Pandurangappa Malingappa, Samrat Devaramani
Department of Studies in Chemistry, Bangalore University, Central College Campus, Dr Ambedkar Veedi, Bangalore-560 001, India.
Anal Sci. 2010 Jan;26(1):83-7. doi: 10.2116/analsci.26.83.
A sensitive surfactant-mediated extractive spectrophotometric method has been developed, based on the reaction of ferric iron with sulfide to form ferrous iron and its subsequent reaction with ferricyanide to form Prussian Blue, to quantify trace levels of hydrogen sulfide/sulfide in environmental samples. The method obeys Beer's law in the concentration range 2-10 microg of sulfide in 25 mL of aqueous phase with molar absorptivity (epsilon) of 3.92 x 10(4) L mol(-1) cm(-1). The colored species has been extracted into isoamyl acetate in the presence of a cationic surfactant i.e. cetylpyridinium chloride, to enhance the sensitivity of the method with epsilon value 5.2 x 10(4) L mol(-1) cm(-1). The relative standard deviation has been found to be 0.69% for 10 determinations at 4 microg of sulfide and the limit of detection was 0.009 microg mL(-1). The interference from common anions and cations has been studied. The proposed method has been applied to the determination of residual hydrogen sulfide in the laboratory fume hood as well as ambient atmospheric hydrogen sulfide in the vicinity of open sewer lines after fixing the analyte in ionic form using suitable trapping medium.
已开发出一种灵敏的表面活性剂介导萃取分光光度法，该方法基于三价铁与硫化物反应生成二价铁，随后二价铁与铁氰化物反应生成普鲁士蓝，用于定量环境样品中痕量的硫化氢/硫化物。该方法在25 mL水相中硫化物浓度为2 - 10 μg范围内符合比尔定律，摩尔吸光系数（ε）为3.92×10⁴ L·mol⁻¹·cm⁻¹。在阳离子表面活性剂即十六烷基吡啶氯化物存在下，有色物质已被萃取到异戊醇中，以提高该方法的灵敏度，ε值为5.2×10⁴ L·mol⁻¹·cm⁻¹。对于4 μg硫化物进行10次测定，相对标准偏差为0.69%，检测限为0.009 μg·mL⁻¹。研究了常见阴离子和阳离子的干扰。在使用合适的捕集介质将分析物固定为离子形式后，所提出的方法已应用于实验室通风橱中残留硫化氢的测定以及露天下水道附近环境大气中硫化氢的测定。
