微量荧光法测定粮食样品中痕量硒－与原荧光法的比较

Comparison between microfluorescence method and fluorescence method in determination of selenium in cereals samples

微量荧光法测定粮食样品中痕量硒，最低检出限为０．３ｎｇ，是原荧光法１／１０；多次测定含硒１５～３９２ｎｇ／ｇ的粮食样品加硒标回收率为９０．６％～９９．３％，对牛肝粉及奶粉标准参考物的测定值均在保证值范围之内；测定含硒１７～２９８ｎｇ／ｇ的粮食样品，变异系数为２．１％～２．６％。另外，微量法还减少了样品及试剂用量，为原法的１／１０，并且省去了原法中去硒硫酸的制备，不仅大大降低了成本，减轻了工作量，而且降低了酸对人体健康的影响和对环境造成的污染。

The microflurescence method is more sensitive than the fluorescence method in the determination of selenium in cereals. The minimum detectable amount is 0. 3ng which is one-tenth of that by fluorescence method. The microfluorescence method is accurate. The recovery rate is 90.6%～99.3%, when samples contain 15 ～ 392ng selenium. The determination vaiue of standard reference materials of bovine liver and milk is in the reference valve. The coefficient of variation is 2.1%～5.4%. Using the method, the quantity of samples as well as reagents can be saved. The preparation of non-selenium sulphuric acid is not required.Less cost and work are needed. This method reduces the hazard caused by acid.