标准加入法测定饲料级硫酸锌中铅的含量

Determination of the amount of lead in zinc sulfate by standard addition method

由于饲料中铅超标直接导致被饲喂动物的内脏、肌肉、骨骼中铅含量的超标,而人食用这一类的动物肌肉制品后危害极大,会造成神经系统紊乱。文章以原子吸收结合标准加入法检测饲料原料硫酸锌中铅的含量,将被检测样品溶解在稀硝酸介质中,于原子吸收分光光度计波长283.3nm处,使用空气-乙炔火焰进行测定。以铅的质量为横坐标,对应的吸光度为纵坐标,绘制工作曲线,将曲线反向延长与横轴相交处即为试样溶液中的铅含量。经试验:此方法具有重复性好、r≥0.9999、检测回收率≥99.0%、标准偏差≤0.63%等特点。

Excessive lead in feed results in high level lead in animal offal, muscle and bone, while the consumption of animal muscle tissue derivative food products does great harm on human body with nervous system damage. In this study, atomic absorption method combined with standard addition method was hired to determine the lead content in feed raw material zinc sulfate. Sample was dissolved in dilute nitric acid, and measurement was performed by flame atomic absorption spectrometry at 283.3nm. Work curve was protracted with lead content as abscissa and the corresponding absorbance as y-axis. The intersection of the curve on abscissa represents the lead content. Results indicated this method might be an ideal method for lead assay in feed additive zinc sulfate, with good reappearence, good linearity with r≥t 0.9999, RSD ≥ 0.63%, and recovery≤ 99.0%.