H-point standard addition method in the analysis by differential pulse anodic stripping voltammetry Simultaneous determination of lead and tin.
ABSTRACT The applicability of H-point standard addition method (HPSAM) to the resolving of overlapping differential pulse anodic stripping voltammetric peaks corresponding to the oxidation of lead and tin is verified. The results show that the H-point standard addition method is suitable for the simultaneous determination of lead and tin in aqueous media. The results of applying the H-point standard addition method showed that Sn(2+) and Pb(2+) could be determined simultaneously with the concentration ratios of Sn(2+) to Pb(2+) varying from 1:5 to 10:1 in the mixed sample. The proposed method has been successfully applied to the simultaneous determination of lead in the presence of tin in some synthetic samples. Moreover, the applicability of the method was demonstrated by the recovery of lead in a canned soft drink sample.
Article: Speciation analysis of Sn(II) and Sn(IV) using baker’s yeast and inductively coupled plasma optical emission spectrometry[show abstract] [hide abstract]
ABSTRACT: The use of Saccharomyces cerevisiae as a substrate to selectively retain Sn(II) and Sn(IV) has been investigated. Several factors affecting the retention of the analytes by yeast, such as pH, amount of biomass, temperature and time of contact were evaluated. Based on this study, a method for determination of Sn(II) and Sn(IV) combining inductively coupled plasma optical emission spectrometry (ICP OES) and solid phase extraction using Saccharomyces cerevisiae is proposed. The procedure consists of the selective retention of Sn(IV) by yeast at pH = 2.0 while Sn(II) remains in solution. Determination of tin in the solid phase was easily carried out by submitting a slurry of the yeast (0.5 g/40 mL) directly to ICP OES. The precision of the extraction procedure was characterized by an RSD lower than 4%. The detection limits of tin (3σ) in the solid phase and the liquid phase were 1.1 and 0.7 µg L−1, respectively. The proposed approach was evaluated for determination of Sn(II) and Sn(IV) in spiked river water and real samples of industrial waste water (untreated and treated). For all samples, recoveries of spiked Sn(II) and Sn(IV) were between 85 and 112%.Microchimica Acta 02/2007; 157(3):201-207. · 3.03 Impact Factor