摘要
本文采用紫外-可见分光光度法对衡水湖周边小麦中铅含量进行了测定,对小麦样品进行炭化、灰化、消化处理,利用Pb-XO-CTMAB形成的三元络合物,在最佳测定波长580nm,溶液酸度pH=6.0条件下测定微量的铅,结果表明铅浓度在0-1.8mg/L范围内具有良好的线性关系,符合朗伯比尔定律,回归方程为y=0.05304x-9.52381×10^(-5),相关系数R为0.99461,摩尔吸光系数为1.02×10~4L/(mol·cm^(-1)),显色剂用量为4.00mL,CTMAB用量为5.00mL时测定结果最好。该方法具有仪器简单,操作方便;污染小,快捷经济,相对误差小等优点,并且具有一定的选择性。
This article adopted UV-VIS spectrophotometry to determine the Pb content in the wheat surrounding the Hengshui lake,treated the wheat sample as carbonization,ashing and slaking,determined the microcrystalline Pb using the ternary complexes which was formed by Pb-XO-CTMAB,under the condition of the optimal determining wavelength was 580 nm and the solution acidity was pH=6.0,the result showed that the Pb concentration had good linear relation when it was between 0-1.8mg/L,conformed to the lambert beer law,regression equation was y=0.05304x-9.52381×10^(-5),correlation coefficient R was 0.99461,molar absorption coefficient was 1.02×10~4L/(mol·cm^(-1)),color developing agent dosage was 4.00 mL,testing result was best when the CTMAB dosage was 5.00 mL.This method has the advantages of simple apparatus,easy operation,less pollution,faster and economic,small relative error,etc,and has certain selectivity.
