The determination of selenium in nutritional supplement formulas by flow injection-hydride generation coupled to graphite furnace atomic absorption spectrometry

Flow injection-hydride generation coupled to a transversely heated graphite atomizer (TOGA) is used for the determination of Se in microwave-digested nutritional supplement formulas. In this manner, Se is separated from the sample matrix prior to determination, eliminating matrix interferences encountered in direct determinations by GFAAS. Quantitative spike recoveries are obtained for formulas intended for consumption by infants and adults. A sub-ppb method detection limit is obtained for a 500-μL sample volume (O.6 ng/mL Se), sensitivity is increased over an order of magnitude compared to conventional THGA-GFAAS, and the relative standard deviation for a 5-ng/mL Se(IV) standard is 1.61% (n = 3)