Analytical Methods for Elemental Se and Organo-Selenium

Non-volatile elemental and inorganic selenium, biologically formed in bacterial or plant samples, can be determined via atomic absorption spectrometry (AAS) 

Transmission electron microscopy energy dispersive X-ray analysis has also been used to image intracellular Se granules present from Se bioreduction in bacteria. Reduction of selenite and the deposition of elemental Se in cell cytoplasm or in the extracellular space may be lead to promising bioremediation schemes.172 

Methylated organo-selenium has been determined by GC/MS or fluorine-induced chemiluminescence to determine DMSe, DMDSe, and DMSeS. This last compound, dimethyl selenenyl sulfide, was mistakenly identified as dimethyl selenone (CH3Se02CH3) in earlier work with bacteria.181,182 However, much recent work with many microorganisms have shown ample evidence of DMSeS production from Gram-negative bacteria,181,183 phototrophic bacteria,167,184 phytoplankton185 and in B. juncea detailed above. SPME with microwave-induce plasma atomic emission spectrometry was recently used to 

Liquid chromatography/MS has also very recently been used for selenate and selenite determination and selenomethionine. And another recent liquid chromatographic hyphenated method, liquid chromatography-hydride generation atomic fluorescence spectrometry, has been used to determine selenite, selenate, selenocysteine, and selenomethionine in a single run. Reverse-phase and ion-exchange columns were used in series to accomplish the complex separation of all four of these analytes. And microchip capillary electrophoresis has most recently been used for determination of various Se-amino acids with negligible sample consumption . An excellent US Center for Disease Control summary of Se analytical methods is available.  

Methylated organo-selenium has been determined by GC/MS or fluorine-induced chemiluminescence to determine DMSe, DMDSe, and DMSeS. This last compound, dimethyl selenenyl sulflde, was mistakenly identified as dime- 

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