GC-MS. Peaks with a retention index above 700 become broader in the HS-GC-IMS, which can be explained by a less heated transfer and detector setup. Regarding sensitivity and separation power, the HS-GC-IMS is therefore more suitable for higher volatiles, while the HS-GC-MS is more suitable for lower volatiles, as it is also shown in Schanzmann et al. (<a href="javascript:;">33</a>) The results show that the IMS has comparable analytical power to the MS, but is more cost-effective, as it requires no vacuum and less maintenance.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ACS_Food_Sci_Technol_2026_Figure_1_Total_ion_current_TIC_chromatogram_of_a_leaf_from_O_vulgare_ssp_hirtum_cover_fc6d9adaee.jpg" alt="ACS Food Sci. Technol. (2026): Figure 1. Total ion current (TIC) chromatogram of a leaf from O. vulgare ssp. hirtum measured by headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) (upper part) and HS-GC mass spectrometry (HS-GC-MS) (lower part). The intensity of the HS-GC-MS-TIC is given on a log10 scale for better visualization, since the intensity range is 3 orders of magnitude and small peaks would not be visible in linear scaling." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ACS_Food_Sci_Technol_2026_Figure_1_Total_ion_current_TIC_chromatogram_of_a_leaf_from_O_vulgare_ssp_hirtum_cover_fc6d9adaee.jpg 201w," sizes="100vw" width="1600" height="1247"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ACS_Food_Sci_Technol_2026_Figure_2_Total_ion_current_TIC_chromatogram_of_a_leaf_from_O_vulgare_ssp_hirtum_bb33b1d86a.png" alt="ACS Food Sci. Technol. (2026): Figure 2. Total ion current (TIC) chromatogram of a leaf from O. vulgare ssp. hirtum measured by headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) (upper part) and HS-GC mass spectrometry (HS-GC-MS) (lower part) with the calculated retention index based on 2-alkanones on the x-axis. The intensity of the HS-GC-MS-TIC is given on a log10 scale for better visualization, since the intensity range is 3 orders of magnitude and small peaks would not be visible in linear scaling." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ACS_Food_Sci_Technol_2026_Figure_2_Total_ion_current_TIC_chromatogram_of_a_leaf_from_O_vulgare_ssp_hirtum_bb33b1d86a.png 201w," sizes="100vw" width="2508" height="1946"></div><h5>3.4. Comparison of the Species</h5>The first main topic of this study is to investigate species-specific variations in the volatilome. The HS-GC-IMS chromatograms for each species are illustrated in <a href="javascript:;">Figure 6</a>, where all Origanum species can be compared visually. Distinct differences in peak pattern and intensity between the samples are evident.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ACS_Food_Sci_Technol_2026_Figure_6_Headspace_gas_chromatography_ion_mobility_spectrometry_HS_GC_IMS_chromatograms_962a045868.png" alt="ACS Food Sci. Technol. (2026): Figure 6. Headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) chromatograms of five different species, one from two origins, Germany (DE) and Greece (GR), with the drift time on a reactant ion peak (RIP) relative scale (RIP position: ∼4.9 ms), the retention time in seconds on the y-axis, and the intensity in V on a color scale." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ACS_Food_Sci_Technol_2026_Figure_6_Headspace_gas_chromatography_ion_mobility_spectrometry_HS_GC_IMS_chromatograms_962a045868.png 152w," sizes="100vw" width="1254" height="1289">It can be seen that the species O. vulgare ssp. hirtum contains more monoterpenes/monoterpenoids, especially carvacrol, than O. vulgare ssp. vulgare, which shows higher amounts of sesquiterpenes. This comparison provides insight into the profile of each species, as even two different plants of the same species can exhibit distinct profiles.<h5>3.5. Detection of Blends in Oregano</h5>After investigating the volatilomes of different Origanum species, the potential of this technique to detect food fraud can be demonstrated by comparing the volatilomes of oregano and its adulterants. The capabilities and limitations of GC-IMS for identifying oregano adulteration were assessed within this feasibility study by using self-made blends, as no intentionally fraudulent samples were available. For this purpose, common adulterants for oregano, namely leaves from olive, thyme, marjoram, myrtle, and hoary rock-rose, were added in different mass ratios (10%, 30%, and 50%) to ground oregano known to be pure and from O. vulgare ssp. hirtum. The sample material is shown in <a href="javascript:;">Figure 9</a> as a photograph.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ACS_Food_Sci_Technol_2026_Figure_9_Photograph_of_the_sample_material_80493b7a68.png" alt="ACS Food Sci. Technol. (2026): Figure 9. Photograph of the sample material: Oregano (O. vulgare ssp. hirtum), olive (O. europaea L.), thyme (Thymus vulgaris L.), marjoram (O. majorana L.), myrtle (M. communis L.), hoary rock-rose (C. incanus L.)." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ACS_Food_Sci_Technol_2026_Figure_9_Photograph_of_the_sample_material_80493b7a68.png 245w," sizes="100vw" width="1254" height="291"><div>These pure samples were analyzed by HS-GC-IMS, and the chromatograms in the <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/afsthl/article-supplement/5428045/pdf/fs6c00607_si_001/">Supporting Information</a> generally show lower numbers and lower intensities of volatiles in olive leaves and hoary rock-rose than in oregano. In contrast to oregano, the volatilome of thyme and marjoram is comparably complex, with thyme exhibiting a very similar pattern with high proportions of thymol/carvacrol and a variety of monoterpenes and sesquiterpenes. Marjoram also contains many monoterpenes and some sesquiterpenes, but no carvacrol/thymol. The chromatogram of myrtle shows some monoterpenes, but not in the same numbers and intensity as oregano.</div><div>Potential marker substances were identified by analyzing all individual signals in the blending material and excluding those present in dried oregano or the fresh leaves of the different Origanum plants. Additional GC-MS measurements, the previously described peak assignment, and the NIST database enabled tentative identifications.</div><div>In marjoram piperityl acetate (RI = 1305, DT = 6.15 ms) is found, which has been tentatively identified by the described procedure. The peak intensity has a coefficient of variation of 29.9% for the lowest blend (10% marjoram in oregano) in technical triplicate. The high variation can be explained by coelution of the peak with the dominant carvacrol. The limit of detection (LOD) for marjoram in oregano using piperityl acetate as the marker was estimated at 4.1% based on the signal-to-noise (S/N) approach of Schanzmann et al. (<a href="javascript:;">33</a>) The S/N was determined for the 10% blend, and the blend ratio corresponding to S/N = 3 was calculated assuming proportionality between signal intensity and blend level. Creydt et al. identified blumeatin as a marker for marjoram adulterations using liquid chromatography–mass spectrometry and established a LOD of approximately 5%. (<a href="javascript:;">41</a>) Consequently, both volatile and nonvolatile analytes yielded comparable detection limits.</div></div></div></div></div></div></div></div>

Gas Chromatography-Ion Mobility Spectrometry for Characterizing Different Species of Origanum and Detecting Blends of Its Products

This study examines how freely dissolved concentrations influence the comparative hazard ranking of bisphenol A (BPA) and 24 alternative chemicals in in vitro assays. Chemical stability and bioavailable concentrations were assessed experimentally and modeled, with predicted freely dissolved concentrations generally agreeing with measurements within one order of magnitude.Exposure correction had little effect for hydrophilic compounds but substantially increased the apparent potency of hydrophobic, highly protein-bound alternatives. For example, BPAF and TCBPA ranked considerably higher when freely dissolved rather than nominal concentrations were used. The findings show that accounting for actual in vitro exposure is essential for reliable hazard assessment of BPA alternatives.<blockquote><h4>The original article</h4><h4><a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/crtoec/article/doi/10.1021/acs.chemrestox.6c00300/5442587/In-Vitro-Exposure-Assessment-Improves-Hazard">In Vitro Exposure Assessment Improves Hazard Ranking of Bisphenol A Alternatives</a></h4>Luise Henneberger*; Sophia Bardehly; Arina Kremser; Vanessa Srebny; Beate I. EscherChem. Res. Toxicol. (2026)&nbsp;<div><a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1021/acs.chemrestox.6c00300">https://doi.org/10.1021/acs.chemrestox.6c00300</a></div><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/">CC-BY 4.0</a></h6></blockquote>Selected sections from the article follow. Formats and hyperlinks were adapted from the original.<div><div><div><div><div><div><div>Bisphenol A (BPA) was used for decades as a plastic chemical, but due to its endocrine disrupting properties it is now banned for food-contact materials (<a href="javascript:;">1</a>) and thermal paper (<a href="javascript:;">2</a>) in the European Union. Numerous BPA replacement chemicals have therefore been developed, but for most of them effects to human and environmental health have not been thoroughly assessed. (<a href="javascript:;">3, 4</a>) Cell-based in vitro bioassays allow a fast screening for adverse effects and can help to identify which alternatives show similar toxicity compared to BPA itself and which ones can be considered more benign. Numerous in vitro toxicity studies have been published, but the majority has either focused on only a few of the BPA alternatives or few specific end points like estrogenicity and androgenicity (<a href="javascript:;">5, 6</a>) or adipogenesis. (<a href="javascript:;">7, 8</a>) The most comprehensive in vitro toxicity datasets for BPA and its alternatives can be found in the recent publication by Srebny et al. (<a href="javascript:;">9</a>) that reports data from six assays for BPA and 26 alternatives and in the Tox21 database, which contains data from various assays for BPA and 15 alternatives as reviewed by Adamovsky et al. (<a href="javascript:;">4</a>)</div><div>To date, comparative hazard assessment using in vitro toxicity data for BPA and its alternatives was exclusively done based on nominal effect concentrations. (<a href="javascript:;">9−12</a>) However, nominal concentrations do not necessarily correlate with the bioactive concentration, because the test concentration of the chemicals added at the beginning of the bioassay can be reduced by plastic sorption, volatilization, cellular metabolism, abiotic degradation and binding to cell culture medium constituents (<a href="javascript:;">Figure 1</a>). (<a href="javascript:;">13</a>) Some of these binding and loss processes are only relevant for certain compound classes or assay types. For example, plastic sorption was shown to be negligible for assays that use a high serum content, i.e., 10% fetal bovine serum (FBS) in 384-well plates. (<a href="javascript:;">14</a>) Furthermore, many cell lines applied in high-throughput screening assays (e.g., HEK293 cells) have limited metabolic capacity, which makes this loss process also less relevant. (<a href="javascript:;">15</a>) Volatility can be evaluated using the medium-air partition constant (Kmedium/air) of the test chemicals. Previous studies have shown that chemicals with log Kmedium/air &lt;4 are lost from the assay plates or even cross-contaminate neighboring wells and cannot be tested in open well plate formats. (<a href="javascript:;">16, 17</a>)<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Chem_Res_Toxicol_2026_Figure_1_Binding_and_loss_processes_in_cell_based_in_vitro_bioassays_9255cda1ae.png" alt="Chem. Res. Toxicol. (2026): Figure 1. Binding and loss processes in cell-based in vitro bioassays and their relevance for BPA and its alternatives. Created in BioRender. Henneberger, L. (2026) " srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Chem_Res_Toxicol_2026_Figure_1_Binding_and_loss_processes_in_cell_based_in_vitro_bioassays_9255cda1ae.png 192w," sizes="100vw" width="750" height="608"><div>Following these considerations, previous studies identified abiotic stability as a key parameter for in vitro exposure assessment that should always be measured in the first place. (<a href="javascript:;">18−20</a>) Unfortunately, stability measurements in bioassay medium are rarely published. For BPA and its two alternatives Bisphenol S (BPS) and F (BPF), medium concentrations were recently measured over time by Brenner et al. (<a href="javascript:;">21</a>) and were found to be stable for 24 h. The diglycidyl ether of BPA (BADGE) was reported to hydrolyze quickly in aqueous solution, (<a href="javascript:;">9, 22, 23</a>) which will occur in medium as well. However, for most BPA replacement chemicals the stability in assay medium is not known.</div><div>For stable compounds the binding to medium proteins and lipids will determine the bioavailable concentration. In previous studies, free fractions (ffree) in cell culture medium were measured for BPA, BPS and BPF, (<a href="javascript:;">21, 24</a>) but experimental data for other BPA alternatives are lacking. Prediction of ffree is also possible with a variety of different in vitro distribution models, (<a href="javascript:;">13</a>) but the required chemical input parameters for protein and lipid binding are also not available experimentally for the majority of the BPA alternatives, which may lead to high prediction errors.</div><div>To address the aforementioned data gaps, BPA and 24 of its alternatives with diverse physicochemical properties were tested for their chemical stability in cell culture medium in the present study. For the subset of stable chemicals, binding to bovine serum albumin (BSA) and phospholipid membranes was quantified. BSA is the most abundant protein in FBS and can be considered to be the predominant sorptive phase for BPA and its alternatives. (<a href="javascript:;">25−27</a>) The measured distribution ratios to proteins and lipids were used to validate the quantitative structure-activity relationships (QSARs) reported in previous studies (<a href="javascript:;">28, 29</a>) that allow a prediction of protein and lipid binding from the octanol-water partition constant (Kow) and speciation of the BPA alternatives. Additionally, ffree in cell culture medium was measured and compared to ffree predicted using a simple mass balance model. (<a href="javascript:;">30</a>) The experimental ffree were used to calculate relative effect potencies (REPs) of the BPA alternatives based on freely dissolved concentrations and the derived REPs were compared to published REPs based on nominal concentrations.</div></div><h4>Materials and Methods</h4><h5>Instrumental Analysis</h5>Chemical concentrations in the PBS samples after SPME extraction, in the corresponding sample extracts, as well as in the samples from the stability and membrane partitioning experiments were determined using a liquid chromatography instrument (<a target="_blank" rel="noopener noreferrer" href="https://labrulez.com/en-us/lcms/library?mainauthorItems=10&amp;search=1260+Infinity+II">1260 Infinity II, Agilent</a>) coupled to either a fluorescence detector (1100/1200 FLD), a diode array detector (DAD) or a triple quadrupole mass spectrometer (<a target="_blank" rel="noopener noreferrer" href="https://labrulez.com/en-us/lcms/library?mainauthorItems=10&amp;search=6420">Triple Quad 6420, Agilent</a>). Further details on the instrumentation including column types, instrumental conditions and limits of quantification (LOQs) are provided in the <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/crtoec/article-supplement/5442587/pdf/tx6c00300_si_001/">SI Tables S2-4</a>. Calibration standards with a concentration range of 1–10.000 ng/mL in desorption solvent or PBS (for the determination of isotherms, pin-water distribution and membrane-water partitioning) and acetonitrile blanks were measured together with the samples. The PBS samples were diluted 1:1 or 1:10 with acetonitrile according to the composition of the calibration standards.<h4>Results</h4><h5>Stability Measurements in Bioassay Medium</h5>BPA and 22 of its alternatives were found to be stable in bioassay medium (OptiMEM base medium supplemented with 2% cs-FBS). The total medium concentration for these chemicals determined after 48 h of incubation at 37°C differed less than 20% from the total medium concentration determined in the freshly prepared medium (<a href="javascript:;">Fig. 2</a>). For the most hydrophobic test chemical Bisphenol PH (BPPH) losses of 37% and 10% were observed in assay medium with 2% and 10% FBS, respectively. BADGE was completely degraded within 48 h in both types of media (<a href="javascript:;">Fig. 2</a>).<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Chem_Res_Toxicol_2026_Figure_2_Stability_of_BPA_and_24_alternatives_f4ada9114e.png" alt="Chem. Res. Toxicol. (2026): Figure 2. Stability of BPA and 24 alternatives at 37°C in assay medium (OptiMEM supplemented with 2% cs-FBS) expressed as %loss after 48 h, different symbols indicate independent experimental replicates. Stability of BADGE and BPPH was also tested in assay medium consisting of 90% DMEM with 10% untreated FBS." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Chem_Res_Toxicol_2026_Figure_2_Stability_of_BPA_and_24_alternatives_f4ada9114e.png 107w," sizes="100vw" width="750" height="1090"><h5>Bovine Serum Albumin Binding and Membrane-water Partitioning</h5><div>The SPME method was successfully optimized for BPA and 15 of the alternatives. Binding to the pin coating as well as equilibration times were found to increase with increasing hydrophobicity (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/crtoec/article-supplement/5442587/pdf/tx6c00300_si_001/">Figure S4</a>). Chemical recoveries (sum of amount in PBS and pin coating) for the optimization experiments in PBS were high (76-111%). Several chemicals showed nonlinear sorption to the pin coating, which had to be considered in the Cfree calculation (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/crtoec/article-supplement/5442587/pdf/tx6c00300_si_001/">Figure S3</a>). Despite the good performance of the SPME method, the testable concentration range was limited for some BPA alternatives due to high LOQs (e.g., 1 μg/mL for BPP and 0.5 μg/mL for BPZ).<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Chem_Res_Toxicol_2026_Figure_3_Comparison_of_measured_EXP_and_modelled_MBM_A_bovine_serum_albumin_water_distribution_ratios_d5813c1071.jpg" alt="Chem. Res. Toxicol. (2026): Figure 3. Comparison of measured (EXP) and modelled (MBM) (A) bovine serum albumin-water distribution ratios (DBSA/w) and (B) membrane or liposome-water distribution ratios (Dm/w or Dlip/w), (C) dependence of measured (EXP) and modelled (MBM) free fractions (ffree) in assay medium (OptiMEM base medium +2% cs-FBS) of the test chemicals on the membrane-water distribution ratio (Dm/w), (D) comparison of average measured (EXP) and modelled (MBM) ffree, (E) comparison of measured freely dissolved concentrations (Cfree) with dosed nominal concentration (Cnom), (F) comparison of measured (EXP) and modelled (MBM) Cfree. Solid lines in A, B, D, E and F indicate the 1:1 line, the dotted lines indicate the 1:10 and 10:1 lines. AAFE (absolute average fold error)." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Chem_Res_Toxicol_2026_Figure_3_Comparison_of_measured_EXP_and_modelled_MBM_A_bovine_serum_albumin_water_distribution_ratios_d5813c1071.jpg 216w," sizes="100vw" width="1600" height="1158"></div><div>Binding to BSA was measured for BPA and 15 of the alternatives (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/crtoec/article-supplement/5442587/pdf/tx6c00300_si_001/">Figure S5</a>, abbreviations in <a href="javascript:;">Table 1</a>). For BPF, BPAF, BP-MIBK, BPA, BPS-MAE and D8 binding isotherms were linear, while for BPT, BPZ, BzBP, Bz, BPAP, BPB, BPE and BPS-MPE binding to BSA was concentration-dependent (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/crtoec/article-supplement/5442587/pdf/tx6c00300_si_001/">Table S6</a>). <a href="javascript:;">Table 2</a> reports the mean DBSA/w. BPS and 24BPS showed weak affinities for BSA. For BPS DBSA/w could only be determined at one concentration level and no isotherm was fitted. For 24BPS no binding could be measured at any of the tested concentrations indicating fbound &lt; 20% at the tested BSA concentration of 1.56 g/L. <a href="javascript:;">Figure 3</a>A shows a comparison of the measured DBSA/w with the values predicted from log Kow by Srebny et al. (<a href="javascript:;">9</a>) Because regression models based on log Kow do not consider concentration dependence, the average DBSA/w was calculated and used for the comparison in <a href="javascript:;">Fig. 3</a>A even for the chemicals with nonlinear binding isotherms, resulting in generally larger error bars (see also <a href="javascript:;">Table 2</a>). On average, the measured DBSA/w agreed with the modelled values within a factor of 4.7 (AAFE). For most chemicals the measured and predicted DBSA/w agreed within a factor of 7. For benzylparabene (BzBP), BPS-MAE and D8 the measured DBSA/w were a factor of 17, 24, and 35 higher compared to the value predicted from log Kow. For BPA the measured log DBSA/w of 3.57 agrees well with literature data (<a href="javascript:;">29</a>) (DBSA/w = 3.65). This literature value was also used for the comparison in <a href="javascript:;">Figure 3</a>A.</div><h4>Conclusion</h4><div>The same concept as applied in the present study can also be used for other classes of chemicals. Abiotic stability should always be measured first. For unstable chemicals hazard assessment will need to include the formed transformation products as well and a concentration metric that considers temporal changes (e.g., area under the curve). The same applies to stable chemicals if cell lines with high metabolic capacity are used for in vitro testing (e.g., HepG2 or HepaRG). For stable and not quickly metabolized chemicals ECfree should be used for hazard ranking, if the chemicals show significant binding to medium proteins and lipids or high chemical diversity like the BPA alternatives investigated in the present study. Simple prediction models can provide a fast alternative to experimental determination of ffree, but they rely on the quality of the used chemical input parameters and are less accurate for organic acids that show nonlinear protein binding.</div><div>Finally, for IVIVE, metabolism of the BPA alternatives needs to be considered as well. Metabolization does not only differ between BPA and its alternatives, but also between different cell lines and between in vitro and in vivo. For mechanistic understanding of metabolism and its influence on toxicity it might be advisible to use a defined external metabolic system as used by Srebny et al. (<a href="javascript:;">9</a>) with non-metabolically competent cell lines before testing directly in metabolically competent cells. Metabolization generally decreases estrogenicity and cytotoxicity of BPA and its alternatives, (<a href="javascript:;">9</a>) but data for other end points are largely missing.</div></div></div></div></div></div></div>

In Vitro Exposure Assessment Improves Hazard Ranking of Bisphenol A Alternatives

This study establishes an integrated workflow for quantitative whole-animal elemental imaging of Caenorhabditis elegans by LA-ICP-TOF-MS. Optimized on-slide preparation using petrolatum improved specimen preservation, while oversampling during laser ablation enabled a spatial resolution of 2 μm.Quantitative elemental maps were generated using matrix-matched gelatin standards designed to mimic tissue ablation depth. The workflow addresses key challenges in sample handling, preservation, spatial resolution, and quantification, expanding the use of LA-ICP-TOF-MS for microscale metal biology and other small model organisms.<blockquote><h4>The original article</h4><h4><a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/ancham/article/98/38/28440/5431951/On-Slide-Preparation-of-Caenorhabditis-elegans">On-Slide Preparation of Caenorhabditis elegans toward Quantitative, High-Resolution LA-ICP-TOF Mass Spectrometry Imaging</a></h4>Aidan J. Reynolds# ; Aaron Sue# ; Keith MacRenaris; Thomas V. O’Halloran* ; Tian Autumn Qiu*Anal. Chem. (2026) 98 (38): 28440–28453<div><a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1021/acs.analchem.6c04271">https://doi.org/10.1021/acs.analchem.6c04271</a></div><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/">CC-BY 4.0</a></h6></blockquote>Selected sections from the article follow. Formats and hyperlinks were adapted from the original.<div><div><div><div><div><div>In this study, we established an integrated workflow consisting of sample preparation, imaging, and quantitative data analysis for whole-animal elemental imaging of C. elegans by LA-ICP-TOF-MS using petrolatum as a preferred embedding medium and achieved 2-μm spatial resolution with laser ablation oversampling. Compared to water-based embedding media, hydrocarbon-based petrolatum showed excellent preservation of C. elegans while retaining sufficient optical transparency for microscopy visualization, possessed the necessary nonvolatility for long-term storage, and was elementally pure for high-quality LA-ICP-MS imaging. With the assistance of a home-designed 3D-printed tool, uniform layer media application tool (ULMAT), embedding medium was applied as a uniform layer on top of charged microscope slides for on-slide embedding, freezing, and subsequent elemental analysis of C. elegans. An optional and additional step was also used to extract embedded worms from the embedding media layer to prepare petrolatum-coated worms. Comparisons between petrolatum-embedded worms and petrolatum-coated worms were also made to evaluate sample integrity and imaging data quality. Through several time-series experiments at ambient conditions, we evaluated sample integrity under different sample preparation approaches to determine optimal imaging time frames such that tissue decay and metal delocalization did not impede the accuracy of elemental imaging. We then characterized LA-ICP-TOF-MS imaging artifacts indicative of the stages of sample desiccation. We applied an oversampling technique in LA-ICP-TOF-MS imaging and achieved a 2-μm spatial resolution, providing high resolution imaging of C. elegans elemental content. Finally, using metal-spiked gelatin standards and ImageJ-based data analysis pipeline, we developed quantitative LA-ICP-TOF-MS imaging workflow and successfully produced quantitative elemental profiling of key biological elements in C. elegans.<h4>Experimental Section</h4><h5>Microscopy and LA-ICP-TOF-MS Imaging</h5>After sample processing including embedding, freezing and optional desiccation, brightfield, GFP and tdTomato fluorescence imaging of embedded and coated worms were taken using a Zeiss Axio Imager.Z2 upright fluorescence microscope. Embedded and coated worms were then taken for elemental analysis by LA-ICP-TOF-MS imaging using an ESL Bioimage 266 nm laser ablation system coupled to a TofWerk icpTOF S2. Samples were ablated with a laser power of 90% using a 5-μm spot size and a 3-μm overlap. Imaging cup and imaging chamber flow rates were set to 200 mL/min and 250 mL/min, respectively, using helium gas. Laser repetition rate was set to 125 Hz with a washout time of 10 ms. Plasma, auxiliary, and nebulizer gas flow were set to 14.0 L/min, 8.0 L/min, and 0.9–1.0 L/min, respectively. Measurement mode was kinetic energy discrimination (KED) using a helium gas flow of 5 mL/min. Time-of-flight elemental analysis was done using a m/z range of 14–256 at a mass resolving power of 1000. All essential microscopy and LA-ICP-TOF-MS parameters for C. elegans imaging are shown in <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/ancham/article-supplement/5431951/pdf/ac6c04271_si_001/">Table S2</a> and <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/ancham/article-supplement/5431951/pdf/ac6c04271_si_001/">Table S3</a>.<h4>Results and Discussion</h4><h5>Selection of Embedding Media To Preserve C. elegans Structural Integrity</h5>Preparation of tissue samples for LA-ICP-MS imaging requires preserving tissue morphology and native distribution of elements over possibly hours of instrumental run time. Traits for an ideal embedding medium should be elementally pure to introduce none-to-little background noise, be optically transparent for microscopy, be capable of preserving C. elegans over hours, and not be difficult for the laser to ablate through. We first evaluate the capability of embedding media and application approach to preserve C. elegans structural integrity postprocessing (i.e., after embedding, freezing, and optional desiccation) (<a href="javascript:;">Figure 2</a>A). Two types of embedding media were tested, including aqueous-based hydrophilic media such as OCT and wax-like hydrophobic media such as petrolatum. An isogenic strain of N2, SJ4144, with GFP fluorescence reporters in intestinal cells, was used to better visualize tissues, and brightfield and fluorescence microscopy were used to evaluate tissue morphology.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Anal_Chem_2026_98_38_28440_28453_Figure_2_Summary_of_three_C_elegans_sample_preparation_and_short_term_visualization_of_processed_C_elegans_74a4294b6d.png" alt="Anal. Chem. (2026) 98 (38): 28440–28453: Figure 2. Summary of three C. elegans sample preparation and short-term visualization of processed C. elegans from different preparation. (A) A combined C. elegans embedding workflow for OCT-embedding, petrolatum-embedding, and petrolatum-coating. A synchronized population of day 1 gravid adult C. elegans was rinsed with M9 and transferred to an unseeded NGM plate to let the extra M9 buffer absorb into nematode growth media prior to the embedding workflows. (B) Appearance of day 1 gravid adult SJ4144 C. elegans embedded in OCT, embedded in petrolatum, and coated in petrolatum observed before and after a 1.5-hour time period, visualizing differences in brightfield, GFP fluorescence, and preservation effectiveness. Brightfield black contrast was set to 0 for all microscopy images. OCT-embedded and petrolatum-coated brightfield white contrast was set to 16 000 and 9000, respectively. Petrolatum-coated brightfield white contrast was set to 6000. Green fluorescence black contrast was set to 150, and white contrast was set to 1500 for all microscopy images. White scale bars in microscopy images represent 100 μm." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Anal_Chem_2026_98_38_28440_28453_Figure_2_Summary_of_three_C_elegans_sample_preparation_and_short_term_visualization_of_processed_C_elegans_74a4294b6d.png 245w," sizes="100vw" width="1289" height="789">We found that the tested water-based embedding media were ineffective in preventing embedded C. elegans from desiccation and subsequent structural deformation (<a href="javascript:;">Figure 2</a>B, <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/ancham/article-supplement/5431951/pdf/ac6c04271_si_001/">Figure S2</a>). In OCT-embedded worms, the morphology and fluorescence reporter were clearly preserved immediately after the slide was taken out of the freezer (hour 0); however, signs of desiccation appeared after 1.5 h (<a href="javascript:;">Figure 2</a>B). Hygroscopic dopants such as glycerol can be added to improve water retention capabilities of these media; however, these molecules typically function as osmolytes (<a href="javascript:;">40</a>) or penetrating cryoprotectants. These additives likely displaced water from tissues, resulting in more rapid tissue desiccation. Compared to OCT, fish gelatin and glycerol-doped CMC showed better preservation of reporter fluorescence and worm body, while the wrinkled appearance of the worm cuticle indicated deformation (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/ancham/article-supplement/5431951/pdf/ac6c04271_si_001/">Figure S2</a>).<h5>Simultaneous Mapping of Multiple Elements by High-Resolution LA-ICP-TOF-MS</h5><div>The LA-ICP-TOF-MS technology provides the capability to image most elements on the periodic table simultaneously with the TOF analyzer. Using this technology, we successfully demonstrated simultaneous mapping of biologically relevant elements such as 31P, 55Mn, 56Fe, 63Cu, and 66Zn in C. elegans, exceeding previous quadrupole-based LA-ICP-MS studies on C. elegans with one or two elements and their respective isotopes. (<a href="javascript:;">31−33</a>) The metallome of C. elegans consists of Na, Mg, K, Ca, Mn, Fe, Cu, and Zn representing the most abundant metals, and lower-abundance metals such as Co, Mo, and Se. (<a href="javascript:;">53−56</a>) While LA-ICP-TOF-MS as a technology provided simultaneous visualization of all relevant elements in analyzed C. elegans, in this work, we present the five most abundant biologically relevant elements, particularly for later quantitative analysis, for their biological importance.</div><div>We visualize 31P, 55Mn, 56Fe, 63Cu, and 66Zn simultaneously in day 1 gravid adult C. elegans prepared by both petrolatum coating (<a href="javascript:;">Figure 4</a>A) and petrolatum embedding (<a href="javascript:;">Figure 4</a>B). By comparing elemental images with brightfield microscope images, we were able to observe discrete visualization of C. elegans anatomy for the assignment of elemental localization. In petrolatum-coated worms, 31P was found throughout the worm’s body and most strongly accumulated in the intestinal cells and posterior region of the worm. 31P is an essential element in biomolecules such as DNA, phospholipids, energy-storage molecules such as ATP, and as such, its abundance can reflect the cell size and activity across regions of tissue. (<a href="javascript:;">57</a>)55Mn exhibited the most discrete localization of imaged elements throughout the intestinal tract of C. elegans with a punctate pattern. This defined distribution of 55Mn has previously only been visualized using synchrotron-XFM technology and was first achieved in this work with LA-ICP-MS imaging. (<a href="javascript:;">52</a>)56Fe showed some increased background noise due to the presence of the isobaric interference ArO+; however, we used kinetic energy discrimination within the collision cell and improved 56Fe signals. 56Fe and 55Mn showed higher relative abundances in the anterior intestine in likely the grinder, with significant localization to the intestinal cells throughout the worm body. Meanwhile, 56Fe did not exhibit a punctate distribution like 55Mn throughout intestinal cells. While an essential element, 63Cu was found in low abundance throughout C. elegans, potentially due to the organism’s reduced use of the element in biological processes. (<a href="javascript:;">58</a>) Improved imaging of 63Cu can be achieved by using LA-ICP-QQQ-MS imaging if copper biology is of interest. While 55Mn and 56Fe showed enrichment in C. elegans’ anterior intestine, 66Zn showed little or no enrichment in the anterior region of C. elegans and instead showed increased abundance in the posterior region of imaged worms. Synchrotron-XFM imaging has revealed similar zinc distributions with posterior intestinal cells on day 5 C. elegans possessing high zinc content; (<a href="javascript:;">52</a>) however, our 2-μm spatial resolution is not sufficient to resolve the zinc-rich gonad arms from the intestine. Additionally, the orientation of C. elegans during imaging may confound resolving the gonad arms from the intestine. We also noticed that images from petrolatum-coated worms showed a noisier background compared to others (<a href="javascript:;">Figures 2</a>B and <a href="javascript:;">4</a>A). One likely reason is that the laser was directly ablating the bare glass slides without embedding media on top of it and therefore introduced more interfering signals from glass slides contaminants such as 56Fe from iron oxide (Fe2O3) and 66Zn from zinc oxide (ZnO). Additionally, metal contamination could be introduced during the transfer step in creating petrolatum-coated worms and increased background noises. Metal impurities may be found in adhesives such as glue, (<a href="javascript:;">59, 60</a>) which was used to construct the eyelash tool for transferring worms. Repeated cleaning of the eyelash pick between transfers using 70% ethanol solutions may result in a slow dissolution of the glue, which may have subsequently resulted in leaching of metal impurities onto the glass slide when dragged across the surface during transfer. Further investigations should be made to examine possible sources of metal contamination during sample preparation.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Anal_Chem_2026_98_38_28440_28453_Figure_4_Brightfield_microscopy_and_elemental_imaging_of_day_1_gravid_adult_wildtype_N2_C_elegans_9bdf0f4129.jpg" alt="Anal. Chem. (2026) 98 (38): 28440–28453: Figure 4. Brightfield microscopy and elemental imaging of day 1 gravid adult wildtype N2 C. elegans prepared by petrolatum-based methods. (A) Brightfield microscopy and LA-ICP-TOF-MS imaging of a petrolatum-coated C. elegans. (B) Brightfield microscopy and LA-ICP-TOF-MS imaging of a petrolatum-embedded C. elegans. LA-ICP-TOF-MS imaging was able to perform simultaneous mapping of 31P and essential trace elements including 55Mn, 56Fe, 63Cu, and 66Zn. Lower limits for all elements were set to 0 ppm, and upper limits were set to 99th percentile for all elements except 55Mn which was set to 99.9th percentile. Brightfield black contrast and white contrast were set to 0 and 9000, respectively. White scale bars represent 100 μm." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Anal_Chem_2026_98_38_28440_28453_Figure_4_Brightfield_microscopy_and_elemental_imaging_of_day_1_gravid_adult_wildtype_N2_C_elegans_9bdf0f4129.jpg 221w," sizes="100vw" width="1600" height="1128">When comparing petrolatum-coated elemental images (<a href="javascript:;">Figure 4</a>A) to petrolatum-embedded elemental images (<a href="javascript:;">Figure 4</a>B), several notable differences were observed. The background signal was drastically reduced in all ion images of petrolatum-embedded C. elegans. Elemental contaminants are present in glass slides, and with petrolatum serving as a barrier between the laser and the microscope slide, these contaminant signals are not observed through the direct ablation of glass. Additionally, minor differences in elemental localization were observed between petrolatum-embedded and -coated C. elegans. Across petrolatum-embedded replicates, elements that were found to be primarily intestinally localized in petrolatum-coated images showed somewhat broadened localization such as 31P and 56Fe. We also observed differences in concentration scaling for 31P, 55Mn, 56Fe, 63Cu, and 66Zn across imaged replicates. Such variation could be attributed to embedding media matrix effects altering plume properties and impacting spatial clarity in imaging or could be due to biological variations. Future studies should focus on characterizing the impact of worm orientation, embedding media thickness, and developmental variations on the slight differences in metal distribution.</div><h4>Conclusion</h4>LA-ICP-MS imaging is an important imaging modality for metal biology research in model animals. Previous studies have performed LA-ICP-MS imaging on C. elegans, but the sample preparation and technological limitations made it challenging to achieve high-resolution, multi-element, and quantitative imaging. (<a href="javascript:;">31−33</a>) We developed an integrated workflow that includes sample preparation, instrumental analysis and data processing to enable high-resolution LA-ICP-TOF-MS imaging with quantification on C. elegans, providing a powerful tool for future metal biology research in this classical biology model. We first developed a 3D-printed tool to create a uniform and a thin layer of viscous embedding media on glass slide for on-slide embedding of C. elegans. Three different sample preparations, OCT-embedded, petrolatum-embedded and petrolatum-coated, were evaluated using microscopy and subsequent LA-ICP-MS imaging. We demonstrated that petrolatum preserved reporter fluorescence, tissue morphology, and elemental distribution for a longer period when compared to conventional embedding media such as OCT. Through oversampling laser shots, we were able to achieve an effective 2-μm spatial resolution in LA-ICP-MS imaging, allowing for resolving cellular elemental compartmentalization that has been previously only observed in XFM studies. (<a href="javascript:;">52, 72</a>) We further established a data analysis pipeline toward quantitative LA-ICP-TOF-MS imaging. With gelatin standards, we demonstrated quantitative imaging of five endogenous elements simultaneously in one sample, allowing colocalization of worm fluorescence reporters, brightfield images and different elements.</div></div></div></div></div></div>

On-Slide Preparation of Caenorhabditis elegans toward Quantitative, High-Resolution LA-ICP-TOF Mass Spectrometry Imaging

Food

Scientific article

Science and research

Everything from the world of analytical chemistry in one place. We connect people in solving their problems. At Labrulez you will find all the necessary information easily, quickly and clearly. Stop searching and start finding.

LabRulez

Thermo Scientific Dionex IonPac CS17 IC Columns

Obtain excellent selectivity and peak shapes for hydrophobic amines in complex matrices without solvent using the Thermo Scientific Dionex IonPac CS17 column.

Obtain excellent selectivity and peak shapes for hydrophobic amines in complex matrices without solvent using the Thermo Scientific™ Dionex™ IonPac™ CS17 column. This medium-capacity, carboxylate-functionalized column is optimized for the gradient separation of hydrophobic and polyvalent amines using simple aqueous eluents and elevated temperatures (40°C). It is intended for analysis of power plant waters treated with ammonium, morpholine, or ethanolamine; chemical additives; chemical process solutions; scrubber solutions; plating baths; industrial solvents; and food samples.<h5>Gradient Separation of Common Cations and Small Polar Amines in Diverse Matrices</h5><ul><li>Hydrophilic, low-capacity column optimized for gradient separation of polyvalent and hydrophobic amines–including alkanolamines and methylamines–in complex sample matrices</li><li>Separation of moderately hydrophobic amines, including biogenic amines, alkyldiamines, and polyamines.</li><li>Minimal baseline shift and enhanced analyte sensitivity</li><li>Improved peak shape for most Thermo Scientific™ Dionex™ IonPac™ CS14, CS15, and CS16 column amine applications without the use of solvent</li><li>Optimized for simple acidic gradient applications</li><li>Compatibility with organic solvents to enhance analyte solubility, modify column selectivity, and facilitate effective column clean-up</li></ul><h5>Multiple Formats Available for Application Flexibility</h5><ul><li>4x250mm, 2x250mm analytical columns</li><li>4x50mm, 2x50mm guard columns</li><li>Longer 250mm columns facilitate higher resolution separations of more complex sample matrices</li><li>Smaller i.d. columns provide higher mass sensitivity, eluent and reagent conservation and lower operating costs.</li></ul><h4>Specifications</h4><ul><li>Crosslinking: 55% DVB</li><li>Column Capacity: 1450 μeq</li><li>For Use With (Application): Cation Exchange</li><li>Max. Pressure: 4000 psi (275 bar)</li><li>Solvent Compatibility: Acidic Eluents, 0 to 100% HPLC Solvents, Including Alcohols</li><li>Stationary phase: IonPac CS17</li><li>Format: Standard Bore</li><li>Packing Material: Ethylvinylbenzene/Divinylbenzene</li></ul>

Thermo Scientific Dionex IonPac CS18 IC Columns

Separate polar amines with the Thermo Scientific™ Dionex™ IonPac™ CS18 Cation-Exchange Column. 

Separate polar amines with the Thermo Scientific™ Dionex™ IonPac™ CS18 Cation-Exchange Column. This low-capacity, carboxylate-functionalized column is specifically optimized for the separation of common cations, small polar amines, and moderately hydrophobic and polyvalent anions using simple aqueous eluents and elevated temperatures. However, the newer Thermo Scientific™ Dionex™ IonPac™ CS19 or Dionex IonPac CS19-4μm Cation Exchange Columns are the recommended columns for these applications.<h5>Cation and Amine Separations Using Suppressed and Non-suppressed Conductivity Detection</h5><ul><li>Low-capacity column optimized for the isocratic and gradient separations of polar amines, moderately hydrophobic amines, and polyvalent cations</li><li>Can be used with suppressed and nonsuppressed conductivity detection</li><li>Nonsuppressed conductivity detection is recommended to extend calibration linearity for ammonium or weak bases</li><li>Can also be used for many of the nonsuppressed applications supported by the Dionex IonPac SCS-1 column but with much greater column stability</li><li>Optimized for simple acidic gradient separations with minimal baseline shift</li><li>Low capacity facilitates modest acid concentrations to elute polyvalent cations</li><li>Compatible with moderate amounts of organic solvents, excluding alcohols, to enhance analyte solubility, modify column selectivity, and facilitate effective column clean-up</li></ul><h5>Formats Available for Application Flexibility</h5><ul><li>2x250mm analytical columns</li><li>2x50mm guard columns</li><li>Longer 250mm columns facilitate higher resolution separations of more complex sample matrices</li><li>Smaller i.d. columns provide higher mass sensitivity, eluent and reagent conservation and lower operating costs</li></ul><h4>Specifications</h4><ul><li>Crosslinking: 55% DVB</li><li>Column Capacity: 290 μeq</li><li>For Use With (Application): Cation Exchange</li><li>Max. Pressure: 4000 psi (275 bar)</li><li>Solvent Compatibility: Acidic Eluents (pH 0 to 7), 0 to 20% HPLC Solvents, Alcohols Should be Avoided</li><li>Stationary phase: IonPac CS18</li><li>Format: Microbore</li><li>Packing Material: Ethylvinylbenzene/Divinylbenzene</li></ul>

Thermo Scientific Dionex IonPac CS19 IC Columns

Separate common inorganic cations, small polar amines and polyvalent amines using Thermo Scientific Dionex IonPac CS19 IC Columns

Separate polar amines with the Thermo Scientific™ Dionex™ IonPac™ CS19 Cation-Exchange Column. This high-capacity, carboxylate-functionalized column is specifically optimized for the separation of common cations, small polar amines, and moderately hydrophobic and polyvalent cations using simple aqueous eluents and elevated temperatures. The column is ideal for analysis of power plant waters treated with ammonium, morpholine, or ethanolamine and can also be used to analyze chemical additives, chemical process solutions, scrubber solutions, personal care products, and food samples.<h5>Analyze Common Cations and Small Polar Amines in Diverse Matrices</h5><ul><li>Simple gradient separation of small polar amines (including alkanolamines and methylamines), and moderately hydrophobic and polyvalent amines (including biogenic amines and alkyl diamines)</li><li>Optimized for simple acidic gradient separations with minimal baseline shift</li><li>High capacity facilitates the analysis of widely disparate peak pairs and high ionic strength matrices with less overloading of the column</li><li>Compatible with moderate amounts of organic solvents, excluding alcohols, to enhance analyte solubility, modify column selectivity, and facilitate effective column clean-up</li></ul><h5>Multiple Formats Available for Application Flexibility</h5><ul><li>4x250mm, 2x250mm analytical columns</li><li>4x50mm, 2x50mm guard columns</li><li>Longer 250mm columns facilitate higher resolution separations of more complex sample matrices</li><li>Smaller i.d. columns provide higher mass sensitivity, eluent and reagent conservation and lower operating costs</li></ul><h4>Specifications</h4><ul><li>Crosslinking: 55% DVB</li><li>Column Capacity: 2410 μeq</li><li>For Use With (Application): Cation Exchange</li><li>Max. Pressure: 3000 psi (207 bar)</li><li>Solvent Compatibility: Acidic Eluents (pH 0 to 7), 0 to 10% HPLC Solvents, Alcohols Should be Avoided</li><li>Stationary phase: Super Macroporous Resin</li><li>Format: Standard Bore</li><li>Packing Material: Ethylvinylbenzene/Divinylbenzene</li></ul>

Thermo Scientific Dionex IonPac CS19-4μm IC Columns

High-capacity ion-exchange column with 4 μm resin for highest resolution of cations and polar amines in complex samples. Enables fast, reliable separations and cost-effective operation with HPIC systems.

Attain the optimal combination of chromatographic speed and high resolution using the new Thermo Scientific™ Dionex™ IonPac™ CS19-4μm Capillary, Analytical, &amp; Guard Column. This high-capacity, high-resolution carboxylate-functionalized column provides excellent resolution of common cations, small polar amines, and polyvalent amines in complex sample matrices such as power plant waters treated with ammonium, morpholine, or ethanolamine, chemical additives, chemical process solutions, scrubber solutions, personal care products, and food samples. Compared to the Thermo Scientific™ Dionex™ IonPac™ CS19 column, this column uses smaller resin particles for more efficient separations resulting in more accurate peak integration and more reliable results.<h5>Highest Resolution Separation of Common Cations and Small Polar Amines in Diverse Matrices</h5><ul><li>Highest resolution, through the use of smaller resin particles, of common cations and small polar amines in complex sample matrices</li><li>Higher peak efficiency and increased peak resolution for more consistent integration and more reliable results</li><li>Easily transfer applications from the Dionex IonPac CS19 column to the 4 μm column due to the similar selectivity</li><li>Simple gradient separation of small polar amines (including alkanolamines and methylamines), and moderately hydrophobic and polyvalent amines (including biogenic amines and alkyl diamines)</li><li>High capacity facilitates injection of more concentrated samples without column overloading or peak broadening</li><li>Compatible with moderate amounts of organic solvents, excluding alcohols, to enhance analyte solubility, modify column selectivity, and facilitate effective column clean-up</li></ul><h5>Use With a High-Pressure IC System</h5>Higher resolution is achieved through the use of smaller resin particles, which produce a column backpressure over 3000 psi at the standard flow rates. A high-pressure IC system, such as the Thermo Scientific™ Dionex™ ICS-5000+ HPIC™ or the Dionex ICS-4000 Capillary HPIC system is required to operate this column under standard conditions and take advantage of elevated flow rates and faster run times.<h5>Reduce Operating Costs With Lower Eluent Requirements</h5>The Dionex IonPac CS19-4μm capillary column provides the same performance as the standard bore and microbore Dionex IonPac CS19-4μm columns because it is packed with the same material. Operating costs are reduced because the capillary system operates at only 1% of the eluent flow rate of the standard bore system, requiring less eluent and producing less waste.<h5>Multiple Formats Available for Application Flexibility</h5><ul><li>4x250mm, 2x250mm analytical columns</li><li>4x50mm, 2x50mm guard columns</li><li>0.4x250mm capillary column, 0.4x50mm capillary guard column</li><li>Longer 250mm columns facilitate higher resolution separations of more complex sample matrices</li><li>Smaller i.d. columns provide higher mass sensitivity, eluent and reagent conservation and lower operating costs</li></ul><h4>Specifications</h4><ul><li>Crosslinking: 55% DVB</li><li>Column Capacity: 2410 μeq</li><li>For Use With (Application): Cation Exchange</li><li>Max. Pressure: 5000 psi (345 bar)</li><li>Solvent Compatibility: Acidic Eluents (pH 0 to 7), 10% HPLC Solvents, Alcohols Should be Avoided</li><li>Stationary phase: IonPac CS19-4μm</li><li>Format: Standard Bore</li></ul>

Thermo Scientific Dionex IonPac CS20 IC Columns

Analyze inorganic cations and amines using the Thermo Scientific™ Dionex™ IonPac™ CS20 ion chromatography (IC) columns.

Analyze inorganic cations and amines using the Thermo Scientific™ Dionex™ IonPac™ CS20 ion chromatography (IC) columns. Designed to complement Dionex IonPac CS18 and Dionex IonPac CS19 columns, the Dionex IonPac CS20 columns provide a large separation window between monovalent and divalent cations. This allows most amines to elute after the alkali metals but before the alkaline earth metals, moving the amines away from matrix ions that would normally make quantitation difficult. Its selectivity makes the Dionex IonPac CS20 particularly useful for determining a variety of alkyl and alkanol amines.<h5>Superior performance in the separation of common inorganic cations and amines</h5><ul><li>Use the high capacity Dionex IonPac CS20 to determine inorganic cations and amines including methylamines, ethylamines, ethanolamines, and alkanolamines in diverse sample matrices</li><li>Unique stationary phase functionalized with a combination of sulfonic, phosphonic, and carboxylic acid groups can tolerate acidic samples containing up to 100mM hydronium ion (pH 1) with minimum loss of performance</li><li>Operable over a wide temperature range (15-70°C) to facilitate method development and improve critical pair separations</li><li>Compatible with 100% organic solvents (acetonitrile and acetone) to enhance analyte solubility, modify column selectivity, and facilitate effective column clean-up</li></ul><h5>Use with a high-pressure IC system</h5>A high-pressure IC system, such as the Thermo Scientific™ Dionex™ ICS-5000+ HPIC™, Dionex Integrion™ HPIC system, or the Dionex ICS-4000 Capillary HPIC system is required to operate this column under standard conditions.<h5>Reduce operating costs with lower eluent requirements</h5>The Dionex IonPac CS20 capillary columns provide the same performance as the standard bore and microbore Dionex IonPac CS20 columns because they are packed with the same material. Operating costs are reduced because the capillary system operates at only 1% of the eluent flow rate of the standard bore system, requiring less eluent and producing less waste.<h5>Multiple Formats Available</h5><ul><li>4x250mm and 2x250mm analytical columns</li><li>4x50mm and 2x50mm analytical guard columns</li><li>0.4x250mm capillary columns</li><li>0.4x50mm capillary guard columns</li><li>Smaller i.d. columns provide higher mass sensitivity, conserve eluent and reagents, and reduce operating costs</li></ul><h4>Specifications</h4><ul><li>Crosslinking: 55% DVB</li><li>Column Capacity: 3000 μeq</li><li>For Use With (Application): Cation Exchange</li><li>Max. Pressure: 5000 psi (345 bar)</li><li>Solvent Compatibility: pH 0 to 7, 0 to 100% Organic HPLC Solvents, Alcohols Should be Avoided</li><li>Stationary phase: Macroporous Resin</li><li>Format: Standard Bore</li><li>Packing Material: Ethylvinylbenzene/Divinylbenzene</li></ul>

Thermo Scientific Dionex IonPac CS21-Fast-4μm IC Columns

Resolve quaternary amine cationic polar pesticides including chlormequat, mepiquat, paraquat, and diquat with the Thermo Scientific™ Dionex™ IonPac™ CS21-Fast-4μm column. 

Resolve quaternary amine cationic polar pesticides including chlormequat, mepiquat, paraquat, and diquat with the Thermo Scientific™ Dionex™ IonPac™ CS21-Fast-4μm column. The unique selectivity of the Dionex IonPac CS21-Fast-4μm column allows it to resolve trace amounts of cationic polar pesticides in high ionic strength matrices within approximately fifteen minutes using an electrolytically generated MSA gradient. Quaternary amines are eluted away from matrix cations, making the Dionex IonPac CS21-Fast-4μm column ideal for IC-MS/MS applications where matrix ions are diverted to waste.<h5>Superior Chromatographic Performance</h5><ul><li>High capacity allows injection of complex matrices without overloading the column while maintaining excellent peak shapes for lower concentration analytes.</li><li>Quickly separate trace levels of the four major quaternary amine cationic polar pesticides chlormequat, mepiquat, paraquat, and diquat in high ionic strength matrices using an MSA gradient.</li><li>Separate other cationic pesticides of interest including diethanolamine, triethanolamine, N-N-dimethylhydrazine, trimethylsulfonium, morpholine, melamine, streptomycin, and nereistoxin.</li></ul><h5>Specifically designed for IC-MS/MS applications</h5><ul><li>Completely resolves paraquat and diquat, species with similar masses.</li><li>Available in microbore format that is compatible with MS flow rates.</li><li>Selectivity allows matrix ions to be diverted to waste which keeps the MS source cleaner.</li><li>Solvent compatible (up to 100% acetonitrile and 20% isopropyl alcohol).</li><li>Fast analysis of cationic polar pesticides in food, beverages, and environmental waters.</li></ul><h5>Use with a High-Pressure IC system</h5>A high-pressure IC system, such as the <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/410">Thermo Scientific™ Dionex™ ICS-6000 HPIC system</a> or <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/408">Thermo Scientific™ Dionex™ Integrion™ HPIC system</a> is required to operate this column under standard conditions.<h4>Specifications</h4><ul><li>Crosslinking: 80% DVB</li><li>Column Capacity: 110 μeq</li><li>For Use With (Application): Cation Exchange</li><li>Max. Pressure: 5000 psi (345 bar)</li><li>Solvent Compatibility: pH 0-7, HPLC solvents (100% acetonitrile and up to 20% isopropyl alcohol), primary and secondary alcohols should be avoided)</li><li>Format: Microbore</li><li>Packing Material: Ethylvinylbenzene/Divinylbenzene</li></ul>

Thermo Scientific SurePac Bio 550 SEC MDi HPLC Columns

SurePac™ Bio 550 SEC MDi™ column delivers high-resolution, reproducible AAV size-based separations with 3 μm silica, 550 Å pores, and bioinert hardware for optimal recovery and QC reliability.

Experience the future of Size-Exclusion Chromatography (SEC) with SurePac™ Bio 550 SEC MDi™ analytical columns and guards exclusively designed to deliver robust and reproducible performance at high resolution and throughput to accelerate your therapeutics analysis process. The column's groundbreaking MDi™ technology integrates our advanced 3 μm monodisperse silica particle platform with bioinert hardware to ensure superior reliability for best sample recovery. SurePac™ Bio 550 SEC MDi™ column is ideal for AAV gene therapeutics analysis and offers excellent selectivity due to the dedicated smaller particle (3 μm) size combined with wide-pore (550Å) for separating monomeric AAVs from aggregates based on their size differences.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Thermo_Scientific_Sure_Pac_Bio_550_SEC_M_Di_HPLC_Columns_3_8391a584e0.jpg" alt="Thermo Scientific: SEM image of 3μm monodisperse silica particles (left) vs. 3 μm polydisperse particles (right)" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Thermo_Scientific_Sure_Pac_Bio_550_SEC_M_Di_HPLC_Columns_3_8391a584e0.jpg 245w," sizes="100vw" width="1023" height="508">SurePac Bio 550 SEC MDi columns and guards are based on high-purity, spherical, porous (550 Å), 3 μm monodispersed silica particles that are covalently modified with a proprietary diol hydrophilic layer. This unique design yields shorter diffusion distances and enhanced reproducible mass transfer and narrower peaks. The consistent size of these particles facilitates precise control over media synthesis and column packing, significantly improving column-to-column and lot-to-lot reproducibility. The columns are housed in a hydrophilic bioinert-coated stainless-steel hardware to eliminate secondary interactions, ensuring optimal performance during the initial injection process.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Thermo_Scientific_Sure_Pac_Bio_550_SEC_M_Di_HPLC_Columns_043f131056.jpg" alt="Thermo Scientific: SurePac Bio 550 SEC MDi HPLC Columns" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Thermo_Scientific_Sure_Pac_Bio_550_SEC_M_Di_HPLC_Columns_043f131056.jpg 156w," sizes="100vw" width="650" height="650"><ul><li>Ideal for AAV gene therapy characterization and quality control assessment due to selectivity of the dedicated smaller particle (3 μm) combined with wide-pore (550Å) size</li><li>Superior column-to-column and lot-to-lot reproducibility eliminates column variability as a concern in stability and QA/QC testing</li><li>High-efficiency peaks with excellent recovery</li><li>Higher resolution and throughput for fast turnaround time without sacrificing performance</li><li>Bioinert hardware to eliminate analyte adsorption</li></ul><h4>Specifications</h4><ul><li>Max. Pressure: 3500 psi (241 bar)</li><li>Packing Material: Monodisperse Silica Resin</li><li>Flow Rate: 0.6 mL/min</li><li>Temperature: 20°C to 60°C</li><li>Phase: Size Exclusion</li><li>Particle Size: 3 μm</li><li>pH: 2 to 8</li></ul>

Thermo Scientific SureSTART Vials and Well Plates Collection

Start your analysis with confidence using SureSTART vials, caps, well plates, and kits—offering full compatibility, quality materials, and performance across three levels.

<h4>Streamlined choice. Trusted quality.</h4>Start your analysis with confidence using Thermo Scientific™ SureSTART™ vials, caps, inserts, well plates, mats, and certified kits designed to meet your analytical, regulatory, and performance requirements. With full instrument compatibility, high material quality, and consistent performance across three defined levels, the SureSTART collection offers a smarter way to choose the right sample containment solution for your workflow.<h3>Why choose SureSTART?</h3><ul><li>Proven reliability: Every product is manufactured and certified to meet physical specifications—no weak links in your workflow.</li><li>Clear selection: Three performance levels help you balance sensitivity, robustness, and cost, now visually marked with one, two, or three waves on the vial.</li><li>Universal compatibility: Designed for seamless integration with all major GC, HPLC/UHPLC, and MS autosamplers across all vendors.</li><li>Certified cleanliness: Products are manufactured using the purest glass and plastics with low extractables and leachables, including GOLD-grade and silanized glass.</li><li>Maximum sample integrity: Minimize analyte loss and background peaks with precision-engineered sealing, surface chemistry, and material composition.</li><li>Bulk savings &amp; simplified inventory: Available in multiple pack sizes, performance levels, and formats to support your lab’s needs and budget.</li></ul><h3>The Three Performance Levels</h3><ul><li>Level 1 – Everyday analysis: For general-purpose GC/HPLC detection (e.g. UV/Vis, FID, RI). These chromatography-approved products are ideal for routine analyses with cost-efficiency in mind.</li><li>Level 2 – High-throughput analysis: Designed for regulated labs requiring robust and reproducible data, especially when using MS detectors for routine quantification.</li><li>Level 3 – High performance: For the most sensitive and selective analyses near the method detection limit. Packed in cleanroom environments and made with ultra-pure materials for maximum sample security and MS compatibility.</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Thermo_Scientific_Sure_START_Vials_and_Well_Plates_Collection_5a8b0da936.jpg" alt="Thermo Scientific SureSTART Vials and Well Plates Collection: Three performance levels help you balance sensitivity, robustness, and cost, now visually marked with one, two, or three waves on the vial." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Thermo_Scientific_Sure_START_Vials_and_Well_Plates_Collection_5a8b0da936.jpg 245w," sizes="100vw" width="1182" height="270"><h3>SureSTART Certified Vial and Cap Kits</h3><ul><li>Specification Certified: Routine analyses – Certified for physical specifications; no individual certificate.</li><li>LC/GC Certified: Chromatography-grade – Tested for 15 physical parameters with LC-UV &amp; GC-FID; certificate included.</li><li>MSCERT: For LC-MS/GC-MS – Certified low-adsorption kits tested with MS; includes SureStop™ vials with AVCS™ caps.</li><li>MSCERT+: For trace-level MS or DIA – Pre-cleaned, tested with LC-MS/GC-MS, and sold only as kits to ensure purity.</li><li>Application Certified: Pre-matched kits for specific instruments or validated applications.</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Thermo_Scientific_Sure_START_Vials_and_Well_Plates_Collection_2_fef6049d71.jpg" alt="Thermo Scientific SureSTART Vials and Well Plates Collection: There are several factors to consider when choosing a vial or well plate for your application. The table below will help guide you through this process to determine what type of product/performance level is most suitable for your application requirements." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Thermo_Scientific_Sure_START_Vials_and_Well_Plates_Collection_2_fef6049d71.jpg 204w," sizes="100vw" width="1515" height="1159"><h3>SureSTART Well Plates and Mats</h3>Thermo Scientific™ WebSeal™ well plates are ideal for laboratories seeking to increase autosampler capacity, reduce solvent usage, and streamline high-throughput workflows. Available in 96- and 384-well formats, they offer a certified alternative to traditional vials and are fully compatible with automated SPE/SLE platforms.<ul><li>Space-saving efficiency: Replace vials with well plates to increase sample capacity up to 8× and reduce storage footprint.</li><li>Flexible performance levels:<ul><li>Level 1: Standard plates for routine, non-regulated use (GC-tested).</li><li>Level 2: Low-bleed plates and high-performance mats, validated for LC-MS/GC-MS.</li><li>Level 3: Premium WebSeal Plate+ with glass-coated plastic wells—ideal for trace analytes and protein adsorption control.</li></ul></li><li>Solvent stability and clean sample contact: WebSeal Plate+ uses nanolayered silicon dioxide for minimal extractables and ultra-low adsorption.</li><li>Compatible sealing options:<ul><li>Silicone mats: For long-term storage and consistent results.</li><li>Pre-slit mats: For autosampler injection without evaporation or contamination.</li><li>Adhesive seals: For single-use workflows and re-sealing options with cavity protection.</li></ul></li></ul>Whether you work with polar solvents, proteins, or trace-level analyses, SureSTART well plates and sealing accessories help you optimize throughput, precision, and data confidence across all chromatography workflows.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Thermo_Scientific_Sure_START_Vials_and_Well_Plates_Collection_3_abce3dd960.jpg" alt="Thermo Scientific SureSTART Vials and Well Plates Collection: Selecting the perfect Thermo Scientific WebSeal well plates and mats for your chromatography requirements is easy using our selector tools and resources." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Thermo_Scientific_Sure_START_Vials_and_Well_Plates_Collection_3_abce3dd960.jpg 245w," sizes="100vw" width="1516" height="902">

Thermo Scientific SurePac Oligo RP MDi HPLC Columns

Thermo Scientific SurePac Oligo RP MDi is a bioinert 2.1 × 100 mm Poly-DVB column for high-resolution RP-LC and LC-MS separation of short to large oligonucleotides across pH 2–12.

Thermo Scientific SurePac™ Oligo RP MDi™ is a bioinert polymeric reversed-phase column purpose-built for HPLC and LC-MS analysis of oligonucleotides and nucleic acids. It combines monodisperse supermacroporous Poly-DVB packing with a metal-free flow path to minimize unwanted interactions between oligonucleotides and metal surfaces. This supports high recovery, clean peak shapes, and reproducible separations for short, long, modified, and analytically challenging sequences.The column is optimized for ion-pair reversed-phase LC-MS and is compatible with commonly used ion-pairing systems such as HFIP/TEA. Its robust polymeric stationary phase supports operation across pH 2–12 and temperatures up to 90 °C, enabling demanding gradients, closely related impurity separations, and workflows spanning R&amp;D through routine QC.<h4>Poly-DVB Stationary Phase</h4>SurePac Oligo RP MDi uses a Poly-DVB polymeric stationary phase. Compared with conventional silica-based materials, the polymeric packing provides broad pH compatibility and robust operation at elevated temperatures.This is particularly valuable for oligonucleotide methods requiring:<ul><li>elevated pH,</li><li>increased temperature,</li><li>high organic content,</li><li>rapid gradients,</li><li>repeated routine analyses.</li></ul><h4>Supermacroporous Architecture</h4>The proprietary supermacroporous polymeric packing is designed to provide efficient mass transfer for larger biomolecules.The column supports separation of:<ul><li>short oligonucleotides,</li><li>therapeutic oligonucleotides,</li><li>long DNA/RNA sequences,</li><li>chemically modified oligonucleotides,</li><li>ultra-large oligonucleotides and intact nucleic acids.</li></ul><h4>Bioinert Hardware</h4>Oligonucleotide phosphate groups can interact with metallic surfaces within conventional chromatographic flow paths.The bioinert design helps:<ul><li>minimize analyte adsorption,</li><li>improve recovery,</li><li>reduce peak tailing,</li><li>improve reproducibility,</li><li>limit loss of low-level or sensitive sequences.</li></ul>This makes the column particularly suitable for bioinert UHPLC and LC-MS workflows.<h4>Ion-Pair RP LC-MS</h4>SurePac Oligo RP MDi is optimized for ion-pair reversed-phase chromatography.Compatibility with ion-pairing reagents such as HFIP/TEA supports LC-MS workflows requiring:<ul><li>reproducible retention,</li><li>high chromatographic selectivity,</li><li>efficient MS detection,</li><li>resolution of closely related sequences,</li><li>quantitation of main components and impurities.</li></ul><h4>Impurity Profiling</h4>The column provides the resolving power required for structurally similar oligonucleotide species, including:<ul><li>n−1 / n−2 truncation impurities,</li><li>extended sequences,</li><li>sequence variants,</li><li>synthesis by-products,</li><li>degradation products,</li><li>chemically modified species.</li></ul><h4>Technical Specifications</h4><ul><li>Column Format: Analytical</li><li>Separation Mode: Reversed phase</li><li>Application: Oligonucleotide and nucleic acid analysis</li><li>Stationary Phase: Poly-DVB</li><li>Packing Material: Polymeric</li><li>Pore Structure: Proprietary supermacroporous</li><li>Particle Size: 2.5 µm</li><li>Recommended Flow Rate: 0.2–0.6 mL/min</li><li>Maximum Pressure: 448 bar / 6500 psi</li><li>Temperature Range: 5–90 °C</li><li>pH Range: 2–12</li><li>Hardware: Bioinert / metal-free flow path</li><li>Compatible Techniques: HPLC, UHPLC, LC-UV, LC-MS</li></ul><h4>Typical Applications</h4><ul><li>Therapeutic oligonucleotides</li><li>DNA oligonucleotides</li><li>RNA oligonucleotides</li><li>Chemically modified oligonucleotides</li><li>Long oligonucleotides</li><li>Nucleic acids</li><li>Oligonucleotide impurity profiling</li><li>Truncation impurity analysis</li><li>LC-MS characterization</li><li>LC-UV analysis</li><li>Method development</li><li>R&amp;D</li><li>Biopharmaceutical analysis</li><li>QA/QC</li></ul>

Thermo Scientific SurePac Protein RP MDi HPLC Columns

Thermo Scientific SurePac Protein RP MDi is a bioinert 2.1 × 100 mm Poly-DVB column for high-resolution RP-LC and LC-MS analysis of intact proteins, mAbs, antibody subunits, and ADCs across pH 2–12.

Thermo Scientific SurePac™ Protein RP MDi™ is a bioinert polymeric reversed-phase column engineered for robust HPLC, UHPLC, and LC-MS analysis of intact proteins, monoclonal antibodies (mAbs), antibody subunits, and antibody-drug conjugates (ADCs). Its bioinert, metal-free flow path minimizes unwanted interactions between proteins and column hardware, supporting high recovery, reproducible peak shape, and consistent separation performance.The column uses monodisperse, supermacroporous Poly-DVB polymeric particles designed for efficient separation of large biomolecules. A broad pH range of 2–12 and operating temperatures up to 90 °C provide the flexibility required for demanding biopharmaceutical workflows and elevated-temperature LC-MS methods.<h4>Poly-DVB Stationary Phase</h4>SurePac Protein RP MDi uses a polymeric Poly-DVB stationary phase that provides broad chemical and thermal stability.The material supports methods involving:<ul><li>elevated temperatures,</li><li>high organic content,</li><li>rapid gradients,</li><li>a broad pH range.</li></ul>This flexibility is particularly valuable for optimization of intact-protein reversed-phase separations.<h4>Supermacroporous Architecture</h4>The proprietary supermacroporous particles are designed to provide efficient mass transfer for large biomolecules.Representative analytes include:<ul><li>intact proteins,</li><li>large therapeutic proteins,</li><li>monoclonal antibodies,</li><li>mAb subunits,</li><li>ADCs,</li><li>protein variants and isoforms.</li></ul><h4>Bioinert Hardware</h4>Protein interactions with metallic chromatographic surfaces can contribute to adsorption, analyte loss, or altered peak shape.The bioinert design helps:<ul><li>minimize nonspecific adsorption,</li><li>improve analyte recovery,</li><li>enhance peak symmetry,</li><li>improve reproducibility,</li><li>reduce variability for sensitive therapeutic proteins.</li></ul><h4>LC-MS Optimization</h4>SurePac Protein RP MDi is designed for LC-MS protein workflows and is compatible with MS-friendly mobile phases.Representative applications include:<ul><li>intact-mass analysis,</li><li>protein-variant characterization,</li><li>mAb analysis,</li><li>ADC characterization,</li><li>biopharmaceutical development and quality control.</li></ul><h4>High-Temperature Operation</h4>The column supports temperatures up to 90 °C, providing additional flexibility for reversed-phase protein separations.Elevated temperatures can support:<ul><li>improved mass transfer,</li><li>reduced mobile-phase viscosity,</li><li>optimized selectivity,</li><li>improved peak shape,</li><li>faster chromatographic methods.</li></ul><h4>Technical Specifications</h4><ul><li>Column Format: Analytical</li><li>Separation Mode: Reversed phase</li><li>Application: Intact proteins, mAbs, antibody subunits, and ADCs</li><li>Stationary Phase: Poly-DVB</li><li>Packing Material: Polymeric</li><li>Pore Structure: Proprietary supermacroporous</li><li>Particle Size: 2.5 µm</li><li>Recommended Flow Rate: 0.2–0.6 mL/min</li><li>Maximum Pressure: 448 bar / 6500 psi</li><li>Temperature Range: 5–90 °C</li><li>pH Range: 2–12</li><li>Hardware: Bioinert, metal-free flow path</li><li>Compatible Techniques: HPLC, UHPLC, LC-UV, LC-MS</li></ul><h4>Typical Applications</h4><ul><li>Intact proteins</li><li>Monoclonal antibodies</li><li>Antibody subunits</li><li>Antibody-drug conjugates</li><li>Therapeutic proteins</li><li>Protein variants</li><li>Protein isoforms</li><li>Biopharmaceutical characterization</li><li>Protein LC-MS</li><li>Method development</li><li>R&amp;D</li><li>QA/QC</li></ul>

Products focused on Consumables distributed by Thermo Fisher Scientific (EMEA) - page 1

Related content

On-Slide Preparation of Caenorhabditis elegans toward Quantitative, High-Resolution LA-ICP-TOF Mass Spectrometry Imaging

In Vitro Exposure Assessment Improves Hazard Ranking of Bisphenol A Alternatives

Gas Chromatography-Ion Mobility Spectrometry for Characterizing Different Species of Origanum and Detecting Blends of Its Products