All News

Figure-2_web-1.jpg

Solid-phase microextraction (SPME) in conjunction with gas chromatography–mass spectrometry (GC–MS) is a simple and effective way to sample analytes. Ordinarily the coated fiber is rid of compounds during desorption in the GC, allowing for the analysis of a new sample. Carryover of the analyte between samples, however, is a problem with many chemicals. Our data shows that heating the fiber in a high temperature injection port for only 2 min between runs prevents carryover. The short heating between samples improves the linearity of the peak area versus concentration relationship over four orders of magnitude of concentration, with a limit of detection below 10-7 M in every case. Although carryover is an acknowledged problem with SPME fibers, such short conditioning steps are rarely considered as a means to eliminate it; this study suggests that they should be evaluated as an option.

Interest in chromatography using hydrophilic interaction liquid chromatography (HILIC) has continued to build in recent years. Adoption of the technique has been slowed by experiences of poor reproducibility. In particular, re-equilibration times in HILIC have been reported as being exceptionally long as compared to reversed-phase chromatography. In this study, re-equilibration times in HILIC, for both aqueous–organic gradients and buffer gradients are systematically explored. The results not only promise to improve method development practices, but also provide insight into HILIC retention mechanisms across mechanistically differing polar stationary phases.

Bartle, Adlard.jpg

Keith Bartle, Emeritus Professor of Physical Chemistry and Visiting Professor in the Energy Centre of the University of Leeds, UK, has been a creative catalyst in a wide range of chromatographic collaborations stretching from the analysis of methane in air to printing inks. He spoke to Caroline West from the University of Orléans, in Orléans, France, about his career in chromatography and his proudest scientific achievements in separation science, including his research in supercritical fluid chromatography (SFC), gas chromatography (GC), and “the unified chromatograph”.

figure 1.jpg

Interest in chromatography using hydrophilic interaction liquid chromatography (HILIC) has continued to build in recent years. Adoption of the technique has been slowed by experiences of poor reproducibility. In particular, reequilibration times in HILIC have been reported as being exceptionally long as compared to reversed-phase chromatography. In this study, reequilibration times in HILIC for both aqueous–organic gradients and buffer gradients are systematically explored. The results not only promise to improve method development practices, but also provide insight into HILIC retention mechanisms across mechanistically differing polar stationary phases.

table 11481117559843.jpg

Opiate abuse is drastically on the rise in the United States. In addition to traditional naturally occurring opiate compounds, forensic toxicologists also need to be able to rapidly identify synthetic opioid-like drugs. A rapid, three-step solid-phase extraction (SPE) procedure for the identification and quantification of fentanyl and its major urinary metabolite norfentanyl, in addition to four “designer” compounds, U-47700, W-18, W-15, and furanyl fentanyl, is presented here. As a result of the rapid use and abuse of fentanyl in medical and recreational settings, respectively, it is important to develop a method that can accurately extract this Schedule II drug from any other novel compounds that may be present.

Researchers investigating paper mill effluents and their impact on surface waters in Slovenia have identified endocrine disrupting compounds (EDCs) and their mutagenic and genotoxic properties using gas chromatography–mass spectrometry (GC–MS).

SEC.jpg

The ability of size-exclusion chromatography (SEC) to measure critical protein characteristics, such as molecular weight and size, makes the technique valuable from the early stages of novel protein research and development through to formulation and manufacturing support, especially in oligomeric purity and aggregation studies. However, informational output, ease of analysis, and sample requirements all vary considerably depending on whether a system has been truly optimized for protein characterization. This article examines how SEC works and considers how to maximize the productivity, sensitivity, and value of an SEC setup for biopharmaceutical development.