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Click the title above to open the LCGC North America October 2017 regular issue, Vol 35 No 10, in an interactive PDF format.

Click the title above to open the October 2017 issue of Current Trends in Mass Spectrometry, Volume 15, Number 4, in an interactive PDF format.

Internal standards (IS) are commonly incorporated into quantitative methods to increase accuracy and precision. An IS is a compound that is different than the analyte of interest, has similar physicochemical properties to the analyte, and is added to samples, calibration standards, and quality control samples in a known quantity. It should not be present in the sample, it should be available in high purity, and it should be easily differentiable from the analyte of interest.

The Chinese American Chromatography Association (CACA) invites nominations for three awards: the 2018 CACA Young Investigator Award; the 2018 CACA Student Excellence Award; and the HPLC 2018 Student Travel Award.

Incognito wonders where we are, where we have been, and where we are going digitally in the analytical laboratory.

Peak Scientific has announced a new partnership with SEKO logistics intended to optimize its supply chains across the Chinese and U.S. markets.

Researchers from the Japanese Institute of Neuroscience have identified differences in the low-molecular-weight metabolite profiles of the brains of schizophrenia patients using CE–TOF-MS.

Researchers from the University of Torino have developed a novel HPLC–HRMS application for evaluating cosmetic ingredient composition. The application was used to analyze and compare sturgeon eggs, commonly known as caviar, and brill eggs, and their use in beauty creams as lipid sources.

Capillary electrophoresis (CE) is routinely used for chemical and biochemical analysis methods, and recently the technique has been implemented on microchips. R. Scott Martin, a professor and chair of chemistry at Saint Louis University, St. Louis, Missouri, USA, has been investigating ways to improve these techniques for years. He recently spoke to us about his research coupling microchip electrophoresis with electrochemical detection, coupling continuous flow with microchip electrophoresis with valving, coupling microchip CE with microdialysis sampling and electrochemistry, and more.

The ability to rapidly screen stationary phases through column-switching capabilities provides significantly greater efficiency in method development than was previously possible. The approach does require some additional hardware and software. And, while such capabilities may limit the ability to expand one’s literary knowledge during excessive months in the laboratory developing separation methods, real progress to key decision points for method optimization can be realized instead.

With the increasing proliferation of UHPLC, with its very much reduced extra column volumes, is the concept of dwell volume still relevant? Indeed, in your world, was it ever relevant at all?

Click the title above to open The Column September 12, 2017 North American issue, Volume 13, Number 13, in an interactive PDF format.

 Nominate a colleague or yourself for the 2019 LCGC Emerging Leader in Chromatography AwardSubmission Deadline: October 16, 2017

Nominate a colleage or yourself for the 2019 Lifetime Achievement in Chromatography AwardSubmission Deadline: October 16, 2017

How do non-alkylsilica columns provide us an additional dimension of column selectivity?

Small differences in process gas chromatography (GC) results from the same sample stream over time can indicate corresponding changes in target analyte concentrations, or the fluctuations might be due to external influences on the instrument. This instalment of ”GC Connections” explores ways to examine such results and better understand their significance.

Using a liquid chromatography–mass spectrometry (LC–MS) method in conjunction with two complementary types of chromatographic retention modes-reversed phase and aqueous normal phase-various compounds present in mesquite flour extracts were identified. Because of the diverse types of chemical constituents found in such natural product extracts, a single chromatographic mode may not be sufficient for a comprehensive characterization. However, the combination of reversed-phase and aqueous normal phase LC can encompass a wide range of analyte polarity. This characterization of the composition of mesquite flour could be used in future studies to elucidate the beneficial health effects of its consumption.

In the previous instalment, we presented a case of periodically fluctuating data that did not lend itself well to trend analysis with conventional statistical methods. The data did appear to have a strong regular fluctuation, but its relationship to other observations was not clear. This instalment addresses methods for teasing out external influences on trending data.

The 45th International Symposium on High Perfomance Liquid Phase Separations and Related Techniques (HPLC 2017), cochaired by Michal Holc€apek and František Foret, was held 18–22 June in Prague, Czech Republic. This instalment covers some of the highlights observed at the symposium, including advances in large-molecule separations, multidimensional chromatography, and areas of growing application of high performance liquid chromatography (HPLC). In addition, trends and perspectives on future developments in HPLC noted from the conference are presented.

Polybrominated diphenyl ethers (PBDEs) are a worldwide contamination problem. Structurally similar to polychlorinated biphenyl (PCBs), these compounds are long-lived in the environment and can bioaccumulate throughout the food chain. The health hazards of these chemicals have attracted increasing scrutiny and, as such, a great deal of research and regulations have been implemented to manage and control them.

Perfluorinated alkyl acids are man-made fluorochemicals used as surface-active agents in the manufacture of a variety of products, such as firefighting foams, coating additives, textiles, and cleaning products. They have been detected in the environment globally and are used in very large quantities around the world. These fluorochemicals are extremely persistent and resistant to typical environmental degradation processes. As a result, they are widely distributed across the higher trophic levels and are found in soil, air, groundwater, municipal refuse, and landfill leachates. The toxicity, mobility, and bioaccumulation potential of perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), in particular, pose potential adverse effects for the environment and human health.

“Click” chemistry is a class of efficient and selective reactions that is characterized by quantitative yields, tolerance to a broad range of functional groups, facile experimental setup, and minimal synthetic workup. This class of reactions combines particularly well with controlled radical polymerization methods, such as atom transfer radical polymerization (ATRP), and the two techniques have been prolifically employed for the synthesis of a wide variety of novel polymeric materials, including (multi) block copolymers, stars, brushes, and gels. This note describes the analysis of multisegmented block copolymers prepared by click-coupling of block copolymers synthesized by ATRP.

Identifying Post-Translational Modifications in Monoclonal Antibodies Analyzing post-translational modifications-such as glycosylation, oxidation, and deamidation-at different levels can reveal different types of information.

Liposomes are often used as nanocarriers to encapsulate in their cores hydrophobic or highly toxic drugs, and deliver these drugs safely to target tissue. During drug nanocarrier research and development as well as production quality control, it is of great importance to monitor liposome size distributions accurately while also verifying drug encapsulation. FFF-MALS-DLS, consisting of field-flow fractionation (FFF) combined with multi-angle light scattering (MALS) and dynamic light scattering (DLS), is a powerful tool for characterizing the size, concentration, and structure of large nanoparticle ensembles.

This application note describes a combined approach of analytical method development and method transfer by direct emulation of different target HPLC systems.

Modern therapeutic antibody formats, such as bispecific antibodies (bsAbs), are on the rise. Bispecific antibodies are artificial proteins that recognize two different epitopes and can simultaneously bind to two different types of antigen. They can be used to redirect T cells to tumour cells, block two different signalling pathways simultaneously, dually target different disease mediators, and deliver payloads to targeted sites.

The 15th International Symposium on Hyphenated Techniques in Chromatography and Separation Technology (HTC-15) will be held at Cardiff City Hall, Cardiff, United Kingdom, from 24–26 January 2018.