Measurement System of Mercury in Water Samples by Reduction Vaporization Method Using a Quartz Crystal Microbalance

Abstract

To reduce the environmental risks posed by mercury (Hg), a simple and rapid detection system for Hg in the environment is needed. We developed a simple Hg measurement method for detecting of Hg in liquid phase using quartz crystal microbalance (QCM-Hg). Mercury is reduced into Hg⁰ by adding the reducing solution (SnCl₂) to the divalent Hg²⁺ in the sample solution. Then, Hg is turned into vapor in reactor bottle by flowing air. It (QCM-Hg) utilizes the direct reaction of Hg and the Au electrode of the quartz crystal element via the phenomenon of Au-Hg amalgamation. In the case of 0.0005 mg/L in liquid phase, a frequency shift of about 13 Hz is obtained using a 20 MHz quartz crystal element. This new detection system allows easy measurement of very low concentrations of Hg in liquid phase.