FLICKR, NOAAFor more than 50 years, researchers have used gas chromatography-mass spectrometry (GC-MS) to identify unknown compounds within biological samples. But according to new work from Gary Siuzdak of the Scripps Research Institute in La Jolla, California, and his colleagues, the method’s heating stage, used to volatilize and separate sample components, changes or destroys many of the compounds analyzed. Siuzdak’s team published its results this month (October 4) in Analytical Chemistry, questioning whether GC-MS is picking up the desired compounds of a sample or simply thermal degradation products.
“We found that even relatively low temperatures used in GC-MS can have a detrimental effect on small-molecule analysis,” Siuzdak told Chemical & Engineering News (C&EN). Molecular transformation from sample heating “has been a fundamental yet unrecognized problem with GC-MS technology since its inception,” he added. “I remember asking someone about it many years ago during the question period after his talk, and he simply didn’t know how to respond. For me, it has always been the elephant in the room.”
Siuzdak and his colleagues tested the effects of heating by analyzing known small molecules and human plasma metabolites with liquid chromatography-MS (LC-MS), which does not involve a heating stage, and comparing those results to identical samples that had been heated to 60 °C, 100 °C, ...
