Determination of Cr(VI) Content in Leather with Anodic Stripping Voltammetric Polargraphy

摘要

An anodic stripping voltammetric method has been developed for determination of Cr(VI) content in leather treated with nitric acid-hydrogen peroxide microwave digestion. Microwave digestion was used in sample preparation for its fast digestion, lower reagent consumption and safe operation. The sample solution was mixed with DTPA (diethylenetriaminepentaacetic acid)-sodium acetate-sodium nitrate buffer solution, and then it was purged with oxygen free nitrogen for 300 seconds before deposition of the metals was carried out by applying a constant potential versus Ag/AgCI to the hanging mercury drop electrode (HMDE) for 60 seconds. A standard addition procedure was used for quantification. The repeatability and recovery percentage were tested to evaluate the determination methods. The results showed that Cr(VI) content in leather sample determined was 0.68mg/kg. Relative standard deviations for 8 replicate determinations of 5ug/L Cr(VI) standard solution and leather samples were carried out and the precision test results were 1.338 and 7.47% respectively. Recovery percentage was in the range from 97.22% to 106.58%. The proposed method is simple, convenient, sensitive and reliable.