4-(5-溴-2-噻唑偶氮)间苯二酚反相阳离子对HPLC测定痕量铌、钒、铑、铬

本文报道新试剂4-(5-溴-2-噻唑偶氮)间苯二酚(5-Br-TAR)为柱前衍生试剂，以阳离子表面活性剂作为对离子试剂，用含15 mmol／L的pH 5.8的乙酸-乙酸钠缓冲溶液、0.05 mmol／L溴化钠、10 mmol／L TBA·Br的乙腈-甲醇-水(42 : 13：45，V／V／V)三元体系为流动相，在C8柱上25min内HPLC测定了Nb(V)、V(V)、Rh(Ⅲ)和Cr(Ⅵ)的5-BR-TAR螯合物。当SNR=2时，检出限分别为Nb(V)1.0、V(V)1.6、Rh(Ⅲ)0.9和Cr(Ⅵ)1.9μg／L。该方法用于测定污水中的铬和钒，结果良好。

Reversed-Phase HPLC Determination of Niobium, Vanadium, Rhodium and Chromium as Their (5-Bromo-2-Thiazolylazo) Resorcinol Chelates

The use of 4-(5-bromo-2-thiazolylazo) resorcinol (5-Br-TAR) as a derivatizing reagent in the reversed-phase high performance liquid chromatography (RP HPLC) separation and determination of Nb ( V ), V( V ), Rh ( Ⅲ ) and Cr ( Ⅵ ) was described in this paper. Acetonitrile-methanol-water (42: 13 : 45 V/V/V) containing 15 mmol/L pH 5.8 acetate buffer solution, 10 mmol/L tetrabutylammoniurn bromide and 0.5 mmol/L sodium bromide was used as the mobile phase. An octyl bonded silica was used as the stationary phase. The derivatization conditions of the four metal chelates were also described. 570 nm was selected as the detection wavelength. The four chelates were separated completely within 25 min. A few foreign ions could interfere with the detection. When the signal to noise ratio was 2, the detection limits were 1. 0, 1. 6, 0. 91 and 1. 9 μg/L for No(V), V(V), Rb(Ⅲ) and Cr(Ⅵ), respectively. This method has been applied to the determination of trace Cr( Ⅵ ) and V ( V ) in sewage with satisfactory results.