Application Notes: General

The utility of the Thermo Scientific™ TRACE™ 1610 GC system and the Thermo Scientific™ TSQ™ 9610 triple quadrupole GC-MS/MS for the analysis of ethylene oxide and 2-chloroethanol residues in food

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This high-throughput proteome profiling approach provides deeper proteome coverage with preserved biological information. The ENRICH-iST technology enables the analysis of previously undetected low- abundance proteins, facilitating the discovery of additional potential biomarkers.

Labile post-translational modifications are better preserved using ECD than conventional MS fragmentation techniques such as collision-induced dissociation (CID). Common modifications, such as glycosylation and phosphorylation, can impact the safety, efficacy, and binding activity of monoclonal antibodies but are challenging to identify. Stephen Sciuto from Agilent Technologies and colleagues analyzed tryptic digests of NIST mAb and Infliximab using an 6545XT Q-TOF mass spectrometer in ExD or CID mode. ECD provided higher sequence coverage than CID, reaching 100% for glycosylated peptides in Infliximab. The ability to pinpoint glycosylation sites using fragment ions demonstrates the power of ECD for characterizing glycopeptides.

Designed initially to expedite proteomic sample preparation, the BeatBox now emerges as a pivotal instrument for metabolomic and lipidomic sample preparation. Its highly efficient extraction of polar metabolites and non-polar lipids from tissues aids the processing of limited specimens, ideal for targeted MS approaches.

The first reported combination of microdroplet reactions with ECD fragmentation offers a quicker way to analyze monoclonal antibodies for disease treatments. Thomas Walker from Agilent Technologies and co-workers demonstrate the use of an Agilent Jet Stream electrospray ionization source to facilitate in-spray chemical reduction and protease digestion of monoclonal antibodies. Downstream fragmentation of the microdroplet reaction products with ECD provided rapid characterization of intact antibodies in minutes. Efficient ECD fragmentation yielded rich sequence information including evidence of disulfide bond connectivity and confirmation of key sequences called complementary determining regions. These results highlight this method’s potential for fast and cost-effective antibody characterization with minimal sample preparation.

ENRICH-iST effectively addresses the challenge of high diluted protein content and high dynamic abundance range, which is typical for CSF samples. By improving the detection of low-abundance proteins, ENRICH-iST is a powerful tool for advancing the discovery of new protein biomarkers in CSF proteomic studies.

In this study, we present an ion-pairing-free method for AXPs analysis using microchip CE-MS. This fast, simple method achieves baseline resolution for Adenosine, AMP, ADP, and ATP. Excellent linearity and sensitivity are observed in human plasma.

The Charge Variant Analysis (CVA) kit offers superior performance over our first-generation Intact Antibodies kit. With the CVA kit, users can expect greater peak resolution and the ability to properly analyze proteins in their fully native states.

The traditional method for HPLC gradient validation uses a UV detector which has documented limitations. An improved approach using non-invasive flowmeters is described.

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