Application Notes: General

This brief communication highlights the assessment of Hamilton PRP-3 HPLC column attributes when analyzing biologically active peptides.

Charge heterogeneity is present in most biopharmaceutical protein products. During the manufacturing process, charge heterogeneity of the protein therapeutics can occur due to enzymatic cleavage and chemical post-translational modifications (PTM). For therapeutics like ADCs, not only the antibody contributes to the heterogeneity but also the linker and payload, which add even more complexity to the charge variant profiles. Characterizing the charge heterogeneity of ADCs is essential for critical quality attribute (CQA) assessment to ensure drug safety, efficacy, and potency.

Despite the utility of the essential oil mixture, it has been shown that allergies can arise from some of the individual components.

Plasticizers added to water bottles to add stability to the bottles can be unknowingly extracted in drinks leading to possible endocrine interactions.

For many years, Solid Phase Extraction (SPE) has been performed using plates and cartridges packed with a bed of loose media. Extracting samples of interest while removing contamination from samples presented to the chromatography system results in lower costs associated with detector maintenance and extends column lifespan. Cleaner samples also improve specificity in analysis and increase sensitivity. Traditional products, however, have inherent limitations in reproducibility of flow and recovery. The innovative composite technology found in the Microlute® range greatly improves flow consistency providing a step change in the reproducibility of processing and analyte recover.

Chromium can pose as a beneficial element or a poison, therefore it is imperative to identify contaminated waters, especially drinking water.

The Microlute® CSi products use a novel composite technology which uses a blend of porous plastic and chromatographic SPE resin. This technology has been designed to eliminate issues caused by inherent issues and inconsistent packing of loose packed SPE plates. The data in this application note compares SPE results from a C18 10 mg loose packed plate with a C18 10 mg composite plate (Microlute® CSi) which were both created using the same batch of C18 resin.

GRPC peptides are found in the entire body. Isolation of seven classic GRPC peptides initiating in the GI tract could implicate disease.

The isolation and identification of 5 common psychedelic compounds was performed using the alkaline ion-pairing agent hexylamine to facilitate excellent resolution.

This poster describes GenNext’s first-in-class instrument for fully automated protein footprinting that delivers highly precise and accurate quantification for numerous higher order structure (HOS) mapping experiments.

Restek is a global leader in PFAS analysis with advanced sample prep and analytical techniques. We’ve gathered feedback from labs around the world to offer the latest insights, applications, and tailored solutions on this resource page. Count on Restek as your partner in PFAS analysis. Have questions?

Poly- and perfluoroalkyl substances, or PFAS, are rapidly emerging as some of the most important environmental contaminants to monitor around the world. Their widespread use and environmental persistence make them truly a global issue. Concerns about possible health risks are driving environmental scientists to look for these compounds everywhere. However, one other concerning place where at least some of these compounds are present is inside the very instruments used for PFAS analysis of environmental samples. PFAS delay columns can be used to manage this type of contamination.

HPLC method development of structurally similar components is an arduous task to undertake. Understanding the principles of liquid chromatography and applying them in a structured, streamlined approach not only speeds up the method development process but also provides traceability for the activity in an easy-to-follow format. Having a structured protocol for method development also allows novice users to develop methods independently, without the oversight of expert chromatographers. This app note shows fast method development using a structured protocol called the systematic screening protocol. The protocol used to develop the method relies on MaxPeak™ High-Performance Surfaces (HPS) technology, featured in MaxPeak Premier Columns, to mitigate any non-specific adsorption (NSA) seen between the column and the analytes. Employing this column technology, along with the systematic screening protocol, a method was developed which provides good peak shape and complete separation of all eight dyes.

High efficiency columns increase resolution by reducing peak widths. This enables easier peak integration and identification, as the peaks of interest are better separated from each other and from potential background or excipient peaks. There are several ways for an analyst to improve separation efficiency; one being to use columns packed with smaller particle size stationary phases. Another way is to use longer columns. However, a drawback in the use of both options is that they can be limited by the system operating pressure. Another path forward is the use of solid-core or superficially porous particles (SPP), which have been proven to improve efficiency without sacrificing operating pressure. This app note shows incremental steps on how to improve separation efficiency for a mixture of three analytes.

HPLC method development is not without its challenges. What happens when your favorite column struggles to achieve your peak shape, sensitivity, or reproducibility goals? Whether you’re developing or transferring methods, quickly achieve consistent results with MaxPeak Premier Columns. Available from sub-2 µm to 5 µm HPLC particle sizes, fully porous and solid-core, you can choose the column configuration that meets your needs and eliminate doubt from your chromatographic separations. Find MaxPeak Premier app notes, videos and more at waters.com/tothemax.

Due to their ubiquitous occurrence in aquatic environments, measuring ultrashort-chain per- and polyfluoroalkyl substances (PFAS) in various source waters to monitor their presence and the potential for human exposure has become very important. However, with carbon chain lengths of less than C4, these small, highly polar compounds are difficult to analyze using standard PFAS tests that are based on reversed-phased liquid chromatography (RPLC). In this study, an accurate, reliable analytical LC-MS/MS method for PFAS in water was developed to specifically quantify C1 to C4 PFAS in both potable and non-potable sources. A direct injection workflow was implemented to simplify the testing process and to avoid potential contamination originating from poor sample preparation procedures.

A Survey of Existing PFAS Testing Methods and Guidelines from Around the World

Helium is running out, the worldwide demand is exceeding current production levels. Learn how Hydrogen could be your perfect replacement for Helium.

HPLC is a versatile and widely used method for analyzing various compounds, particularly in the pharmaceutical industry. It's preferred by generic pharmaceutical companies and quality control groups due to its accessibility compared to newer technologies like Ultra-Performance Liquid Chromatography (UPLC™). In recent years, there has been a growing emphasis on making analytical chemistry techniques, such as HPLC, more sustainable. These "green" initiatives aim to reduce the use of toxic reagents, minimize waste, and lower energy consumption, all while maintaining high scientific standards. This app note highlights Development of a new, greener HPLC method for rivaroxaban and impurities, aligned with the USP monograph and using the Analytical Method Greenness Score (AMGS).

High Performance Liquid Chromatography (HPLC) has been a staple in analytical laboratories for several years. The utility of this technique is such that it can be used to analyze a wide variety of analytes. HPLC allows a lower cost alternative compared to UHPLC instruments, which boast higher performance for the higher capital investment. HPLC systems are still used regularly in the pharmaceutical industry for QA and QC type work such as batch release testing and method development.

When scaling an established analytical method across columns packed with different particle sizes and different column configurations (internal diameters and lengths), the amount of time that is required outside of the lab to produce the equivalent method conditions is considerable. When dealing with a gradient method, the calculations required include determining the new flow rate, gradient times, and injection volume. An analyst can perform these calculations manually using the appropriate equations or tools like the Waters Columns Calculator. This app note examines two scaling workflows by first performing a theoretical scale-down experiment manually using the appropriate method scaling equations, and then repeating the experiment using the scaled-down conditions generated by the Waters Columns Calculator. Strong agreement between manual calculations and the results using the Waters Columns Calculator validate the Waters Column Calculator for its use in scaling methods effectively, with a significant improvement in time savings and a reduction in potential calculation errors and/or uncertainties.

Pro EZLC online tools make it easy to develop and optimize new LC methods or translate existing ones quickly and accurately. See the effects of parameter changes instantly at your desk without spending time in the lab or tying up an instrument. Take advantage of Restek’s years of chromatographic expertise at any time, from anywhere, with simple-to-use yet incredibly powerful EZLC method development tools.

To address the Helium shortage GC laboratories have begun looking at possible replacement gases and new approaches to help obtain the carrier gases needed to continue their work. One of the most promising options is using the use of gas generators to provide a steady supply of hydrogen gas as a replacement for helium. Although some concerns—and some myths—persist about using hydrogen, it offers multiple benefits and advantages over helium, notably particularly when a gas generator replaces high-pressure gas cylinders.

A Methods-Based Reference to Lab Supplies for PFAS Testing

Hydrogen is the perfect molecule for gas chromatography, especially for the replacement of the expensive Helium.

Discover the GC 2400™ Platform for analytical precision and robustness for fuel alcohol analysis over a wide range of sample concentrations.

Master Gas Chromatography Troubleshooting - Streamline Your Analysis with Expert Guidance.

Discover how the PerkinElmer GC 2400™ Platform provides fast analysis and high reproducibility.

Discover how the PerkinElmer GC 2400™ Platform helps with the residual solvent in plastic with accuracy and sensitivity, providing reliable and reproducible runs for high throughput laboratories.

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