氢化物发生-原子荧光光谱法测定大米与圆白菜中痕量铅

建立了氢化物发生-原子荧光光谱法(HG-AFS)测定经HNO3-HClO4-H2O2湿法消解的大米与圆白菜等样品中痕量铅的方法,系统地优化了灯电流等仪器参数条件,探讨了载流、还原剂、样品酸度、氧化剂的最佳浓度,考察了掩蔽剂去干扰的情况。实验表明:在选定载流浓度HCl 2%(V/V)、还原剂KBH4浓度2%(m/V)KOH恒为0.5%(m/V)]、样品酸度HCl 1%(V/V)、氧化剂K3Fe(CN)60.4%(m/V)、掩蔽剂H2C2O40.2%(m/V)及优化设置灯电流等参数的最佳实验条件下,测定铅的检出限为0.07μg/L,在0.00—50.00μg/L范围呈良好的线性关系,样品测定变异系数小于等于6.22%。该方法简便、干扰少、灵敏度高,应用于大米、圆白菜等样品中Pb的测定,结果与参考值相符,是一种切实可行的方法。

Determination of Lead in Rice and Cabbage by Hydride Generation-Atomic Fluorescence Spectrometry

Rice and cabbage samples were dissolved by HNO3-HClO4-H2O2.Then,the concentration of lead(Pb) was determined by hydride generation-atomic fluorescence spectrometry(HG-AFS) with the best experimental conditions and instrumental settings,including the concentrations of carrier flow(HCl 2%),reducer(KBH4 2%+KOH 0.5%),the acidity of samples(HCl 1%),oxidantK3Fe(CN)6 0.4%],screen(H2C2O4 0.2%) and the best settings of AFS.Under the optimal experimental conditions,the detection limits of Pb is 0.07μg/L,it was greatly linear during 0.00 and 50.00μg/L,and the C.V.of the sample was less than 6.22%.Therefore,the method characterized by convenience,high efficiency and high precision could be applied to determine Pb in rice and cabbage,and the results were accordant with the standard value.