Electrochemical hydride generation of tin(II) and its determination by electrothermal atomic absorption spectrometry with in situ trapping in the graphite tube atomizer

摘要

An electrolytic hydride generation system for the determination of tin(II) by means of batch electrochemical hydride generation-electrothermal atomic absorption spectrometry (EcHG-ETAAS) with in situ trapping in a graphite tube atomizer is described. The effects of four permanent chemical modifiers -palladium, tungsten, iridium, and platinum - for graphite tube treatment on analyte absorbance and the effects of four cathode materials, i.e., Pb, Sn, Pb-Sn alloy, and glassy carbon, are checked. Three electrolytes, i.e., nitric acid, sulfuric acid, and hydrochloric acid, are examined as catholyte solutions. The influence of several parameters on EcHG is investigated using multivariate and univariate methods. Interferences of some concomitant ions are evaluated. The calibration curve is linear from 1 to 200μgL~(-1), with a detection limit of 0.8μgL~(-1) and a relative standard deviation of 6.2% (n = 3) for 100μgL~(-1) Sn(II). The proposed method was successfully applied in the analysis of real environmental water samples and reference materials, and good spiked recoveries over the range of 93.1-115% were obtained. The proposed technique provides a means for developing hydride generation of other elements.