Post-translational modifications (PTMs) are where so much of biology’s complexity lives, but they are also some of the hardest molecular features to analyze with confidence. Phosphorylation, asymmetric dimethylarginine (ADMA), and O-GlcNAcylation (O-GlcNAc) often occur at low abundance, can be highly labile, and frequently require precise site localization to understand their biological meaning. This<a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/tn_004377_ov_phosphorylation_ptm_etd_excedion_pro_tn004377_na_en_71f681655f.pdf"> technical note </a>shows how the <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1958">Thermo Scientific Orbitrap Excedion Pro Hybrid Mass Spectrometer</a> helps address those challenges by combining fast, sensitive performance with complementary <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/article/7217">HCD and EThcD fragmentation</a> workflows.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Thermo_Fisher_Scientific_Phosphorylation_ADMA_and_O_Glc_N_Ac_Analysis_on_the_Orbitrap_Excedion_Pro_Mass_Spectrometer_d24a5de98e.jpg" alt="Thermo Fisher Scientific: Phosphorylation, ADMA, and O-GlcNAc Analysis on the Orbitrap Excedion Pro Mass Spectrometer" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Thermo_Fisher_Scientific_Phosphorylation_ADMA_and_O_Glc_N_Ac_Analysis_on_the_Orbitrap_Excedion_Pro_Mass_Spectrometer_d24a5de98e.jpg 245w," sizes="100vw" width="1024" height="512">Using enriched PTM samples and automated data-dependent acquisition, the study demonstrates that the Orbitrap Excedion Pro MS can deliver both depth and confidence across multiple PTM classes. For phosphorylation analysis, the platform identified 5,892 unique phosphosites from IMAC-enriched samples and 2,941 unique phosphotyrosine sites after phosphotyrosine enrichment, highlighting strong performance for both broad and highly targeted signaling studies. Just as importantly, the data show that HCD and EThcD provide complementary value, with each fragmentation method contributing unique site identifications and helping resolve ambiguous assignments.The note also highlights the value of EThcD for more analytically demanding PTMs. In ADMA-enriched samples, EThcD delivered more ADMA peptide-spectrum matches and more unique modified peptides than HCD, supporting improved confidence in site characterization. For O-glycopeptides, the Orbitrap Excedion Pro MS uses an intelligent HCD-product-dependent-EThcD strategy that triggers EThcD only when oxonium ions are detected, improving productivity while preserving the fragmentation detail needed for confident glycosite localization.Overall, this technical note shows how Orbitrap Excedion Pro MS enables researchers to go deeper into PTM biology with greater sensitivity, better site confidence, and smarter acquisition. For scientists studying signaling, regulation, and disease mechanisms, it presents a powerful approach for expanding PTM coverage without compromising analytical rigor.<blockquote><h5><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/tn_004377_ov_phosphorylation_ptm_etd_excedion_pro_tn004377_na_en_71f681655f.pdf">Download the technical note "Advancing phosphorylation, ADMA, and O-GlcNAc PTM analysis with HCD and EThcD on the Orbitrap Excedion Pro mass spectrometer"</a></h5></blockquote>Visit us on&nbsp;<a target="_blank" rel="noopener noreferrer" href="https://www.linkedin.com/showcase/72003132/admin/dashboard/">LinkedIn:</a>&nbsp;#PTM #OrbitrapExcedionPro #glycosylation #phosphorylation

Phosphorylation, ADMA, and O-GlcNAc Analysis on the Orbitrap Excedion Pro Mass Spectrometer

<h3>Refractive Index (RI) Detection in HPLC – Making Invisible Compounds Visible</h3>When HPLC detectors are discussed, UV-Vis absorbance detection is often the first technique that comes to mind. Its popularity is easy to understand: it is sensitive, selective, and suitable for a wide range of compounds. But what happens when the analyte does not absorb ultraviolet or visible light?This is where the <a target="_blank" rel="noopener noreferrer" href="https://labrulez.com/en-us/all/products/2429">Refractive Index Detector (RID)</a> becomes particularly useful. Reliable, versatile, and often described as a “universal detector” for HPLC, RI detection can reveal compounds that remain invisible to many optical detectors. For substances such as sugars, polymers, lipids, or alcohols, it is often an important analytical option.Let’s look at how RI detection works, where it performs best, what its main limitations are, and how to achieve stable, reproducible results.<h4>How RI Detection Works</h4>When light passes from one medium into another, its path changes direction, or refracts, depending on the phase velocity and angle of incidence. This phenomenon is described by Snell’s law, with the extent of refraction determined by the refractive index (RI) of the medium (Figure 1).<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Figure_1_Refraction_of_light_at_the_interface_between_two_media_with_different_refractive_indices_baa4aad28c.webp" alt="KNAUER: Figure 1: Refraction of light at the interface between two media with different refractive indices, where n₁ &gt; n₂. Since the velocity is lower in the second medium (v₂ &lt; v₁), the angle of refraction α₂ is less than the angle of incidence α₁." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Figure_1_Refraction_of_light_at_the_interface_between_two_media_with_different_refractive_indices_baa4aad28c.webp 238w," sizes="100vw" width="1024" height="670">In HPLC, an RI detector monitors small changes in the refractive index of the mobile phase as compounds elute from the column. Because each substance has its own refractive index, even relatively small changes in the composition of the column effluent can generate a measurable response.Modern RI detectors generally use a differential optical design (Figure 2). Two optical paths are continuously compared: one passes through a reference cell containing pure mobile phase, while the other passes through a sample cell containing the column effluent, i.e. mobile phase plus analyte.A light source, commonly an LED or tungsten lamp, illuminates both cells. Changes in refractive index alter the path of the light, and a photodiode detects the resulting deviation.When only mobile phase is present, the two optical paths are effectively identical and no significant detector response is produced. As an analyte enters the sample cell, however, the refractive index changes. The light beam is slightly deflected, creating an optical imbalance and consequently a change in light intensity.The detector converts this change into an electrical signal, which appears as a chromatographic peak. Because the response is related to analyte concentration, RI detection can also be used for quantitative analysis.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Figure_2_Schematic_of_a_differential_RI_detector_with_dual_flow_cell_6299f55b17.webp" alt="KNAUER: Figure 2: Schematic of a differential RI detector with dual flow cell. The sample cell carries column effluent; the reference cell contains pure mobile phase. A light beam passes through both and forms a slit image on a photodiode. Any analyte-induced change in refractive index alters the beam’s path, shifting the image on the photodiode and generating a signal peak." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Figure_2_Schematic_of_a_differential_RI_detector_with_dual_flow_cell_6299f55b17.webp 245w," sizes="100vw" width="1024" height="524">For reliable measurements, the reference cell must always contain the same mobile phase as the sample cell, but without analyte. It therefore needs to be refreshed regularly with clean mobile phase, commonly using a switching valve and/or T-piece (Figure 3).<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Figure_3_Flow_path_in_the_AZURA_RID_2_1_L_during_analysis_left_and_flushing_right_e6bc30acef.webp" alt="KNAUER: Figure 3: Flow path in the AZURA® RID 2.1L during analysis (left) and flushing (right). During analysis, solvent flows from the IN port through the heat exchanger and sample cell, then continues through the T piece and flush valve to the OUT port. During flushing, the valve redirects the flow through the T piece so the solvent passes a second heat exchanger and reference cell before exiting via the OUT port." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Figure_3_Flow_path_in_the_AZURA_RID_2_1_L_during_analysis_left_and_flushing_right_e6bc30acef.webp 245w," sizes="100vw" width="1024" height="410">It is important to remember that refractive index depends on both light wavelength and medium density. The wavelength is fixed by the optical design of the detector, but density—and therefore refractive index—changes with temperature, pressure, and composition.For this reason, RI detection is particularly sensitive to changes in operating conditions. Stable measurements depend heavily on maintaining a tightly controlled analytical environment.<h4>Why Choose RI Detection?</h4>RI detectors become especially valuable when other detector types cannot provide a useful response. They may be less sophisticated than some modern detection technologies, but several characteristics make them indispensable for particular applications.<h5>Broad Applicability</h5>An RID can detect virtually any compound that produces a change in the refractive index of the mobile phase. No UV-absorbing chromophore is required.Because almost every dissolved substance changes refractive index to some degree, RI detection is commonly regarded as a universal detection technique. Typical analytes include sugars, alcohols, lipids, fatty acids, and polymers.<h5>Non-Destructive Detection</h5>RI measurement does not destroy the analyte. This makes it useful in workflows where the separated compound needs to be collected or analyzed further, including preparative chromatography.KNAUER’s <a target="_blank" rel="noopener noreferrer" href="https://store.knauer.net/shop/add38-azura-r-rid-2-1l-highflow-preparative-refractive-index-detector-62927?category=75">AZURA® RID 2.1L for preparative applications</a>, for example, supports flow rates up to 100 mL/min.<h5>Simple and Reliable Operation</h5>RI detectors are suitable for aqueous and many organic mobile phases as long as the solvent composition remains constant.Under stable isocratic conditions, they are relatively straightforward to use, robust, and require comparatively little maintenance.<h5>Direct Detection Without Derivatization</h5>Analytes do not need to be derivatized or labelled before RI detection. If a compound is soluble in the mobile phase and produces a sufficient difference in refractive index, it can be detected directly.This simplifies sample preparation and reduces additional handling steps that could introduce variability or error.These characteristics make RI detection particularly attractive for routine applications such as lactose determination in milk or polymer purity testing.<h5>Limitations of RI Detection</h5>Universal detection comes with several practical compromises. RI detectors require highly stable conditions and can be considerably more sensitive to environmental and system changes than other common HPLC detectors.<h5>High Temperature Sensitivity</h5>Refractive index is strongly influenced by temperature. For aqueous solvents, the change in refractive index with temperature is approximately dn/dT ≈ 10⁻⁴/°C.Even small temperature fluctuations can therefore produce baseline drift that may be larger than the analytical signal itself.Modern RI detectors use thermostated compartments and heat exchangers to stabilize the temperature of the flow cell. This improves accuracy and reproducibility, although the heat exchangers introduce additional system volume that can contribute to peak broadening compared with UV detection.<h5>Limited Compatibility With Gradient Elution</h5>RI detection is essentially restricted to isocratic chromatography.Changing the composition of the mobile phase during a gradient produces a much larger change in refractive index than the analyte itself. The resulting baseline shift can easily overwhelm chromatographic peaks.A stable RI baseline therefore requires the sample and reference cells to contain the same mobile-phase composition throughout the analysis.<h5>Lower Sensitivity</h5>Compared with UV detection, RI detection is generally about one to two orders of magnitude less sensitive.Typical detection limits are in the µg–mg/mL range, making RID less suitable for trace-level analysis or impurity profiling.<h5>Limited Pressure Tolerance</h5>RI flow cells can tolerate only moderate backpressure. When several detectors are connected in series, the RI detector should therefore normally be positioned last.<h5>Longer Equilibration</h5>RID systems require time to reach thermal and optical stability. Warm-up and equilibration can take hours before a sufficiently stable baseline is obtained.<h5>Sensitivity to Baseline Disturbances</h5>Because the detector responds to any change in refractive index, many factors can affect the baseline.Temperature fluctuations, unstable flow or pressure, pump pulsation, air bubbles, inadequate solvent mixing, and impurities in the mobile phase can all lead to noise, drift, or false signals.Clean operation and stable system conditions are therefore essential.<h4>How to Get the Best Performance From an RI Detector</h4>Successful RI detection can largely be summarized in one word: stability.Small variations in temperature, flow, solvent composition, or pressure can quickly become visible in the chromatographic baseline. Careful system preparation and handling can therefore make a major difference.<h5>Maintain a Stable Temperature</h5>Thermal equilibration should be one of the first priorities.Allow the detector, column, and mobile phase to equilibrate fully before beginning analysis, ideally for at least 60 minutes. A column oven can help maintain stable conditions, and the column and detector should be operated at the same temperature whenever possible.Environmental influences such as direct sunlight, air currents, or day-to-night laboratory temperature fluctuations should also be minimized.<h5>Use Isocratic Methods</h5>Keep the mobile-phase composition constant throughout the run.If the separation requires gradient elution, an RI detector is generally not the appropriate choice.<h5>Degas the Mobile Phase and Keep the System Clean</h5>Use well-degassed, particle-free mobile phases and make sure the LC system is properly primed.An in-line degasser can help prevent bubble formation. Tubing, solvent reservoirs, and the entire flow path should also be kept clean because even small bubbles or contaminants can generate spikes, noise, or other baseline disturbances.<h5>Match the Sample Solvent Carefully</h5>Whenever possible, prepare samples directly in the mobile phase or in a solvent with very similar composition.Large differences between the injection solvent and mobile phase can produce strong refractive-index disturbances around the void volume.Filtering samples also helps reduce the risk of blockages and protects the detector flow cell.<h5>Keep Flow and Pressure Stable</h5>Maintain a constant flow rate and avoid abrupt pressure changes, excessive pump pulsation, or leaks.A restriction capillary or back-pressure regulator positioned after the flow cell may help stabilize pressure, although these measures cannot compensate for noise caused by a poorly performing pump.<h5>Maintenance and Practical Considerations</h5>Flush the reference cell regularly with fresh mobile phase. The mobile phase itself should also be replaced periodically to reduce microbial growth or compositional changes caused by evaporation.When changing solvent systems, flush the instrument with mutually miscible solvents and allow sufficient time for the new system to equilibrate fully.Where appropriate, mobile-phase recycling or a low-flow standby mode can help reduce solvent consumption and shorten restart times between analytical sequences.<blockquote>👉 Pro Tip: Keep an eye on the baseline. A stable baseline is one of the best signs that the RID has equilibrated properly. Negative peaks are not necessarily an error—they simply indicate that the analyte has a lower refractive index than the mobile phase.</blockquote><h5>The Bottom Line</h5>With careful control of temperature, mobile-phase composition, pressure, and cleanliness, an RI detector can provide stable baselines and consistent quantitative data.Keep the system clean, maintain constant operating conditions, and allow sufficient equilibration time, and even this demanding HPLC “diva” can deliver highly reliable results.<h4>Typical Applications: Where RI Detection Performs Best</h4>RI detection is particularly useful for substances that do not absorb UV light strongly and therefore cannot be detected effectively using conventional UV/VIS detectors.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_AI_Figure_4_Common_uses_of_RI_detection_in_HPLC_d84d8458dc.webp" alt="KNAUER / AI: Figure 4: Common uses of RI detection in HPLC" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_AI_Figure_4_Common_uses_of_RI_detection_in_HPLC_d84d8458dc.webp 245w," sizes="100vw" width="1024" height="433">Typical analytes include sugars, alcohols, fatty acids, polymers, lipids, and other small organic molecules without strong chromophores.<h5>Some common application areas include:</h5><ul><li>Carbohydrate and sugar analysis, including determination of glucose, fructose, sucrose, or lactose in food and beverages. HPLC-RI has been used for <a target="_blank" rel="noopener noreferrer" href="https://labrulez.com/pdf/VFD_0195_sec_for_fingerprint_analysis_of_gummy_candies_ce5349cd95.pdf">product quality control of gummy candies</a>, with further discussion available in this <a target="_blank" rel="noopener noreferrer" href="https://labrulez.com/en-us/all/article/7186">related blog post</a>.</li><li>KNAUER’s AZURA® RID 2.1L has also been used for the <a target="_blank" rel="noopener noreferrer" href="https://labrulez.com/pdf/VFD_0194_d497a35278.pdf">simultaneous determination of sugars and organic acids in wine</a>, an application explored further in the article <a target="_blank" rel="noopener noreferrer" href="https://www.knauer.net/blog/blog-9/the-hidden-science-in-your-glass-147">“The hidden science in your glass”</a>.</li><li>Polymer and macromolecule characterization in GPC/SEC applications, for example when determining molecular-weight distributions. Examples include <a target="_blank" rel="noopener noreferrer" href="https://labrulez.com/pdf/4czsecf32d70a6d2yugpojtljg8rvp4vd4ur_05660bfad3.pdf">optimization of molecular-weight determination with the KNAUER AZURA® GPC/SEC system</a> and <a target="_blank" rel="noopener noreferrer" href="https://labrulez.com/pdf/qpwsk0igeqca8b5bqunbjjqnwum09tucb83s_cc4dbbcec9.pdf">analysis of mucin proteins using an AZURA® SEC System</a>.</li><li>Bioprocessing, including monitoring fermentation products such as <a target="_blank" rel="noopener noreferrer" href="https://labrulez.com/pdf/VBS_0079_Characterization_of_fructans_in_fermentation_products_with_sec_bc8f294f0e.pdf">fructans</a>.</li><li>Pharmaceutical applications, for example analysis of excipients such as sugars and polyols, as well as identity and purity testing of APIs. Dextranes, which are used as carrier materials in pharmaceuticals and as thickening or moisturizing agents in cosmetics, can be <a target="_blank" rel="noopener noreferrer" href="https://labrulez.com/pdf/h2oikq51kfvn6ebxij6hs88pxupstfgdqfyd_3e4f29d933.pdf">characterized by SEC</a>, as their properties depend strongly on molecular-weight distribution.</li><li>Lipid and surfactant analysis for formulation development and quality control.</li><li>Environmental analysis, including determination of selected organic and inorganic impurities in water samples.</li></ul>Overall, RI detection works best for analytes that are soluble, stable in solution, and compatible with straightforward isocratic separation conditions.It is not the preferred solution for trace analysis, gradient chromatography, or workflows requiring direct MS coupling. Nevertheless, it remains a practical and dependable option for compounds that are difficult or impossible to monitor using UV or fluorescence detection.<h4>Final Thoughts: A Detector That Still Deserves Attention</h4>As analytical laboratories adopt increasingly sophisticated detection technologies, refractive index detection can appear relatively simple. Yet for many applications, that simplicity is exactly its strength.For analytes such as sugars, alcohols, polymers, and other compounds without strong UV absorption, RID offers a direct, reliable, and non-destructive method of detection.Its greatest challenges are its sensitivity to temperature and its incompatibility with gradient elution. Under carefully controlled isocratic conditions, however, RI detection remains a dependable workhorse for routine HPLC and GPC/SEC applications.<blockquote>Pro tip: If your analyte seems invisible to conventional optical detection, a change of perspective may be all that is needed. RI detection could make it visible.</blockquote>In the next article in the “Seeing is Believing – Detection Made Easy” series, we will focus on Fluorescence Detection (FLD), a highly selective and sensitive technique for compounds that fluoresce naturally or can be derivatized to do so.

Seeing is Believing – Detection Made Easy Part 4: Refractive Index Detector

News from LabRulezLCMS Library - Week 36, 2026

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Based in Berlin, KNAUER is a medium-sized, owner-managed company that has been serving the sciences since 1962. We develop and manufacture scientific instruments of superior quality for liquid chromatography, including: Analytical HPLC/UHPLC, Preparative HPLC, Fast protein liquid chromatography (FPLC), Multi-column chromatography/Simulated moving bed (SMB) chromatography. High pressure dosing, in-line detection systems, and osmometry are additional business areas.

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ISTRAN EcaFlow Model 150 GLP automatic laboratory analyser

EcaFlow Model 150 GLP is a PC controlled automatic laboratory analyser for the determination of trace and high concentrations of metals, semi-metals and numerous nonmetals in various samples.

EcaFlow Model 150 GLP is a PC controlled automatic laboratory analyser for the determination of trace and high concentrations of metals, semi-metals and numerous nonmetals in various samples. By making use of the autosampler AS-150 up to 42 samples can be analysed in full automatic mode. The system supports the standardless, calibration curve and standard additions techniques. Over 70 validated applications are available for numerous sample types such as waters, foods, industrial liquids, wastes, etc. EcaFlow is a compact laboratory instrument controlled by a PC.<figure class="image"><img style="aspect-ratio:675/449;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_Eca_Flow_150_GLP_4_26c42795eb.jpg" alt="ISTRAN EcaFlow 150 GLP" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_Eca_Flow_150_GLP_4_26c42795eb.jpg 235w," sizes="100vw" width="675" height="449"></figure>The control unit contains the power support unit, control processor with a channel analyser, fast A/D and D/A converters and a high performance generic potentiostat/galvanostat. The compact flow system is controlled by the control unit and operates full automatically. It contains computer controlled electromagnetic valves for switching either to the sample solution or to an electrolyte solution or to a standard solution for the standard addition. Solutions are driven by a peristaltic pump. The heart of the system is the patented compact electrochemical cell.&nbsp;The cell uses disposable flow-through working electrodes made of suitable inert material. The counter and reference electrodes are separated from the flowing solutions hydrodynamically, so the reaction products at the counter electrode cannot interfere at the working electrode. The working electrode can be easily changed simply by loosening a screw. The cell is fixed to the panel of the instrument by a special connector which serves as an electrical contact to the electrodes. The connections of the tubes are made of Luer-type fitting, which facilitates fast manipulation when the electrode or cell is changed.<figure class="image"><img style="aspect-ratio:675/449;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_Eca_Flow_150_GLP_5_ac69cdfecf.jpg" alt="ISTRAN EcaFlow 150 GLP" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_Eca_Flow_150_GLP_5_ac69cdfecf.jpg 235w," sizes="100vw" width="675" height="449"></figure><h4>Technical data</h4>Potentiostat/galvanostat: 12 V / 20 mA Measuring cell: EcaCell 353c or EcaCell 104 with three electrodes Flow system: Full computer control with peristaltic pumping Weight: 7 kg Dimensions: 500 x 450 x 140 mm Software: Chronopotentiometry, coulometry, voltammetry Computer (option): Any PC with Windows XP and higher Autosampler (option): 42 positions + blank + standard<figure class="image"><img style="aspect-ratio:675/449;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_Eca_Flow_150_GLP_3_f4b61911c2.jpg" alt="ISTRAN EcaFlow 150 GLP" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_Eca_Flow_150_GLP_3_f4b61911c2.jpg 235w," sizes="100vw" width="675" height="449"></figure><h4>Available applications (all included):</h4><ol><li>Flow-through analyser test&nbsp;&nbsp;</li><li>Simultaneous determination of Cd, Pb and C&nbsp;</li><li>Determination of Pb&nbsp;</li><li>Simultaneous determination of Sn and Pb&nbsp;</li><li>Simultaneous determination of Pb, Cd and Hg&nbsp;</li><li>Determination of EDTA&nbsp;</li><li>Simultaneous determination of Zn, Cd, Pb, and Cu&nbsp;</li><li>Simultaneous determination of Cd, Pb, a Cu in wines&nbsp;</li><li>Determination of Ag&nbsp;</li><li>Determination of As(III) and total As in urine&nbsp;</li><li>Determination of As(III) and total As in fertilisers&nbsp;</li><li>Determination of Se in waters&nbsp;</li><li>Determination of Mn&nbsp;</li><li>Determination of Hg&nbsp;</li><li>Determination of Fe in waters&nbsp;</li><li>Determination of Sn&nbsp;</li><li>Determination of Bi&nbsp;</li><li>Determination of As in drugs&nbsp;</li><li>Determination of chlorides in waters&nbsp;</li><li>Simultaneous determination of Zn, Cd, Pb, and Cu in wines&nbsp;</li><li>Simultaneous determination of Zn, Cd, Pb, and Cu in spirits&nbsp;</li><li>Simultaneous determination of Cd, Pb, and Cu in beers&nbsp;</li><li>Determination of Fe (higher concentrations) in waters&nbsp;</li><li>Determination of Cd, Pb, and Cu in soil extracts&nbsp;</li><li>Determination of Sb&nbsp;</li><li>Simultaneous determination of Zn, Cd, Pb, and Cu in waters&nbsp;</li><li>Determination of As(III) and total As in waters&nbsp;</li><li>Determination of Zn, Cd, Pb, and Cu in pectines&nbsp;</li><li>Determination of iodides in urine&nbsp;</li><li>Determination of Au in water samples&nbsp;</li><li>Determination of low Ni contents&nbsp;</li><li>Determination of iodides in foods and beverages&nbsp;</li><li>Determination of Cr(VI) and total Cr in waters&nbsp;</li><li>Determination of nitrates in waters&nbsp;</li><li>Determination of Ascorbic Acid&nbsp;</li><li>Determination of chlorites in waters&nbsp;</li><li>Determination of bromates in waters&nbsp;</li><li>Boric acid in nickel plating baths&nbsp;</li><li>Determination of total As in waters&nbsp;</li><li>Acidimetry determination of strong and weak acids&nbsp;</li><li>Determination of Fe in concentrated sulphuric acid&nbsp;</li><li>Determination of Cu in waste waters&nbsp;</li><li>Alkalimetry determination of strong bases&nbsp;</li><li>Simultaneous determination of total As and Hg&nbsp;</li><li>Determination of Zn in galvanic baths&nbsp;</li><li>Determination of Ni in galvanic baths&nbsp;</li><li>Chlorides in galvanic baths&nbsp;</li><li>Cr(III) in passivating galvanic baths&nbsp;</li><li>Determination of phosphates with microporous electrodes&nbsp;</li><li>Determination of sub-ppb Hg concentrations&nbsp;</li><li>Determination of Zn in waste waters&nbsp;</li><li>Cu in wine samples&nbsp;</li><li>Determination of Fe in clear and turbid water samples&nbsp;</li><li>Determination of Au in ores&nbsp;</li><li>Determination of Sb in the presence of As and Cu&nbsp;</li><li>Determination of low Se concentrations&nbsp;</li><li>Sulphites in wines&nbsp;</li><li>Sulphites in beers&nbsp;</li><li>Titanium in TiO2&nbsp;</li><li>Determination of phosphates in clear as well as turbid water samples&nbsp;</li><li>Determination of total ammonia in underground and tap waters&nbsp;</li><li>Determination of total ammonia in waste waters&nbsp;</li><li>Determination of Cr(VI) in clear as well as turbid water samples&nbsp;</li><li>Determination of Ni in clear as well as turbid water samples&nbsp;</li><li>Determination of sulphides (S2-) in waste waters&nbsp;</li><li>Simultaneous determination of Zn, Cd, Pb, and Cu in turbid samples&nbsp;</li><li>Coulometric determination of sulphides in waters&nbsp;</li><li>Acid content in wines&nbsp;</li><li>Ethanol in beverages&nbsp;</li><li>Sulphites (SO3-) in foods&nbsp;</li><li>Chlorides (Cl-) in foods&nbsp;</li><li>Chlorites (ClO2-) in disinfected water&nbsp;</li><li>Manganese (Mn) in aquatic samples&nbsp;</li><li>Bromides (Br-) in water&nbsp;</li><li>Cd, Pb and Cu in concentrated zinc sulphate&nbsp;</li><li>Simultaneous determination of Pb, Cu and Hg in water</li></ol>

ISTRAN PCA2 Portable coulometric analyser

The new Portable Coulometric Analyser PCA is designed for laboratory and field analysis of heavy metals, semi-metals and numerous non-metals in aquatic solutions for a broad concentration range addressing contents from sub-μg/L up to several g/L.

The new Portable Coulometric Analyser PCA is designed for laboratory and field analysis of heavy metals, semi-metals and numerous non-metals in aquatic solutions for a broad concentration range addressing contents from sub-μg/L up to several g/L. In battery operation mode it is well suited for field applications. The analysis is full automatic, the sample solution is transported to the electrochemical measuring cell by means of a small but robust peristaltic pump and on completing the analysis the result is displayed and stored in the memory. The human interface is a simple touch screen.<h3>APPLICATION FIELDS</h3><ul><li>Drinking water</li><li>Surface water</li><li>Waste water</li><li>Foods and beverages</li><li>Biological samples</li></ul><figure class="image"><img style="aspect-ratio:1116/324;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_PCA_2_Portable_coulometric_analyser_aae89cc7dc.jpg" alt="ISTRAN PCA2 Portable coulometric analyser" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_PCA_2_Portable_coulometric_analyser_aae89cc7dc.jpg 245w," sizes="100vw" width="1116" height="324"></figure><h3>UNIQUE FEATURES</h3><ul><li>Metals, semi-metals, non-metals</li><li>Robust portable design</li><li>Full automatic analysis</li><li>At least 12 hours on battery operation ideal for field applications</li><li>Simple and fast operation</li><li>Ready to use applications</li><li>Broad concentration range, starting at sub-μg/L</li><li>Also suitable for coloured and turbid samples</li></ul><h3>TYPICAL APPLICATIONS INCLUDE</h3><ul><li>Arsenic, antimony, tin and selenium in various water samples</li><li>Heavy metals such as mercury, thallium, cadmium, indium, lead, bismuth, silver, gold.</li><li>Manganese, iron, cobalt, nickel, copper, zinc, gallium in various water samples</li><li>Chromium(VI) and total chromium</li><li>Iron(II), iron(III), total iron</li><li>Arsenic(III) and total arsenic</li><li>C-vitamin in vegetables, fruits, beverages, foods</li><li>Fluoride, chloride, bromide, iodide in waters and biological samples</li><li>Disinfection reagents such as chlorine, chlorine dioxide, hypochlorite in drinking water</li><li>Disinfection by-products such as chlorite, bromate in drinking water</li><li>Sulphite in foods, wines and beers</li><li>Sulphides in waste waters</li><li>Ammonia, hydrazine, nitrite, nitrate, cyanide in aquatic samples</li><li>Phosphate in waste waters</li><li>Ethanol in beverages</li><li>Methanol in waste water</li><li>Acids and bases in aquatic solutions, wines</li><li>Samples with suspended particles and solid samples can be analysed after an appropriate sample digestion, e.g. thermal, UV or microwave-assisted sample digestion.</li></ul>Ag, Ammonia, As, Bromate, Bromide, Cd, Chloride, Chlorite, Co, Cr(VI), Cu, EDTA, Fe, Hg, Iodide, Mn, Ni, Nitrite, Pb, Sb, Se, Sn, Sulphide, Tl, Zn<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Screenshot_2025_03_21_at_12_33_28_Istran_2_2d3350cbc8.jpg" alt="ISTRAN PCA2 Portable coulometric analyser" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Screenshot_2025_03_21_at_12_33_28_Istran_2_2d3350cbc8.jpg 245w," sizes="100vw" width="1116" height="326"><h3>ANALYSIS PRINCIPLE</h3>The analysis is based on automatic flow-through coulometry and voltammetry making use of a unique robust electrochemical measuring cell with a maintenance-free built-in reference and auxiliary electrodes and a long-life disposable working electrode. The sample solution is pumped into the cell where the determined species (analyte) is measured through its electrochemical conversion, i.e. it is electrochemically oxidised or reduced at the electrode surface. Low concentrations are determined after a preliminary electrochemical deposition of the measured species at the electrode surface (enrichment step), then the deposit is stripped by constant current while the signal is recorded and evaluated. In such a way, concentrations in the sub- μg/L level can be easily measured. A typical response of copper displayed on the touchscreen is depicted below.<figure class="image"><img style="aspect-ratio:1116/326;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_PCA_2_Portable_coulometric_analyser_3_d630e0cd53.jpg" alt="ISTRAN PCA2 Portable coulometric analyser: A typical response of copper displayed on the touchscreen" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_PCA_2_Portable_coulometric_analyser_3_d630e0cd53.jpg 245w," sizes="100vw" width="1116" height="326"></figure><h4>The analytical procedure consists of three main steps:</h4><ol><li>Sample preparation. It includes the filtration of the sample (when necessary) and addition of a reagent to the sample. Solid samples or samples with suspended particles require a sample digestion..</li><li>Analysis. Full automatic procedure yielding the result displayed on the touch screen. The analysis starts on immersing the sampling tube into the sample which is pumped through the measuring cell where the analyte is electrochemically measured. Usually multiple runs are done with measurements repeated and evaluated automatically.</li><li>Cleaning. On completion of the analyses the cell is rinsed with water or a suitable reagent solution and the analyser is set to standby mode or turned down.</li></ol><h3>CONTROL AND COMMUNICATION</h3><ul><li>User interface: Powerful 4.3” Intelligent LCD-TFT display module. 480 x 272 Resolution, RGB 65K true to life colours, TFT Screen with integrated 4-wire Resistive Touch Panel. On-board micro-SD memory card connector for data logging purposes</li><li>User interface for uploading new measuring parameters, downloading results and curves</li><li>User interface with administrator access, firmware upgrading and calibration of electronic circuits</li></ul><h3>MECHANICAL AND ELECTRICAL DATA</h3><ul><li>Enclosure: The PCA instrument is integrated into a robust transport case made of polypropylene. Watertight, crushproof, and dustproof. Protection class IP 67</li><li>Dimensions (W x D x H): 27 x 24.6 x 12.4 cm (10.62” x 9.68” x 4.87”)</li><li>Weight: 2.9 kg (6.4 lbs)</li><li>Power input: 100-240V/50-60Hz&nbsp;</li><li>Battery: Ni-MH, 14.4V/4.5Ah</li><li>Ambient operating conditions: 5 °C – 45 °C at 5 - 95% relative humidity non-condensing (41 °F – 113 °F)</li></ul><h3>TECHNICAL SPECIFICATIONS</h3><h4>MEASUREMENT</h4><ul><li>Analysis method: Coulometry and voltammetry in chronopotentiometric mode</li><li>Determined species: Metals, semi-metals, non-metals, organics (refer to the up to date list of applications)</li><li>Measuring cell: robust three-electrode flow-through cell. Built-in maintenance-free platinum auxiliary and silver/silver chloride reference electrodes. Longlife disposable working electrodes made of glassy carbon, gold, silver, platinum, copper. No mercury or gold plating solutions required.</li><li>Detection limit: less than 1 μg/L *</li><li>Precision (RSD, under repeatability conditions): 5 % full scale for calibration or validation solutions</li><li>Calibration: A built-in 10 point calibration curve adjusted in the factory</li><li>Re-calibration: Two point re-calibration (blank and calibration solution) carried out on demand</li><li>Measuring ranges: Please check the respective application list for each parameter</li><li>Analysis time/run: 1-10 min, depending on the analyte concentration *.</li></ul>*Refer to the corresponding application list<h4>DATA LOGGING AND SECURITY</h4><ul><li>Log files with over 1000 results and corresponding curves are stored</li><li>Easy export to spreadsheet files</li></ul><h4>GLP FEATURES</h4><ul><li>Automatic storage of about 1000 results, including the corresponding signal curve, date, time of analysis and the sample identifier.</li><li>Statistical evaluation of the results</li><li>Checking the accuracy and precision by means of a control sample with known analyte concentration.</li></ul><figure class="image"><img style="aspect-ratio:1116/326;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_PCA_2_Portable_coulometric_analyser_4_6b3bf1dde1.jpg" alt="ISTRAN PCA2 Portable coulometric analyser " srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_PCA_2_Portable_coulometric_analyser_4_6b3bf1dde1.jpg 245w," sizes="100vw" width="1116" height="326"></figure><h4>REAGENTS AND CONSUMABLES</h4><ul><li>Reagents, consumables, containers and tools can be transported in a separate transport case</li><li>Reagent consumption is low, usually 0.1 to 1 mL/sample</li><li>No organic or toxic reagents are used</li><li>All reagents and consumables are delivered by the producer</li><li>Reagent formulas are available against royalties</li><li>Cleaning solution: Demineralised water or in most cases tap water is sufficient</li><li>Calibration or validation solution: Available from the producer, prepared from single element Certified Reference Materials</li></ul><h4>OPTIONS</h4><ul><li>Additional applications each including a measurement parameter file, measuring cell (if needed), electrode</li><li>Transport case for reagents, consumables, tools ideal for field operation</li></ul>

ISTRAN EcaLayer Metal Layer Analyser

The coulometric method ensures accurate and precise results. The analyser is extremely simple to use and therefore it is also suitable for routine measurements not needing any special qualification.

The coulometric technique is used for measuring the thickness of electroplated deposits on a wide variety of substrates such as steel, aluminium, copper, nickel, silver, alloys, some insulators.The coulometric method ensures accurate and precise results. The analyser is extremely simple to use and therefore it is also suitable for routine measurements not needing any special qualification. Moreover, coulometry is the only method allowing the measurement of multi-layer coatings such as chrome, chrome oxide on tin, tin, tin-iron intermetals on steel, etc.<h3>Measuring principle</h3>The fundamental principle is the Faraday’s Law. The method is similar to the electrolytic plating process but here the coating is removed electrochemically from a defined surface area. For this purpose, a piece of the sample is placed to the flow-through measuring cell which is filled with a suitable electrolyte solution and the analysed metal coating is subsequently removed by applying an appropriate current. Hence, metal layers are measured by anodic dissolution, metal oxide layers, such as tin oxide on a tin coating, are measured by cathodic dissolution. The measured sample area is given by the gasket used and it can include 0.2 to 20 cm2. The analysis is performed totally automatically and is controlled by a PC.By applying the Faraday’s Laws, the thickness of a metal layer can be calculated.<h3>The EcaLayer Model 220/220a consists of three major parts:</h3><figure class="image"><img style="aspect-ratio:643/961;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_Eca_Layer_Metal_Layer_Analyser_4_ab4b7f6aff.jpg" alt="ISTRAN EcaLayer Metal Layer Analyser - Scheme" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_Eca_Layer_Metal_Layer_Analyser_4_ab4b7f6aff.jpg 104w," sizes="100vw" width="643" height="961"></figure><h4>1. Analytical Unit</h4><h5>Two types of analytical units can be used:</h5><ul><li>Module A for metal coatings and metal oxide layer measurements needing the removal of dissolved oxygen, e.g. tin oxide measurements, and</li><li>Module B for measurements not needing oxygen removal, e.g. tin layer thickness measurements.</li></ul>Module A encloses a unique flow-through analytical cell with the sample as the working electrode, a stainless steel counter and Ag/AgCl reference electrodes, a peristaltic pump, an electromagnetic valve for the gas and a reservoir for the electrolyte solution.Module B is built in the same way but without the gas unit.<h4>2. Control Unit</h4>The control unit comprises a computer controlled potentiostat/galvanostat with a maximum output of 100 mA, 16-bit A/D and D/A converters. The unit is controlled by a microprocessor linked to the PC through a serial line.<h4>3. Computer and software</h4>Any IBM compatible PC can be coupled to the instrument. The user-friendly software facilitates the use without any special knowledge about electrochermistry. GLP facilities such as archiving, printing of reports, selftesting are included.<h3>Function</h3><h4>The metal layer analyser works as follows:</h4><ol><li>The sample is placed into the cell and the cell is closed. The next steps are performed automatically by computer control.</li><li>The cell is filled with the electrolyte from the reservoir. If needed, the electrolyte solution is with an inert gas to remove dissolved oxygen.</li><li>The coating is removed by applying a suitable constant current and the potential of the sample material (i.e. the working electrode) is monitored and registered in the time.</li><li>The electrolyte solution is removed from the cell.</li><li>In the meantime, the registered potential-time dependence is evaluated giving the dissolution time and the layer thickness is calculated automatically.</li><li>The cell is opened and the sample is removed. The whole procedure takes 4 to 8 minutes.</li></ol><h3>Some applications</h3><h5>Measurements of tin coatings on steel</h5>Tin coatings are measured by anodic dissolution in HCl electrolyte solution with currents up to 100 mA. Both the tin and the tin-iron intermetallic layers can be measured in a single run.<figure class="image"><img style="aspect-ratio:621/342;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_Eca_Layer_Metal_Layer_Analyser_0d2f857bae.jpg" alt="ISTRAN EcaLayer Metal Layer Analyser: Measurements of tin coatings on steel" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_Eca_Layer_Metal_Layer_Analyser_0d2f857bae.jpg 245w," sizes="100vw" width="621" height="342"></figure><h5>Measurement of passivating chromous layers on tin coated steel</h5>The chromium layers are dissolved by anodic oxidation in a phosphate buffer electrolyte solution with currents of few mA.<figure class="image"><img style="aspect-ratio:645/353;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_Eca_Layer_Metal_Layer_Analyser_2_31bc2b54d5.jpg" alt="ISTRAN EcaLayer Metal Layer Analyser: Measurement of passivating chromous layers on tin coated steel" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_Eca_Layer_Metal_Layer_Analyser_2_31bc2b54d5.jpg 245w," sizes="100vw" width="645" height="353"></figure><h5>Measurement of oxide layers on tin coatings</h5>Oxide layers can be determined by cathodic dissolution in deairated HBr electrolyte solution with currents about -1 mA. Due to the uncertain stoichiometry of the oxide layers, the results are expressed as charge consumed per sample area.<figure class="image"><img style="aspect-ratio:685/348;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_Eca_Layer_Metal_Layer_Analyser_3_0b111ab468.jpg" alt="ISTRAN EcaLayer Metal Layer Analyser: Measurement of oxide layers on tin coatings" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_Eca_Layer_Metal_Layer_Analyser_3_0b111ab468.jpg 245w," sizes="100vw" width="685" height="348"></figure><h3>Ordering information</h3><h5>EcaLayer Model 220 includes</h5><ul><li>Control Unit</li><li>Flow System with Module A</li><li>Application software</li><li>PC with printer (specified by the customer)</li><li>All necessary cables</li><li>Users manual</li><li>Methodologies according to EN ISO 2177</li></ul><h5>EcaLayer Model 220a includes</h5><ul><li>Control Unit</li><li>Flow System with Module B</li><li>Application software</li><li>PC with printer (specified by the customer)</li><li>All necessary cables</li><li>Users manual</li><li>Methodologies according to EN ISO 2177</li></ul>

Products from category Electroanalytical methods - page 1

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