微波消解—原子荧光分光光度法测定稻米中硒含量

Determination of selenium content in rice by HG-AFS

以稻米为原料，通过对样品前处理条件、仪器测定条件优化，建立一种适于测定富硒稻米硒含量检测方法。结果表明，氢氟酸可加速复杂样品消解；最佳测定条件：5％盐酸为载流、20g／L硼氢化钠溶液作还原剂、光电倍增管负高压260V、灯电流50mA、原子化器高度8nm。经测，普通大米含硒量为80-90μg／kg，富硒大米含硒量为150～160μg／kg，两种大米均以米糠中含硒量最高；检出限为0．8×10^-4μg／L，加标回收率为94．2％～93．5％。该法简便，快速、准确。

This paper which rice was as raw material studies application of microwave digestion with atomic fluorescence spectrophotometer to determination of selenium content. The results showed that hydrofluoric acid may accelerate the digestion of the complex samples. Set the appropriate digestion procedures to shorten the digestion time. The optimal conditions as followed： 5% HCI as the carrier, 20 g/L NaBH4 as reducing agent, 260 V as photomultiplier tube negative high voltage, 50 mA as lamp current and , 8 mm as atomizer height .The selenium content of the ordinary rice was 80-90μg/kg and selenium-enriched rice was 150×160 μg/kg. The highest content of ordinary rice and seleniumenriched rice were rice bran. The detection limit was 0.8 ×10^-4 μg/L, and the recovery was 94.2% to 93.5%.This method is simple, rapid and accurate.