SPME for on-line volatile organo-selenium speciation

Abstract

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 µg L⁻¹, 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.