HPLC-ICP-MS或HPLC-FAAS法分离测定硒化合物（英文）

DETERMINATION OF SELENIUM COMPOUNDS BY HPLC WITH ICP-MS OR FAAS AS SELENIUM-SPECIFIC DETECTOR

提出了一种用高效液相色谱（HPLC）分离和用电感偶合等离子体质谱仪（ICP－MS）或火焰原子吸收光谱仪（FAAS）作元素专一检测器在线测定硒的化学形态的方法。在优化的HPLC条件下，用ESAⅢ阴离子色谱柱（250mm×4．6mm），以柠檬酸铵为流动相（5．5mmol／L，pH5．5，流速1．5mL／min），进样量100μL，分离和测定三甲基硒离子、硒代蛋氨酸、亚硒酸和硒酸盐只需8min。HPLC－FAAS在线分析4种硒化合物的检测限为p（Se）=1mg／L。用超声雾化器作ICP－MS的接口，HPLC－ICP－MS在线分析4种硒化合物的检测限分别为P（Se）=0．34μg／L（亚硒酸），0．18μg／L（硒代蛋氨酸），0．08μg／L（三甲基硒离子）和0．07μg／L（硒酸盐）。与气动雾化器接口相比，信号强度增加7至31倍。

A speciation method was developed for selenious acid, selenic acid, trimethylselenonium ion (TMSe)and selenomethionine (SeMet). Separation of the four selenium species was achieved by HPLC on an ESA Anion Ⅲanion-exchange column using aqueous mobile phase of 5. 5 mmol/L ammonium citrate at pH 5. 5 with a flow rate of 1. 5 mL/min. Under the optimal conditions, the four selenium species were separated within 8 minutes. On-line selenium--specific detection was carried out with an inductively coupled plasma mass spectrometer (ICP-MS) or a flame atomic absorption spectrometer (FAAS). The detection limits of HPLC-FAAS were approximately p(Se)=1 mg/L for each compound (100 μL injection). To increase the nebulization efficiency of the ICP-MS, the Meinhard concentric nebulizer was replaced by an ultrasonic nebulizer (USN). The ICP-MS signal intensity was increased by a factor of 7 for selenious acid and 24 to 31 for TMSe, SeMet and selenic acid with the USN compared to that with the Meinhard nebulizer. The detection limits of the HPLC-USN-ICP-MS were p(Se)=0. 08 μg/L for TMSe, p(Se)=0. 34 μg/L for selenious acid, p(Se) = 0. 18 μg/L for SeMet and p(Se) =0. 07 μg/L for selenic acid.