2-(4-羧基苯偶氮)苯并噻唑固相萃取分光光度法测定钯的研究

Study on solid phase extraction and spectrophotometric determination of palladium with 2-(p-carboxylphenylazo) benzothiazole

根据新试剂2-(4-羧基苯偶氮)苯并噻唑(CPABT)与钯的显色反应以及C8固相萃取小柱对显色络合物的固相萃取,建立了一种测定痕量钯的新方法。在pH值为5.9～7.5的磷酸二氢钾-磷酸氢二钾缓冲介质中,在十二烷基苯磺酸钠(SDBS)存在下,钯与CPABT发生反应形成1∶1的稳定络合物。该络合物可用C8固相萃取小柱富集,富集的络合物可用甲醇洗脱后分光光度法测定。在富集后的测定溶液中,络合物最大吸收波长为510nm,摩尔吸光系数ε=1.61×105L/(mol.cm),Pd2+质量浓度在0.1～1.0μg/ml范围内符合比尔定律。该方法用于测定催化剂中钯的含量,结果令人满意。

Based on the color reaction of 2-（p-carboxylphenylazo） benzothiazole （CPABT） with palladium（ Ⅱ ） and the solid phase extraction of its colored complex with C8 cartridge, a new method for the determination of trace palladium is studied. In the presence of SDBS and KHEPO4-K2HPO4 buffer solution （ pH 5.9 - 7.5 ） medium, CPABT reacts with palladium（ Ⅱ ） to form a stable 1： 1 complex. The colored complex is extracted by C8 cartridge and eluted the retained chelate from cartridge with methanol, then can be determined by spectrophotometry at 510 nm. Beer＇s law is obeyed in range of 0.1 -1.0μg/ml and ε = 1.61 × 10^5 L/（ mol · cm）. The method is applied to determine the trace palladium in the catalysts with a satisfactory result.