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.