显色剂N-烯丙基-N'-(氨基对苯磺酸钠)硫脲与钯(Ⅱ)显色反应的研究和应用

Colour Reaction of N-A\lyl-N'-(sodium p-aminobenzenesulf o-nate)thiourea With Palladium( II ) and Its Application

本文报道了极易溶于水的显色剂N-烯丙基-N＇-(氨基对苯磺酸钠)硫脲(ASATu)光度法测定钯(Ⅱ)的条件:在pH4.0～5.5缓冲介质中,ASATu与钯生成易溶于水的、稳定的黄色络合物,组成比为:Pd(Ⅱ):ASATu=1:4;络合物的最大吸收波长为296.0nm,表观摩尔吸光系数ε_(296)=1.33×10～5L·mol～(-1)·cm～(-1);钯(Ⅱ)在0～20μg/25 mL呈线性,相关系数γ=0.9995.该法灵敏度高、选择性好、操作简便,用于阳极泥和矿石中钯的测定,结果满意.

N-Allyl-N'-(sodium p-aminobenzenesulfonate)thiourea (ASATu) was used as a colour reagent for the determination of Pd2+. In HAc-NaAc buffer solution at pH 4. 0-5. 5, ASATu reacts with Pd2+ to form a stable yellow water soluble complex with a molar ratio of Pd( Ⅱ ): ASATu of 1 : 4. The apparent molar absorptivity of the complex is 1. 33×105· L mol-1· cm-1 at 296. 0 nm. Beer's law is obeyed in the range of 0-20 ug Pd2+/25 mL, correlation coefficient is 0. 9995. The detection limit is 1. 92 × 10-7 mol/L. Relatively large amounts of usual ions are tolerated for the determination of Pd2+. This method has been applied to the determination of palladium in anode slime and mineral with satisfactory results. The relative standard deviation(n = 6) is 0. 87%-1. 63%, and the standard recovery is 95. 2%-97. 2%.