Determination of lead and cadmium in high salt condiment via anodic stripping voltammetry

A method was studied for determination of lead and cadmium in high salt condiment,such as dampened spicy,soy sauce and fish sauce,by the combination of wet digestion and stripping voltammetry.The impact of the instrument conditions,the type and amount of electrolyte and high salt on lead and cadmium was investigated,and the experiment was made on the disturbance of acid type and acidity as well as other coexisting ions. The linear range of the working curves of Pb and Cd are 2~50 μg·L^-1and 1~20 μg·L^-1respectively,the correlation coefficient were 0.9999 and 1.0000,and their instrument detection limits were 0.043 μg·L^-1and 0.029 μg·L^-1,their method detection limits were Pb 2.17 μg·kg^-1,Cd 1.43 μg·kg^-1.The content of lead and cadmium about actual sample was determined by this method,the precisions are respectively 1.11% ~ 4.66%,0.69% ~ 5.34%. The recovery rate were respectively 93.9% ~109.9%,94.7% ~ 107.5%. The result reveals that this was a simple,fast and higher sensitivity method which had a good selection and excellent reliability.