Vacuum Ultraviolet Absorbance Spectra – When a Little Means a Lot

Posted by Jack Cochran on March 27, 2017

Hopefully you read my last blog post on using vacuum ultraviolet (VUV) spectroscopy as a powerful detection means for gas chromatography (GC) of terpenes.  If so, you may remember that where VUV shines (a little spectroscopy joke for you) is producing unique absorbance spectra for the various terpenes, even isomers.  Unique spectra are what allow deconvolution of coeluting GC peaks, something I know a bit about from working with time-of-flight mass spectrometers. In mass spectrometry (MS), a (mostly) unique m/z ion for each coelutingcompound is what allows a mathematical routine to get going for deconvolution, followed by plotting apexing m/z ions for each coeluting peak to get its true spectrum.  That logic has always been easy for me to wrap my mind around.  It’s also simple to see how that same MS deconvolution approach fails for coeluting isomers since isomers have essentially identical mass spectra. 

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Building the VUV Entourage in Terpene Analysis

Posted by Jack Cochran on March 01, 2017

By Jack Cochran, Senior Director of Applications, VUV Analytics, Cedar Park, Texas, USA.

In a recent “In My View” article I wrote for The Cannabis Scientist, which is a “mini magazine” from The Analytical Scientist, I posed the question on whether it was more appropriate to analyze pesticides in cannabis samples using GC-MS/MS or LC-MS/MS.  Given the expense of capital equipment and the skills needed to operate it, this is not a trivial question.  However, the answer is made simple by considering one important thing, especially for medical marijuana: consumer safety.  To cover the full range of pesticides that are either currently used or have already been detected on cannabis, you need both techniques.  This doesn’t come as any surprise to analytical chemists analyzing residues on food, where GC-MS/MS and LC-MS/MS are routinely employed as complementary techniques to screen for hundreds of pesticides.

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Forensic Drug Analysis Simplified

Posted by Paul Johnson on February 10, 2017

Are you attending the American Academy of Forensic Sciences 69th Annual Meeting? If so, visit us at Booth 906! 

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When Chemistry Stops and Physics Begins

Posted by Norman Fraley on December 07, 2016

Norman Fraley, Principal Chemist Eurofins - Lancaster Laboratories

I hate derivatization. That being said, I love derivatization. What is there not to love about such an elegant chemical reaction where the purpose is to create something new from reagents you have just so you can see it and measure it better? Is your target compound thermally unstable? Derivatize it. Not volatile enough? Derivatize it. Your detector cannot see it well? Derivatize it. Is it too volatile? Yes, you guessed right – derivatize it. In my 30 years of analytical chemistry I have not found a more handy technique, although that does not mean it is simple or easy.

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Solving a Growing Problem in a Budding Industry

Posted by Paul Johnson on December 05, 2016

The abuse of synthetic cannabinoids by teenagers, young adults, and the homeless population has led to thousands of hospitalizations and overdose deaths over the past several years. These compounds are sold by international manufacturers and imported legally into the U.S. due to the synthesis of banned substance variants outpacing the DEA’s ability to identify them. We recently learned that the synthetic cannabinoid problem extends into to the business of legal cannabis production. A number of growers in the Pacific Northwest have been caught spraying their harvests with these synthetic compounds to increase the perceived potency of their products. Consumer safety is at risk while states like Washington, Oregon, and others work towards consensus on testing requirements and standardization of methods.     

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