title: Determination of Hg(2+) by on-line separation and pre-concentration with atmospheric-pressure solution-cathode glow discharge atomic emission spectrometry.
abstract: A simple and sensitive method to determine Hg(2+) was developed by combining solution-cathode glow discharge atomic emission spectrometry (SCGD-AES) with flow injection (FI) based on on-line solid-phase extraction (SPE). We synthesized l-cysteine-modified mesoporous silica and packed it in an SPE microcolumn, which was experimentally determined to possess a good mercury adsorption capacity. An enrichment factor of 42 was achieved under optimized Hg(2+) elution conditions, namely, an FI flow rate of 2.0 mL min(-1) and an eluent comprised of 10% thiourea in 0.2 mol L(-1) HNO3. The detection limit of FI-SCGD-AES was determined to be 0.75 μg L(-1), and the precision of the 11 replicate Hg(2+) measurements was 0.86% at a concentration of 100 μg L(-1). The proposed method was validated by determining Hg(2+) in certified reference materials such as human hair (GBW09101b) and stream sediment (GBW07310).
authors.affiliation: Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.affiliation: Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050, China; School of Materials Science and Engineering, Shanghai University, Shanghai 200072, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050, China. Electronic address: wangzheng@mail.sic.ac.cn.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D001274:Atmospheric Pressure; D004566:Electrodes; D008628:Mercury / Q000032:analysis*; D012996:Solutions; D013054:Spectrophotometry, Atomic / Q000295:instrumentation*; D013499:Surface Properties
chemical_list: D012996:Solutions; D008628:Mercury
keywords: Mercury; Mesoporous silica; Separation and pre-concentration; Solid-phase extraction; Solution-cathode glow discharge