Simultaneous characterization of selenium and arsenic analytes via ion-pairing reversed phase chromatography with inductively coupled plasma and electrospray ionization ion trap mass spectrometry for detection applications to river water, plant extract and urine matrices.

With an increased awareness and concern for varying toxicities of the different chemical forms of environmental contaminants such as selenium and arsenic, effective methodologies for speciation are paramount. In general, chromatographic methodologies have been developed using a particular detection system and a unique matrix for single element speciation. In this study, a routine method to speciate selenium and arsenic in a variety of "real world" matrices with elemental and molecular mass spectrometric detection has been successfully accomplished. Specifically, four selenium species, selenite, selenate, selenomethionine and selenocystine, and four arsenic species, arsenite, arsenate, monomethlyarsonate and dimethylarsinate, were simultaneously separated using ion-pairing reversed phase chromatography coupled with inductively coupled plasma and electrospray ionization ion trap mass spectrometry. Using tetrabutylammonium hydroxide as the ion-pairing reagent on a C(18) column, the separation and re-equilibration time was attained within 18min. To illustrate the wide range of possible applications, the method was then successfully applied for the detection of selenium and arsenic species found naturally and spiked in river water, plant extract and urine matrices.