Determination of dimethylselenide and dimethyldiselenide by gas chromatography–photoionization detection

A simple method for the determination of volatile selenium compounds employing a gas chromatograph equipped with a photoionization detector is described. The method involves the direct injection of dimethylselenide (DMS) or dimethyldiselenide (DMDS) into the gas chromatograph; no derivatization of the sample was required. The photoionization detector was capable of detecting 60 pg (0.55 pmol) of DMS and 150 pg (0.80 pmol) DMDS. Sensitivity was 10–50 times greater with DMS and 4–20 times greater with DMDS when the photoionization detector was employed than when the flame ionization detector was employed.