铬天青S分光光度法测定一次性纸杯中的铅

Spectrophotometric Determination of Lead from Disposable Paper Cup

在以0.50 mol/L HNO_3作为介质、溴化十六烷基三甲基胺作为表面活性剂的条件下,利用铬天青S (CAS)与Pb^(2+)反应生成红褐色络合物,从而建立一种测定重金属铅的分光光度法。Pb^(2+)-CAS络合物的最大吸收峰在500nm处, Pb^(2+)的浓度在0～0.96μg/mL之间与吸光度存在良好的线性关系,线性方程为A=0.228 3c+0.401 5。以一次性纸杯作为分析样品,样品经过灰化和酸溶,测定一次性纸杯中的铅。结果表明,该方法灵敏度高,稳定性好,试验简单,易于操作,测定结果令人满意。

Chrome azurol S(CAS)and Pb2+reaction is used as a brown complex in the condition,which is determined in nitric acid as the medium and cetyltrimethylammonium bromide(CTMAB)as the surfactant.A method for determination of Pb2+is established by spectrophotometer.In optical condition,and the maximum absorption peak of Pb2+-CAS complex is located at 500 nm.A good linearity ranged from 0-0.96μg/mL of Pb2+and absorbance,and the liner equation is A=0.228 3 c+0.401 5.The disposable paper cups are ashed and dissolved by acid,to determinate the Pb2+.The results show high sensitivity and good stability.The experiment process is simple and easy to operate,and the determination results are satisfied.