Arsenic determination by the silver diethyldithiocarbamate method and the elimination of metal ion interferences

Several metal ions--chromium, cobalt, copper, mercury, molybdenum, and antimony--have been reported to interfere in the determination of arsenic in water and waste water by the Silver Diethyldithiocarbamate (SDDC) method, but the limit of interference by each ion has never been precisely evaluated. Conflicting reports have also appeared in the literature on the role of chromium and antimony as interfering ions in this method. The present study was undertaken to resolve the confusion that surrounds the use of the SDDC method for the determination of arsenic in water and waste water.