钯铁合金镀液和镀层中钯和铁的同时测定

Simultaneous Determination of Iron and Palladium in Electroplat ing Solution and Electroplated Layer of Palladium Iron Alloy

在酸性介质中，铁和钯分别与亚硝基Ｒ盐（ＮＲＳ）络合形成绿色的Ｆｅ－ＮＲＳ和红色的Ｐｄ－ＮＲＳ．利用它们的吸收光谱性质的差异，可用双波长系数法在水相中同时测定Ｆｅ和Ｐｄ．实验证明，两络合物的摩尔吸光系数分别为１．９４×１０４（对铁）和１．６３×１０４（对钯），线性范围分别为０～６０μｇ／ｍＬ和０～７０μｇ／ｍＬ，相对标准偏差小于０．５％，回收率为９６％～１０５％．本方法简便、快捷、准确、重现性好．适用于合金镀液及镀层中铁和钯的同时测定．

Fe (II) and Pd (II) ions can complex with NRS to form green Fe NRS and red Pd NRS respectively in the acid medium. Taking advantage of the difference of their absorption spectra property, the contents of Fe and Pd can be simultaneously determined by dual wavelength spectrophotometry in the aqueous phase. The molar absorptivities of the two complexes are found to be 1.94×10 4(for Fe)and 1.63×10 4(for Pd).The linear ranges are in 0～60 μg/mL(for Fe)and 0～70 μg/mL(for Pd).The relative standard deviations are less than 0.5 %, and the recoveries are 96%～105%. This method is rapid, simple, reproducible and accurate.And it is applicable to determine the contents of Fe and Pd in their alloy.