Abstract:
By using a hyphenated solid phase extraction (SPE) and solid phase spectroscopy designed by our group, a rapid, sensitive and selective method for detecting Hg
2+ in river water is developed. Hg-dithizone produced with dithizone and Hg
2+ can be enriched on a mixed cellulose membrane, and the residual dithizone was removed by washing the membrane with sodium hydroxide solution. Then, visible diffuse reflectance spectroscopy was used for the quantitative analysis of Hg
2+ in situ. As such, unwanted interference from other contaminants was minimized by washing the membrane to remove dithizone; EDTA disodium is also added to mask Cu
2+ and Cd
2+. Under the optimal conditions, the liner range of the method is 0.5−30 μg/L with a squared correlation coefficient of 0.993, and the limit of detection is 0.444 μg/L. The method is applied to the quantification of Hg
2+ in tap-water and river water. The recovery rates achieve 91.3%−108.0%, and the relative standard deviations of parallel tests range from 2.06 to 9.68. This work offers a fast method for the determination of Hg
2+ in river water with high sensitivity and selectivity.