Investigating the surface of solid gold electrode to improve the sensitivity of anodic stripping voltammetry for arsenic detection

摘要

Arsenic (As) is now recognized to be one of the world's greatest environmental hazards, threatening the lives of several hundred million people (Meharg, 2005; Raven-scroft et al., 2009). Natural As contamination now affects more than 70 countries in the world, however, the worst situation is in Bangladesh, where more than 50 million (Meharg, 2005; Ravenscroft et al., 2009) of people are drinking water contaminated with As above 10 μg/L, which is WHO safe limit set in 1993. It is crucial to be able to monitor As in groundwater and in particular in Bangladesh to provide people with information which tube wells are safe to drink from and which are not to reduce their exposure to high levels of As. However, even the most advance methods of analysis for inorganic As such as inductively coupled plasma mass spectrometry (ICP-MS), atomic absorption spectrometry with hydride generation (AAS-HG) or graphite furnace (AAS-GF) still have problems with accurate detection of low levels of As, especially in saline matrix and when other elements such as chromium, vanadium, cadmium and platinum are present. In addition such methods are only laboratory based methods, require complicated infrastructure, trained chemists and are very expensive, especially for countries such as Bangladesh. There is however, another method which has recently provided an alternative to the ICP-MS and AAS-HG methods.