液相色谱-氢化物发生原子荧光光谱法测定富硒酵母中硒的形态

摘要

建立了富硒酵母中硒酸 Se(Ⅵ)、亚硒酸 Se(Ⅵ)、硒代蛋氨酸(SeMet)和硒甲基硒代半胱氨酸(SeMe-Cys)4种硒形态的高效液相色谱-氢化物发生原子荧光光谱(HPLC-HG-AFS)分析方法。样品采用蛋白酶ⅩⅣ和胰蛋白酶酶解提取,20 mmol/L (NH4)2HPO4为流动相,经PRP-X100阴离子交换色谱柱分离后HG-AFS测定。结果显示,4种硒形态标准曲线的线性关系良好(R2≥0.9995),方法检出限为0.5~5.0μg/kg,平均回收率为82.5%~101.2%,日内相对标准偏差≤8.6%,日间相对标准偏差≤14.5%。本方法前处理简单、灵敏度高、设备便宜、运行费用低廉,适用于富硒饲料产品中硒的形态分析。%A rapid and sensitive method has been developed for the simultaneous determination of four selenium species Se(Ⅵ), Se(Ⅵ), selenomethionine, and Se-methylselenocysteine in Se-enriched yeast by liquid chromatography-hydride generation atomic fluorescence spectrometry (HPLC-HG-AFS). The isolation of the analytes from yeast samples was accomplished by proteaseⅩⅣ and trypsin enzymatic digestion. The target compounds were separated on a PRP-X100 anion exchange column and analyzed by HG-AFS. The mobile phase was 20 mmol/L (NH4)2HPO4. Good linearity was obtained for all the selenium species, with linear correlation coefficients higher than 0. 9996. The LODs of the four species were between 0. 5 and 5. 0 μg/kg. Average recoveries for the four analytes were in the ranges of 82 . 5%-101 . 2%, with intra-and inter-day RSD lower than 8. 6% and 14. 5, respectively. The proposed analytical method is simple, sensitive, with low operation cost, making it applicable for the determination of the selenium species in Se-enriched feeds.