微波消解和固相萃取光度法测定氰化渣中痕量钯

Study on Solid Phase Extraction and Spectrophotometric Determination of Palladium in Cyanide Residue

根据 2_(2_喹啉偶氮 )_5_二甲氨基苯甲酸 (QADMAB)与钯的显色反应及C18固相萃取小柱对显色络合物的固相萃取 ,并结合微波消解样品 ,建立了一种测定氰化渣中痕量钯的方法。即在pH为 3 5的HAc_NaAc缓冲介质中 ,溴化十六烷基三甲胺 (CTMAB)存在下 ,QADMAB与钯反应生成 2 1稳定络合物 ,该络合物可被C18小柱萃取富集 ,富集的络合物用乙醇洗脱后用光度法测定 ,在乙醇介质中体系λmax=63 0nm ,ε=1 2 0× 1 0 5L·mol-1·cm-1。钯含量在 0 0 1～ 1 5mg L内符合比尔定律 ,方法用于氰化渣中钯含量的测定 ,结果令人满意。

Based on the color reaction of 2-(2-quinolinylazo)-5-dimethylaminobenzoic acid (QADMAB) with palladium(Ⅱ) and the solid phase extraction of its colored complex with C-{18} cartridge, a new method for the determination of palladium in cyanide residue was studied. In the presence of pH 3.5 HAc-NaAc buffer solution and CTMAB meidium, QADMAB reacts with palladium (Ⅱ) to form a stable 2/1 complex. The colored complex can be enriched by C-{18} cartridge and eluted the retained chelates by ethanol, then it can be determined by spectrophotometry at 630nm. Beer’s law is obeyed in the range of 0.01～1.5mg/L. This method was applied to the determination of palladium in cyanide residue with good results.