反相HPLC测定钒、铌、钽的2_（2－吡啶偶氮）－5－二乙氨基苯酚配合物

Determination of Vanadium, Niobium and Tantalum as Their 2-(2-Pyridylazo)-5-diethylaminophenol Chelates by Reversed-phase HPLC

以２－（２－吡啶偶氮）－５－二乙氨基苯酚（ＰＡＤＡＰ）为柱前衍生试剂，在含０．１％酒石酸的１０ｍｍｏ１／Ｌ（ｐＨ３．５）ＨＡｃ－ＮａＡｃ缓冲溶液的甲醇／水（５０∶５０，Ｖ／Ｖ）中（５８０ｎｍ检测），在Ｃ１８柱上于１１ｍｉｎ内实现了Ｖ、Ｎｂ、Ｔａ的同时分离及测定，检出限（Ｓ／Ｎ＝３）为０．３４、０．２９、７．３０ｎｇ／ｍＬ。该法灵敏度高，用于矿样分析所得结果与推荐值相符，标准加入回收率为９９．０％～１０１．１％。

Elements V,Nb and Ta have extremely similar chemical properties.They interference seriously with each other in their analysis,and it is difficult to determine the single element.In this paper,2-(2-pyridylazo)-5-diethylaminophenol(PADAP)is used as the precolumn derivative reagent for the first time and the simultaneous determination of V,Nb and Ta has been achieved in 11 min at 580 nm on C18 column with mathanol-water(50/50, V/V)containing 0.1%tartaric acid and l0 mmol/L pH=5 acetate buffer as the mobile phase.The detection limits are 0.34,0.29 and 7.30 ng/mL for V,Nb and Ta respectively when the ratio of signal to noise is 3.This method is sensitive and has been applied to the analysis of mineral.The results correspond with the certified values and the recoveries of 99.0%─101.1%are obtained.