文档介绍：Abstract
The measurement of mercury in aqueous solutions by ICP-AES is adversely affected by the memory effect wherein mercury accumulates within the sample introduction system and is slowly released over time to give increasing response signals at the same initial mercury concentration. The memory effect is obviated by the addition of Hg(II) complexants: thiourea and gold(III) chloride are both effective in preventing mercury sorption and vapor buildup with the latter being preferred because the memory effect vanishes more rapidly. Conditions are described wherein it is possible to quantify low levels of mercury(II) in aqueous solutions by ICP-AES under routine operating conditions that can be applied to other metal ions by adding 1 mg of gold(III) chloride per 3 mg of mercury(II) to those solutions.
1. Introduction
The toxicity of mercury at very low levels has led to its stringent control with a maximum contaminant level of 2 μg/L being set by the US Environmental Protection Agency [1]. This has led to the development of techniques for accurate monitoring of mercury levels [2] via cold vapor atomic absorption spectrometry [3,4], plasma atomic emission spectrometry [5], atomic fluorescence spectrometry [6,7], inductively coupled plasma (ICP) optical emission spectrometry [8] and ICP-mass spectrometry [9-11]. Despite methods with good