Miura Yasuyuki, Fujisaki Mutsuo, Haddad Paul R
Department of Chemistry, Faculty of Science, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan.
Anal Sci. 2004 Feb;20(2):363-7. doi: 10.2116/analsci.20.363.
A photometric method has been developed for the determination of sulfide at 10(-5) mol dm(-3) levels, which is based on the reaction of sulfide with a given excess amount of bismuth(III) to form a precipitate of bismuth(III) sulfide and on the spectrophotometric measurement of the residual bismuth(III) at 335 nm after extracting with bismuthiol II reagent from an aqueous solution containing acetate buffer into benzene. The presence of sulfite and thiosulfate up to 0.002 mol dm(-3) did not cause any interference in the determination of sulfide, because both sulfite and thiosulfate do not produce any precipitate with bismuth(III). A linear calibration plot with a negative slope was obtained for sulfide over the range of 5.00 x 10(-7) - 3.00 x 10(-5) mol dm(-3) (16.0 - 960 ppb). An experimental calibration plot was in accord with the theoretical plot, taking into account the known excess of bismuth(III), showing that the reaction of sulfide with bismuth(III) proceeded to completion. The relative standard deviation of results from 10 replicate determinations of standard sulfide (2.00 x 10(-5) mol dm(-3)) was 0.44%. The proposed method was successfully applied to the determination of sulfide in hotspring water samples without any pretreatment.
已开发出一种光度法，用于测定浓度为10⁻⁵ mol dm⁻³的硫化物。该方法基于硫化物与给定过量铋(III)反应生成硫化铋沉淀，并通过铋试剂II从含乙酸盐缓冲液的水溶液中萃取后，在335 nm处对残留铋(III)进行分光光度测量。高达0.002 mol dm⁻³的亚硫酸盐和硫代硫酸盐的存在对硫化物的测定没有造成任何干扰，因为亚硫酸盐和硫代硫酸盐都不会与铋(III)产生任何沉淀。在5.00×10⁻⁷ - 3.00×10⁻⁵ mol dm⁻³（16.0 - 960 ppb）范围内，硫化物得到了具有负斜率的线性校准曲线。考虑到已知过量的铋(III)，实验校准曲线与理论曲线相符，表明硫化物与铋(III)的反应进行完全。对标准硫化物（2.00×10⁻⁵ mol dm⁻³）进行10次重复测定的结果，相对标准偏差为0.44%。所提出的方法无需任何预处理，成功应用于温泉水样中硫化物的测定。
