Trace element determination of mercury by total-reflection X-ray fluorescence

Abstract

A rapid and simple method is presented for the determination of trace amounts of ionic mercury in solutions by total-reflection X-ray fluorescence. The method relies on the formation of a mercury amalgam on a 50 nm thick silver coating deposited on a specular-surface quartz reflector. Quantification of Hg in dilute HNO3 solutions is achieved, with a straight calibration line in the concentration range 50–350 ng ml−1. With excitation by a molybdenum anode X-ray tube at 40 kV and 20 mA, the limit of detection achieved for a 2 cm3 specimen with 1000 s counting time is 15 ng ml−1.