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Hydrophilic Interaction Chromatography can be a very useful tool in our analytical armory, however there are some practical peculiarities to this chromatographic mode which need to be understood in order to ensure success. 

• Raptor C18 SPP 5 μm core-shell silica particle columns offer excellent resolution for fluorochemicals with short total cycle times. For even faster analysis, 2.7 μm core-shell particles are available. • Meets EPA Method 537 requirements. • Unique, robust Raptor C18 column design increases instrument uptime.

Utilizing Hamilton’s CO-RE® disposable tips with DPX technology provides a fast, accurate, and simple extraction method for analyzing drugs of abuse in urine. The Microlab NIMBUS equipped with a CO-RE 96-channel Multi-Probe Head (MPH) allows for high-throughput, automated sample processing.

The US EPA monitors a variety of chemicals in water that may cause harm to humans or wildlife to minimize exposure.

Get the most from your method by considering what you want it to do and setting appropriate chromatographic parameters.

Fabrice Gritti discusses how to separate and quantify both volatile and nonvolatile compounds in complex mixtures.

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.

Polycyclic aromatic hydrocarbons (PAHs) are found worldwide and are emitted from a number of sources including fossil fuel, coal and shale oil derivatives, coke production, and burning wood for home heating, and generally arise from incomplete combustion. Surface water supplies, such as water in ponds, may be used for recreational purposes or become a drinking water source. Characterization of PAHs and their concentration is of interest in maintaining public health.

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.

Mycotoxins are secondary metabolites produced by several species of fungi and are considered one of the most significant contaminants of agricultural commodities, both in the field and in storage. Agricultural products that may be affected include cereals, spices, dried fruits, and various nuts. Although hundreds of mycotoxins are known, relatively few are considered to pose a significant health risk. Aflatoxins, in particular aflatoxin B1, are genotoxic and carcinogenic and may cause liver cancer in humans, whilst ochratoxin A and the trichothecenes HT-2 and T-2 can cause various toxic effects. Monitoring and control of certain mycotoxins is important within the food industry because of their potential toxicity at low levels to both humans and animals.

Gas chromatography–mass spectrometry (GC–MS) allows isolation and identification of individual analytes within a complex mixture. Helium has traditionally been the first-choice carrier gas, owing to its inertness, performance, and relatively cheap price. Since 2001, however, helium has become increasingly expensive with a reported global increase in price of 500% between 2001 and 2016 (1). In 2012–2013, the global helium shortage increased the number of GC users switching to alternative carrier gases and improved the availability of information on their use.

Coffee is one of the most widely consumed beverages in the world, partly because of the stimulating effect of its caffeine content. Like most crops, the application of pesticides in coffee cultivation is a common practice to increase production yields. This application note details an optimized method for the extraction and cleanup of pesticide residues from coffee using a QuEChERS extraction procedure followed by a silica gel solid-phase extraction (SPE) cleanup.

While on-line multi-angle light scattering (MALS) is one of the most important techniques for macromolecular characterization, it can be made even more versatile with the addition of a quasielastic light scattering (QELS, a.k.a. dynamic light scattering) module for determination of hydrodynamic radius. QELS can be added to a Wyatt MALS system as a WyattQELS™ module embedded in the MALS instrument, or by connecting the MALS flow cell to a batch DLS instrument such as a DynaPro® NanoStar® or Mobius® via optical fibre. The QELS instruments can be used to determine the hydrodynamic radius, rh , for a variety of samples in a continuous‑flow mode. The combined MALS-QELS system will measure simultaneously rg, rh, and the absolute molar mass.

Click the title above to open the LCGC Europe July 2017 regular issue, Vol 30, No 8, in an interactive PDF format.

Click the title above to open the LCGC North America July 2017 regular issue, Vol 35 No 7, in an interactive PDF format.

Click the title above to open the July 2017 issue of Current Trends in Mass Spectrometry, Volume 15, Number 3, in an interactive PDF format.

I believe that the term “top-down proteomics” holds a particular connotation with respect to the use of ultrahigh-resolution mass spectrometers in people’s minds. And rightfully so. If one is to determine with confidence the sequence and charge state of a particular fragment ion generated in the gas phase, then high mass accuracy is a must. From the discovery side of things, where qualitative analysis is most important, this is not likely to change. However, when you turn to quantitative analysis, where you want to now monitor levels of a particular protein biomarker for the purpose of disease diagnosis, prognosis, or treatment, then invariably bottom-up strategies are the norm. Protein quantitation using top-down strategies, especially on low-resolution triple-quadrupole systems, have been largely ignored, until recently .

Thermo Fisher Scientific has been selected as a partner of INTELLItrace Work Package (WP) 18, part of the European Food Integrity Project aimed at developing a validation of untargeted methods to assure the quality, authenticity, and safety of the food chain.

Researchers have developed and validated a stability- and potency-indicating assay protocol for high-throughput quality assessment of vaccines consisting of recombinant virus- “like” particles (VLPs) using conformation-dependent antibodies coupled to size-exclusion high performance liquid chromatography (SE-HPLC).

Fluence Analytics, formerly Advanced Polymer Monitoring Technologues (APMT), has announced an increase in investment led by Energy Innovation Capital (EIC) but also including participation from other investors.

Researchers from the Chinese Academy of Science in Beijing, China, have used high‑performance size-exclusion chromatography (HPSEC) and differential scanning calorimetry (DSC) to study the stabilization of inactivated foot and mouth disease virus.