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 150pg (0.80pmol) 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.