In German, there is a well-known saying: “Der April macht, was er will!” — loosely translated as “April does whatever it wants.” While this usually refers to unpredictable weather, it can sometimes describe other situations just as well.As an analytical application specialist at KNAUER, I was genuinely excited when, at the end of 2023, my colleague and product manager Mareike Myrach and I were assigned the project of the <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1454">Liquid Handler LH 8.1</a>. At that time, we had no prior hands-on experience with the system, but we quickly got up to speed — largely because learning by doing turned out to be surprisingly intuitive.Following an intensive phase of testing, method development, and optimization, the Liquid Handler LH 8.1 was officially introduced by KNAUER in April 2025. Returning to the April proverb — this time, April behaved quite differently. Rather than being unpredictable, everything came together smoothly (even if not weather-wise!). All documentation was finalized, product configurations defined, and specifications locked in. It was a very satisfying milestone.&nbsp;<h3>What makes the Liquid Handler LH 8.1 stand out?</h3>Let’s take a closer look at some of its key features.<h4>Flexible configuration tailored to your workflow</h4>The KNAUER LH 8.1 is a highly customizable XYZ autosampler designed to adapt to a wide range of laboratory requirements. It supports numerous modules and accessories, allowing users to build a system that fits their specific applications.Core components include the injection valve, the Robotic Cooler, and the fast wash station — all essential for efficient operation. Beyond these, we are continuously exploring additional enhancements.&nbsp;For example, how about seasonal upgrade kits?<ul><li>LH 8.1 Easter edition</li><li>LH 8.1 Christmas edition</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Fig_1_Left_LH_8_1_Upgrade_Kit_7b9a711bab.jpg" alt="KNAUER: Fig. 1: Left: LH 8.1 Upgrade Kit “Easter”, right: LH 8.1 Upgrade Kit “Christmas” (limited availability — only 1 in stock!)" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Fig_1_Left_LH_8_1_Upgrade_Kit_7b9a711bab.jpg 234w," sizes="100vw" width="1263" height="843"><h4>Flexible sample storage and high-throughput capability</h4>For laboratories focused on high-throughput analysis, the Robotic Cooler module is indispensable. Each unit can accommodate up to three sample racks, with 130 vials per rack — totaling 390 vials per module.Depending on the rail length, multiple Robotic Coolers can be installed and operated independently. On the longest rail configuration, up to three modules can be used simultaneously, increasing the total capacity of a single LH 8.1 system to as many as 1,170 vials (1.5 mL each).Naturally, the system is not limited to standard vials. It can store a variety of sample types within a temperature range of 4–40 °C.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Fig_2_Left_Tray_with_common_samples_middle_tray_with_special_samples_right_very_very_special_samples_b1d2e3daea.jpg" alt="KNAUER: Fig. 2: Left: tray with standard samples, middle: tray with specialized samples, right: very special samples" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Fig_2_Left_Tray_with_common_samples_middle_tray_with_special_samples_right_very_very_special_samples_b1d2e3daea.jpg 245w," sizes="100vw" width="1176" height="402"><h4>True zero sample loss</h4>Have you ever encountered the concept of “sandwich injections” in liquid chromatography? It may sound unusual at first. Replace the bread with standard HPLC solvents and the filling with your sample, separated by small air gaps — and you have a liquid “sandwich.”The LH 8.1 takes this concept even further. It allows sampling from virtually any container type. Whether it’s a standard vial or something more unconventional — like a filled chocolate egg — the system can handle it. The result? A rather creative “egg sandwich.”<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Fig_3_Left_Exemplary_sandwich_build_up_right_aspiration_from_double_coated_chocolate_sample_container_8e9f9fa243.jpg" alt="KNAUER: Fig. 3: Left: example of sandwich configuration, right: aspiration from a chocolate-based sample container" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Fig_3_Left_Exemplary_sandwich_build_up_right_aspiration_from_double_coated_chocolate_sample_container_8e9f9fa243.jpg 245w," sizes="100vw" width="1218" height="751"><blockquote>Please note: using such unconventional containers may significantly increase both carryover and... enjoyment.</blockquote><h4>Carryover and injection precision</h4>When evaluating HPLC injectors, injection precision is one of the most critical parameters. After optimizing the injection conditions, we achieved excellent performance.To ensure ease of use, all optimized parameters have been integrated into the software drivers. This allows users to benefit from high precision without complex programming.<h5>Injection precision (RSD):</h5><ul><li>Full loop injection: ≤ 0.10%</li><li>Sandwich injection (&gt;5 µL): ≤ 0.15%</li></ul>Another key parameter is sample carryover, evaluated using recommended washing protocols. During testing, we measured carryover using chlorhexidine as a standard compound to allow comparison with other autosamplers. Additionally, caffeine was tested due to its widespread use and accessibility in laboratories.Taking advantage of the LH 8.1’s flexibility, we also explored sampling from unconventional containers.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Fig_4_Exemplary_sample_take_up_for_the_determination_of_carry_over_47706172c7.jpg" alt="KNAUER: Fig. 4: Left: injection of diluted caffeine sample for quantification, right: injection of concentrated sample for carryover assessment" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Fig_4_Exemplary_sample_take_up_for_the_determination_of_carry_over_47706172c7.jpg 224w," sizes="100vw" width="1248" height="870"><h5>Measured carryover values:</h5><ul><li>Chlorhexidine: &lt; 0.005%</li><li>Caffeine: &lt; 0.002%</li></ul>Returning to the beginning of this article — you may have noticed that not only “April does whatever it wants,” but sometimes KNAUER blog authors do as well.Despite the seasonal theme, we hope you discovered a few hidden “Easter eggs” throughout the text — and didn’t take everything too seriously.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Fig_5_KNAUER_blog_authors_72de1a0c72.jpg" alt="KNAUER: Fig. 5: KNAUER blog authors" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Fig_5_KNAUER_blog_authors_72de1a0c72.jpg 237w," sizes="100vw" width="1150" height="757"><blockquote><ul><li>More reputable information: <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1454">KNAUER Liquid Handler LH 8.1</a></li></ul></blockquote>

Seasonal update on liquid handling

News from LabRulezLCMS Library - Week 17, 2026

<h4>Let’s begin with a simple question: what do we actually mean by high throughput?</h4>In the laboratory, high throughput usually refers to the ability to analyze tens, hundreds, or even thousands of samples per day, either across a laboratory workflow or on a single analytical system. Achieving this requires more than just a fast method. It depends on reliable instrumentation, automation, sufficient sample capacity, and smart system design that minimizes idle time between runs.In this article, we look at the key requirements for high-throughput HPLC analysis and how they are addressed in the <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/2371">HTQC system</a>.<h4>Speed</h4>High-throughput HPLC workflows typically rely on short methods. This includes both the chromatographic runtime and the cycle time of the injection module.With the HTQC system, fast gradient applications up to 1200 bar can be implemented using two integrated UHPLC high-pressure gradient pumps.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Fig_1_2_HPG_pumps_of_HTQC_system_left_P_8_1_L_max_pressure_1240_bar_right_P_6_1_L_max_pressure_1000_bar_4d4873ff2f.jpg" alt="KNAUER: Fig. 1–2 HPG pumps of HTQC system, left: P 8.1L (max. pressure 1240 bar), right: P 6.1L (max. pressure 1000 bar)" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Fig_1_2_HPG_pumps_of_HTQC_system_left_P_8_1_L_max_pressure_1240_bar_right_P_6_1_L_max_pressure_1000_bar_4d4873ff2f.jpg 245w," sizes="100vw" width="1266" height="386">We will not discuss the full details of transferring classical HPLC methods to fast, high-resolution UHPLC methods here, but UHPLC implementation can dramatically reduce total analysis time.Let’s use a hypothetical example. Imagine Giorgia, a randomly chosen name, working in pharmaceutical quality control in 1998. She must have travelled back in time, because she would have been too young to work in a lab then, but the example still works. With a classical HPLC method, each sample takes approximately 75 minutes, including equilibration, analysis, and backflushing of a 250 × 4.6 mm ID column. This type of method has been common in QC laboratories around the world. During an eight-hour working day, Giorgia can analyze around six samples.Now let’s transfer the same method to UHPLC. The improvement is substantial. Analysis time, equilibration time, and backflushing time are all reduced to under six minutes per sample. Giorgia can now process around 90 samples in one working day.You may wonder why the HTQC system requires two UHPLC gradient pumps. We will come back to that shortly.The next way to increase speed is to reduce injector cycle time. Injection procedures and washing steps can sometimes take a significant amount of time. This is where the LH 8.1 liquid handler becomes important.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Fig_3_KNAUER_LH_8_1_Liquid_Handler_77ab506ca6.webp" alt="KNAUER: Fig. 3 KNAUER LH 8.1 Liquid Handler" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Fig_3_KNAUER_LH_8_1_Liquid_Handler_77ab506ca6.webp 129w," sizes="100vw" width="800" height="971">The LH 8.1 supports overlapped injections. This means that the next injection can already be prepared while the current analysis is still running. Necessary cleaning steps of the injection system are still maintained, but idle time is reduced.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Fig_4_Schematic_buildup_of_injections_with_and_without_overlapped_injections_af089ba652.webp" alt="KNAUER: Fig. 4 Schematic buildup of injections with and without overlapped injections" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Fig_4_Schematic_buildup_of_injections_with_and_without_overlapped_injections_af089ba652.webp 245w," sizes="100vw" width="1920" height="452">Let’s return to Giorgia. By using overlapped injections in her QC method, she saves about one minute per sample. This increases her capacity to approximately 105 samples per day.<h4>Sample Throughput</h4>A high-throughput system must also be able to handle and store a sufficient number of samples. Here, the LH 8.1 provides another major advantage. In the long-rail version, it can be equipped with up to three robotic coolers.With three coolers, each containing three drawers, the system can hold nine 10 × 13 sample trays. That means a total capacity of 1170 vials. The samples are also temperature controlled.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Fig_5_6_Robotic_Cooler_with_two_10x6_trays_LH_8_1_887_version_with_two_Robotic_Coolers_855b10c2a3.jpg" alt="KNAUER: Fig. 5–6 Robotic Cooler with two 10x6 trays, LH 8.1 (887 version) with two Robotic Coolers" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Fig_5_6_Robotic_Cooler_with_two_10x6_trays_LH_8_1_887_version_with_two_Robotic_Coolers_855b10c2a3.jpg 245w," sizes="100vw" width="1262" height="503">Combined with the low eluent consumption typical of UHPLC, this large sample capacity makes it possible to extend operation from an eight-hour workday to 24-hour operation.For Giorgia and her QC lab, this changes everything again. The same UHPLC method, including overlapped injections, can now run continuously around the clock. This allows approximately 320 samples to be processed per day.Is that enough? Maybe not. As the blog title suggests: we just can’t get enough.<h4>Automation</h4>In addition to a standard 6-port, 2-position injection valve, the HTQC system includes an additional valve. This special column-switching and backflushing valve enables two columns to be operated alternately within a single UHPLC system.While one column is used for analysis, the second column can be backflushed and equilibrated in the reverse flow direction at the same time. This is particularly useful for reducing matrix effects, which are often encountered in QC laboratories when complex sample matrices are analyzed. It also helps reduce overall method runtime.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Fig_7_Exemplary_flow_scheme_of_special_column_switching_valve_d837a71117.webp" alt="KNAUER: Fig. 7 Exemplary flow scheme of special column switching valve" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Fig_7_Exemplary_flow_scheme_of_special_column_switching_valve_d837a71117.webp 127w," sizes="100vw" width="735" height="905"><h4>Parallel Processing</h4>Remember the earlier question: why does the system use two UHPLC gradient pumps?The reason is now clear. The second gradient pump is required to backflush one column while the other column is connected to the analytical flow path through the special switching valve.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Fig_8_Schematic_illustration_of_column_cleaning_equilibration_and_analysis_with_special_backflush_valve_eae2e6f705.webp" alt="KNAUER: Fig. 8 Schematic illustration of column cleaning, equilibration and analysis with special backflush valve" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Fig_8_Schematic_illustration_of_column_cleaning_equilibration_and_analysis_with_special_backflush_valve_eae2e6f705.webp 245w," sizes="100vw" width="1920" height="281">Giorgia immediately ordered a second UHPLC pump and the special valve for her QC lab. She now has a complete HTQC system and is very pleased with the result.Why? Let’s calculate it one final time. With all automation features in place, Giorgia can clean one column while the other column analyzes a sample. This enables her to process an impressive 600 samples per day.Compared with the classical HPLC method she used in 1998, the daily sample throughput has increased from six samples to 600 samples. That is a 100-fold increase.<h4>Summary</h4>We started with a question, so let’s end with one too: what steps increased the throughput?First, the method was scaled down from classical HPLC to a fast UHPLC approach. Then, a second pump and a special column-switching and backflushing valve were added to the UHPLC setup. Together with the <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1454">LH 8.1 liquid handler</a> and its exceptional sample capacity, the HTQC system becomes a flexible and powerful configuration for high-throughput analysis.The system can also be coupled to nearly any detector used in HPLC. Because of its ability to operate at very high speed, it is especially well suited for mass spectrometric methods.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Fig_9_Complete_flow_scheme_of_HTQC_system_with_highlighted_system_components_edef36cb42.webp" alt="KNAUER: Fig. 9 Complete flow scheme of HTQC system with highlighted system components" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Fig_9_Complete_flow_scheme_of_HTQC_system_with_highlighted_system_components_edef36cb42.webp 161w," sizes="100vw" width="800" height="775"><blockquote>For further information on this topic, please contact our authors: kramer@knauer.net, m.myrach@knauer.net</blockquote>

Introducing Our System Solution for High Throughput Quality Control – HTQC

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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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