2,3,7-三羟基-9-水杨基荧光酮分光光度法测定痕量铌

Spectrophotometric Determination of Trace Amount of Niobium with 2,3,7-Trihydroxy-9-Sulicylfluoronc as Chromgenic Reagent

以酒石酸作为辅助络合剂,在表面活性剂溴化十六烷基吡啶存在下及pH 5.5的乙酸-乙酸钠缓冲溶液中,显色剂2,3,7-三羟基-9-水杨基荧光酮与铌(Ⅴ)形成稳定络合物,其最大吸收波长位于560nm处,据此提出了分光光度法测定铌钽矿浸出液中铌含量的方法。铌(Ⅴ)的质量浓度在4～240μg·L-1范围内符合比耳定律,表观摩尔吸光率为1.44×106L·mol-1.cm-1。方法用于铌钽矿样品中痕量铌的测定,测定结果与国家标准方法测定值相一致。

In a CH3COOH-CH3COONa buffer solution of pH 5.5,and in the presence of cetylpyridinium bromide,with tartaric acid as assisting complexant,a stable coordination complex between 2,3,7-trihydroxy-9-sulicylfluoronc and niobium（Ⅴ） was formed,with its absorption maximum at the wavelength of 560 nm.Based on these facts,a method of spectrophotometry for the determination of niobium in the extract of Ni-Ta ore was proposed.Beer′s law was kept in the range of 4-240 μg·L-1,with value of apparent molar absorptivity of 1.44×106L·mol-1·cm-1.The proposed method was applied to the determination of niobium in the extract of Ni-Ta ore,giving results in consistency with the results obtained by GB method