新试剂NSPAR固相萃取光度法测定氰化渣中铂的研究

Study on determination of trace platinum in cyanide residue by microwave-assisted digestion and solid phase extraction spectrophotometry

在pH2.5的氯乙酸NaOH缓冲介质中,吐温80存在下,磺硝酚偶氮若丹宁(NSPAR)与铂反应生成2∶1稳定络合物,该络合物可被WatersSep PakC18小柱固相萃取,用氮氮二甲基甲酰氨(DMF)洗脱后用光度法测定。在洗脱液介质中,λmax=535nm,摩尔吸光系数ε=6.33×104L·mol-1·cm-1。铂质量浓度在0 001～0 080μg/mL内符合比尔定律,本方法可用于氰化渣中铂的测定。

<Abstrcat>Based on a color reaction of 4-nitro-6-sulfophenolazorhodanine (NSPAR) with platinum and the solid phase extraction of its colored complex with C_(18) cartridge, a new method for the determination of platinum in cyanide residue was established. In a medium of pH 2.5 buffer solution and Tween-80 medium, NSPAR reacts with platinum (Ⅱ) to form a stable 2∶1 complex. The colored complex can be enriched by C_(18) cartridge and eluted from cartridge with DMF. Then the eluant was determined by spectrophotometry at 535 nm. Beer′s law is obeyed in range of 0.05～4.0 mg/50 L. This method was applied to the determination of platinum in cyanide residue with good results.