Recent advances in electrochemical detection of toxic Cr(vi)

Abstract

Large quantities of highly toxic hexavalent chromium (Cr(VI)) compounds are often discharged from waste streams into the environment from various industrial processes. As stated by the World Health Organization (WHO), a maximum limit of 50 μg L⁻¹ hexavalent chromium in groundwater system has been set for human and environmental concerns. Therefore, reliable and convenient monitoring of Cr(VI) is significantly important and emergent. Recently, electrochemical detection of hexavalent chromium has been proven as one of the most efficient methodologies and attracted increasing interest since it offers high sensitivity and powerful information, inherent miniaturization, cost-effectiveness and compatibility with advanced microfabrication technologies. This review comments on recent achievements in the electrode materials and detection techniques for electrochemical quantification of hexavalent chromium, and outlines key challenges and opportunities in the further improvement and applications. Emphasis especially focuses on the developments of mercury, bismuth, carbon and gold based electrode materials. It is expected that these novel electrochemical detection systems will succeed in on-site Cr(VI) measurements with excellent performance, reliable and convenient measurement, low cost and environmental effectiveness.