The Column-04-11-2016

Experienced gel permeation chromatography/size-exclusion chromatography (GPC/SEC) users know that equilibration of the columns takes much longer than the time needed by the pump to produce a constant flow. An analysis in this phase would clearly yield different results from those achieved after complete equilibration of GPC/SEC columns. Furthermore, false but constant flow rates affect the molar masses derived from a GPC/SEC calibration curve. An internal flow marker can help to increase reproducibility and accuracy of GPC/SEC results.

A glimpse of what can be expected at Analytica 2016.

A team of researchers has developed a high‑throughput analysis method for 192 diverse pesticides and 51 environmental contaminants in cattle, swine, and poultry meats. The team used a combination of low-pressure gas chromatography coupled to tandem mass spectrometry (LP)GC–MS–MS and ultrahigh-pressure liquid chromatography coupled to tandem MS in the analysis.

Researchers from the Joint Research Centre of the European Commission have published a case study detailing the characterization of new psychoactive substances using gas chromatography–mass spectrometry, nuclear magnetic resonance, high‑resolution tandem mass-spectrometry, and Raman spectroscopy.

Click the title above to open The Column April 11, 2016 North American issue, Volume 12, Number 6, in an interactive PDF format.

Click the title above to open The Column April 11, 2016 Europe & Asia issue, Volume 12, Number 6, in an interactive PDF format.

Gas chromatography (GC) is an established and well-understood technique. As the cannabis industry grows, demand for analytical robustness is increasing for analytes such as pesticides, residual solvents, and terpenes. GC and GC coupled to mass spectrometry (GC–MS) are effective tools to address the demands of laboratories, growers, manufacturers, and consumers. This article provides an overview of the types of compounds that can be analyzed by GC, reviews the strengths and weaknesses of the analytical methods, and discusses areas of opportunity for chromatography.

This article describes the use of a headspace thermal desorption–gas chromatography–time-of-flight mass spectrometry (headspace TD–GC–TOF-MS) method to analyze complex aroma profiles from hops, and highlights how it can provide a rapid yet robust approach when comparing similar samples. The article also examines the potential of “soft” electron ionization at 12 eV for distinguishing between structurally similar monoterpenoids and sesquiterpenoids to provide better characterization of the often subtle differences in headspace profiles between different hop varieties.

With the ever-growing market for new drugs to enhance performance of horses, analysts are continually battling to develop new analytical methods to beat doping. LCGC spoke to Karen Y. Kwok from The Hong Kong Jockey Club in Hong Kong, China, about her work in this area.