Direct determination of selenium in whole blood by anodic stripping voltammetry

Trace quantities of selenium can be determined in the presence of iron, copper and lead using anodic stripping voltammetry, depositing at -0.60 V in 0.1 M HClO4 and stripping in the anodic direction. Two separate peaks are observed at -0.25 V and -0.10 V belonging to copper and selenium, respectively. Sometimes one peak may be observed for both copper and selenium. In this case one more stripping (without deposition) must be done to obtain separate peaks. After standard addition, two strippings have to be done also. With this proposed method, 10(-7) M selenium could be determined as (1.09 +/- 0.03) x 10(-7) M with a 90% confidence interval in blood samples without any separation.