Method development for preconcentration and determination of mercury in water and air

Abstract

The method for preconcentration and determination of trace mercury in water and air were developed. MCM-41 and silica gel chemically functionalized with 2-(3-(2-aminoethylthio)propylthio)ethanamine were synthesized and used as selective adsorbents for mercury. The functionalized silica gel was further applied to a fully automated sample preconcentration and cold vapor introduction, which was coupled to an atomic absorption spectrometer. The performance of the system was investigated under optimum conditions using the spiked sample containing 0.20 and 4.00 g L-1. The percentage recovery and the precision (%RSD) of the method were in the range of 85 – 106 % and 5.5 - 12 %, respectively. The accuracy of the proposed method was tested by using certified reference materials (HG95-3 and HG 95-10) and the method gave the analytical results with acceptable accuracy.An automated atmospheric mercury analyzer based on the dielectric barrier discharge (DBD) atomic emission technique was developed. Several types of radiation detector were investigated. The system was operated continuously over 7 days to test the system performance. The limit of detection was 0.12 ng L-1 and the linear range extended at least to 6.6 ng L-1, typical RSD values for determination at the single digit ng L-1 level ranged from 2.8 to 4.9 %. The system was successfully applied to determine the atmospheric mercury at fluorescence lamp recycling plant area.