Speciation of inorganic selenium using flow injection hydride generation atomic fluorescence spectrometry

Abstract

Two methods based on flow injection atomic fluorescence have been developed in order to speciate Se as Se'"-SeV'. Both methods use hydride generation of Sew with atomic fluorescence detection as the derivatization-detection step. In the first method, two sample plugs are injected simultaneously in series, so that the first plug passes straight to the detector to determine Se'". The second plug passes through a focused microwave device where Se"' is reduced to Sew prior to its conversion into the hydride. The Se"' content is then given as the difference between the two results. In the second method a mini-column is used to retain both the Se species; Sew and Sen are then eluted sequentially with formic and hydrochloric acids, respectively. The columns can be used for preconcentration of the analytes as well as for sampling. Both methods show exceptional sensitivity [limits of detection (3s) of 0.04 pg 1-'1 and wide linear range up to 50 pg I-', with excellent linearity (9 = 0.999), and reproducibility (relative standard deviation<5%). The methods have been used in an intercomparison exercise for the Measurements and Testing Programme and have been applied to the determination of the analytes in tap water and haemodialysis samples.

Inorganic and organic selenium compound speciation with coupled HPLC-MW-HG-AFS

“…This approach employs a redox reagent also (a HBr/KBrO 3 mixture) in order to reduce all the species to selenium(IV) before the hydride generation step, and it is suitable for complex molecules, especially selenoamino acids. Other authors 16,17 have also employed atomic fluorescence detection (HPLC-MW-HG-AFS) for the speciation of inorganic selenium.…”

The macro‐ and micro‐element content of swedes and kale in Southland, New Zealand, and the effect of trace element‐amended fertilisers on their Co, Se, and Cu concentrations

“…To determine all elements except Se, Co, Mo, and I, the digesta were taken up in hot water and element concentrations determined by atomic absorption spectrometry. Selenium was determined by hydride generation (Bryce et al 1995), Co and Mo were complexed with 2-nitrosonaphth-l-ol and toluene-3,4-dithol, respectively, extracted in methyl isobutyl ketone, and then determined by atomic absorption spectrometry (Heanes 1981;Subramanian 1996), and I was determined after an alkaline ashing by an oxidation-reduction reaction (Sandell & Kolthoff 1937).…”

Fortification of silage and hay crops with trace elements

“…This sample was weighed, dried at 60°C and analysed chemically for Cu, I, Se, and Co. For Cu, Se, and Co, samples were digested in nitric/perchloric acids before being determined by the methods of Martinie & Schilt (1976), Bryce et al (1995), and Heanes (1981) respectively. Iodine was determined by colorimetry after dry ashing by the method of Moxon & Dixon (1980).…”