非完全消化—悬浮液进样—FAAS测定饲料中镁、锌、铜

Determination of Magnesium,Zinc and Copper in Feed by Incomplete Digestion-Suspension Sampling-FAAS

将饲料样品烘干、粉碎和过筛,在加热条件下用浓硝酸消解样品,使绝大部分样品组分(95%以上)进入溶液,再加入乳化剂聚乙二醇辛基苯基醚(OP),将其悬浮在1.5 g/L 5 mL琼脂溶液中制成非完全消化悬浮液,以氧化镧(La2O3)作为释放剂以消除化学干扰。用火焰原子吸收法光谱法成功测定了饲料中的镁、锌、铜微量元素,测定结果的相对标准偏差小于3.0%。试验结果与灰化法一致,此方法简便、快速、准确。

Feed samples were baked out,crushed,sifted and then digested with high concentration nitric acid on condition of heating until the solution became transparent,finally suspended in 1.5 g/L 5mL agar solution,and so made into incompletely digested suspension.Magnesium,zinc and copper were determined by flame atomic absorption spectrometry（FAAS）,using La2O3 as release reagent to eliminate chemical interference.Results： The relative standard deviations are less than 3.0%.The determination data are consistent with the ashing method.This method is simple,fast and accurate.