微波消解-吸附伏安法测定大米中的铅  

Determination of Lead in Rice by Microwave Digestion-Adsorptive Voltammetry

作　　者：黎国兰[1] 周广林[1] 吕红贵[1] 杨涛[1] 顾声音[1] 

机构地区：[1]绵阳师范学院化学与化学工程学院,四川绵阳621000

出　　处：《绵阳师范学院学报》2010年第8期36-39,48,共5页Journal of Mianyang Teachers＇ College

摘　　要：Pb（Ⅱ）在硫酸铵-二甲酚橙体系中出现一灵敏的络合物吸附波,其峰电位E=-0.495 V,还原电流二阶导数I＂p与Pb（Ⅱ）浓度在2.0×10^-7-6.0×10^-5mol·L^-1范围内线性良好,回归方程为I＂p=0.828×1014CPb（mol·L^-1）＋2.22×10^9,相关系数为r=0.9990;最小检出浓度为1.0×10^-7mol·L^-1。采用微波消解法预处理大米样品,测得其中铅平均含量为0.130μg·g^-1,回收率在96.0%-103.1%之间。In ammonium sulphate - OX aqueous solution, Pb （ Ⅱ） shows a sensitive adsorptive wave with potential of -0.495V. In a cathodic sweep, the second derivative of the peak current is directly proportional to the concentration of lead in the range of 1.0 ×10^ - 7 to 6.0 ×10^ - 5 mol · L^ - 1. The standard curve equation is I＂p =0. 828 × 1014CPb（mol · L^ - 1 ） ＋ 2.22 × 10^9 with a correlation coefficient of 0. 9990, and the detection limit is 2.0 ×10^ - 7 mol ·L ^- 1. The established method has been applied to determine the lead in rice which is pretreated with microwave digestion, and the average content of lead of 0.13 μg·g^-1 is found with the recovery ranged from 96 % to 103.1%.

关 键 词：Pb(Ⅱ) 络合物吸附波 大米 微波消解 

分 类 号：O657.14[理学—分析化学]