阴离子树脂固相萃取光度法测定煤矸石中痕量钪

Spectrophotometric determination of trace scandium in coal gangue via solid phase enrichment of scandium with anionic resin

研究了铬天青S（CAS）与钪（Ⅲ）的显色反应,在pH6.0的HAc-NaAc缓冲溶液中,在氯化十四烷基砒啶（TPC）和乳化剂OP存在下,铬天青S（CAS）与钪（Ⅲ）反应生成物质的量比为2∶1的稳定配合物,该配合物可用DT-1016型阴离子树脂交换柱萃取富集,再通过树脂相光度法测定钪,由此建立了测定钪的光度法的新方法。吸附配合物树脂相的最大吸收波长为610 nm,表观摩尔吸光系数为1.43×10^5L·mol^-1·cm^-1。钪的质量浓度在0～360μg/L范围内符合比耳定律。经阴离子树脂交换柱萃取富集后,钪的测定灵敏度可提高数倍,大多数常见离子不干扰测定。方法应用于煤矸石痕量钪的测定,结果满意。实际样品分析结果的相对标准偏差〈5%,加标回收率为98.0%～103.0%。

The chromogenic reaction of chrome azurol S（CAS） with scandium（Ⅲ） was studied.It was found that chrome azurol S（CAS） could form with scandium（Ⅲ） a stable complex at a mole ratio of 2∶1 in a HAc-NaAc buffer solution with a pH value of 6.0 in the presence of tetradecyl pyridinium chloride（TPC） and an emulsifier OP,and the concentration of this complex could be enriched on the DT-1016 type anionic resin column.The resulted resin could be used to determine scandium by spectrophotometry at a maximum absorption wavelength of 610 nm.A new spectrophotometric method for determining trace scandium was developed.Its apparent molar absorptivity was 1.43×10^5 L·mol^-1·cm^-1.The Beer′s law was obeyed in a scandium（Ⅲ） concentration range of 0～360 μg/L.After this complex was concentrated by the DT-1016 type anionic resin column,the sensitivity for the determination of scandium could be improved by several times,and a lot of co-existing ions would not interfere with the analytical results.The method has been applied to the determination of trace scandium in coal gangue with satisfactory results.The relative standard deviation was less than 5% and the recoveries of samples were between 98.0% and 103.0%.