粮食、血中痕量硒蛋氨酸的溴化氰——荧光测定法

Method of Cyanogen Bromide Fluorimetry Determination of Trace Amount of Selenomethionine in Grain and Blood

本法是利用溴化氰与硒蛋氨酸定量生成硒氰酸甲酯（ＣＨ３ＳｅＣＮ），ＣＨ３ＳｅＣＮ经氯仿萃取后用混合酸消化为Ｓｅ（ＩＶ），再用２，３－二氨基萘测定苤硒脑的荧光值推算硒蛋氨酸含量。本法硒蛋氨酸最低检出限为３ｎｇ／ｇ。用硒含量１０～５００ｎｇ的硒蛋氨酸标准进行测定，其回收率为９１．８％～９７．６％，相对偏差为１．９％～６．３％。样品回收率为９２．３％～９６．７％，相对偏差为２．７％～９．０％。硒胱氨酸、硒半胱氨酸、亚硒酸钠和蛋氨酸对测定无干扰。本法的精密度和准确度均较好。

Selenomethionine (SeMet)reacted with cyanogen bromide (BrCN)quantitatively forms CH 3SeCN.After extracted with CHCl 3,the Se of CH 3SeCN is acid digested to Se(IV).Then 2,3 diaminonaphthalene is used to determine the fluorescent Se value of 4,5 benzopiaselenol.The determination limit of this method was 3ng/g SeMet.The accuracy of 10￣500ng Se in SeMet standard was 91 8%￣ 97.6%. RSD was 1.9%￣6.3%.Recoveries for grain and blood were 92.3%￣96.7%. RSD was 2.7%￣5.1%. The RSD for samples was 2.7%￣9.0%.Selenocystine,selenocystiene selenite and methionine did not interfere with the determination.