对二乙氨基苯基亚甲基若丹宁固相萃取光度法测定氰化渣中铂的研究

Study on solid phase extraction and spectrophotometric determination of trace platinum in cyanide residue with p-diethylaminobenzylidenerhodanine

根据对二乙氨基苯基亚甲基若丹宁 (DEABR)与铂的显色反应及C18固相萃取小柱对显色络合物的固相萃取 ,并结合微波溶解样品 ,建立了一种测定氰化渣中铂的方法。氰化渣样品用微波密闭溶解 ,试液中的铂在pH为 2 .0的氯乙酸 -氢氧化钠缓冲介质中、乳化剂 -OP存在下与DEABR生成 2∶1稳定络合物 ;该络合物可被C18固相小柱萃取富集 ,用氮 -氮二甲基甲酰胺 (DMF)洗脱 ,富集倍数可达 5 0倍 ,洗脱液定容后用光度法测定 ;该络合物λmax=5 45nm ,ε =8.85×10 4 L/ (mol·cm) ,铂质量浓度在 0 .0 1～ 2 .0mg/L内符合比尔定律。该方法用于氰化渣中铂的测定 ,结果令人满意。

Based on color reaction of p diethylaminobenzylidenerhodanine (DEABR) with platinum and the solid phase extraction of its colored complex with C 18 cartridge,a new method of determining platinum in cyanide residue was developed.With the presence of pH 2.0 buffer solution and emulsifier OP medium,DEABR reacted with platinum(Ⅱ) to form a stable 2∶1 complex.The colored complex can be enriched by C 18 cartridge and eluted the reained chelates from cartridge with DMF,and then the eluant was determined by spectrophotometer at 545nm.Beer's law was obeyed in range of 0.01～ 2.0mg/L .This method has been applied to determine platinum in cyanide residue with satisfactory results.