DITHIOCARBAMATE EXTRACTION AND AU(III) BACK-EXTRACTION FAR DETERMINATION OF MERCURY IN WATER AND BIOLOGICAL SAMPLES BY ANODIC-STRIPPING VOLTAMMETRY

A novel method employed for determining trace mercury in water and biological samples was developed in the study. The mercury was preconcentrated from the water samples and the digested biological samples through means of diethyldithiocarbamate extraction in conjunction with AU(3+) back extraction. The preconcentrated solution, which simply contained the enriched mercury ion with the possible transition-metal ions and nonreacted AU(3+), was next transferred to an electrochemical cell for detecting mercury via differential pulse anodic stripping voltammetry (DPASV) through the usage of a gold film carbon electrode. AU(3+) was selected as a back-extracting agent in light of its standing as highest extraction constant with diethyldithiocarbamate, being greater than that of Hg2+. Besides, the excess nonreacted Au3+ in the preconcentrated solution could be used in situ as the source of generating the gold film of the working electrode in the DPASV. Sufficient evidence of high feasibility in the determination of mercury for different water samples was provided in this present work. Reliability and accuracy of this novel method were confirmed from the NBS biological standard reference materials analysis.