洗涤剂中铅测定方法的改进

针对干灰化法消解样品时存在的问题进行了改进,加入硝酸镁和氧化镁克服了干灰化法低温灰化不完全、高温灰化存在损失的缺点。对氢化物发生-原子吸收光谱法测定铅的酸度介质条件进行了研究,确定了pH在1.5～2.5范围内的最适宜的酸度条件,优化了氢化物原子吸收法测定日用化学品中铅的条件。试验方法经实测,铅检出限为0.4μg/L,定量下限为1.2μg/L。样品加标测定的相对标准偏差RSD为2.5%,铅的回收率范围为93%～102%。

An Improved Detecting Method on the Determination of Lead in Detergents

By adding magnesium nitrate and magnesium oxide to improve the dry ashing method,the new method overcame incomplete digestion at lower temperature and loss at higher temperature.The effects of acidity to the determination of lead were studied.In order to ensure the determination,the acidity was adjusted with sodium hydroxide.Optimized condition of determination of lead with hydride generation atomic absorption spectrometry was investigated.The detection limit for lead was 0.4 μg/L,the minimum quantitative detection limit was 1.2 μg/L,the relative standard deviation of standard addition method in sample was 2.5%,the recovery was 93% to 102%.