SPME for on-line volatile organic selenium speciation

A method for speciation of volatile organo-selenium compounds is presented, using solid phase microextraction (SPME), thermal desorption by an in-house developed desorption unit and detection by different detectors such as AAS and ICP-MS. The procedure is simple, efficient, fast and solvent free. Dimethylselenium and dimethyldiselenium could be separated and quantified in less than two minutes, achieving detection limits of 0.7 and 0.9 mg L21, respectively, when ICP-MS detection was used. No additional chromatographic system for the species separation was needed. A broad range of fiber coatings were compared, finding that commonly used stationary phases such as PDMS show a highly reduced affinity for the investigated species. The method was applied to quantification of organo-selenium content in garlic samples.