示差脉冲溶出伏安法测定食品中的硒

Determination of Se in Food by Differential Pulse Cathodic Stripping Voltammetry

应用悬汞电极溶出伏安法(DPCSV)测定食品中的硒,测定底液为MgCl_2-HCl,含微量Cu(Ⅱ),硒的检测限为0.21ppb(称样量2g时,食品中检测限约为0.01ppm),六次平行测定的变异系数为5.3％。以本法测定5份不同种类食品中的硒含量,其回收率为93％115％。

A prosedure for determination of Se in food by differential pulse cathodic stripping voltammetry (DPCSV) at the handing mercury drop electrode has been established. The sample is digested dryly with HNO3 - Mg(NO3)2. In MgCl2 - HC1 medium (with minor Cu(II), pH-1), the detection limit for Se is 0. 21ppb (0. 01ppm for 2g food), the coefficient of variative is 5. 39% .The procedure has been applied to deteimine Se in five kinds of food, the average recovery for Se are 93% -115% respectively.