Determination of Trace Mercury in the Environmental Water Containing Iodide by Using Cold-Vapor Atomic Absorption Spectrometry

摘要

A new method for the determination of trace mercury is proposed by using cold-vapor atomic absorption analysis after the reduction of mercury with a mixture of sodium tetrahydroborate (NaBH4) and tin(II) chloride in acidic solution. Iodide up to 20mg/20ml did not interfere with the mercury determination, and 85% recovery of mercury was attained even in the presence of 100mg of iodide. The present method was successfully applied to the determination of mercury in complicated iodide-containing environmental samples such as wastewater discharged from universities, research institutes and so on. Furthermore, the mechanism of the interference of iodide in the determination of trace mercury was investigated electrochemically by pseudo-polarographic and potentiometric measurement.