title: Determination of trace mercury in water based on N-octylpyridinium ionic liquids preconcentration and stripping voltammetry.
abstract: A novel method for determination of trace mercury in water is developed. The method is performed by extracting mercury firstly with ionic liquids (ILs) and then detecting the concentration of mercury in organic media with anodic stripping voltammetry. Liquid-liquid extraction of mercury(II) ions by four ionic liquids with N-octylpyridinium cations ([OPy](+)) was studied. N-octylpyridinium tetrafluoroborate and N-octylpyridinium trifluoromethylsulfonate were found to be efficient and selective extractant for mercury. Temperature controlled dispersive liquid phase microextraction (TC-DLPME) technique was utilized to improve the performance of preconcentration. After extraction, precipitated IL was diluted by acetonitrile buffer and mercury was detected by differential pulse stripping voltammetry (DPSV) with gold disc electrode. Mercury was enriched by 17 times while interfering ions were reduced by two orders of magnitude in the organic media under optimum condition. Sensitivity and selectivity for electrochemical determination of mercury were improved by using the proposed method. Tap, pond and waste water samples were analyzed with recoveries ranging from 81% to 107% and detection limit of 0.05 μg/L.
authors.affiliation: State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Science, No. 19 North 4th Ring Road West, Haidian District, 100190 Beijing, China.
authors.forename: Zhenhan
authors.initials: Z
authors.lastname: Li
authors.affiliation: State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Science, No. 19 North 4th Ring Road West, Haidian District, 100190 Beijing, China. Electronic address: shxia@mail.ie.ac.cn.
authors.forename: Shanhong
authors.initials: S
authors.lastname: Xia
authors.affiliation: State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Science, No. 19 North 4th Ring Road West, Haidian District, 100190 Beijing, China.
authors.forename: Jinfen
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Science, No. 19 North 4th Ring Road West, Haidian District, 100190 Beijing, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Bian
authors.affiliation: State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Science, No. 19 North 4th Ring Road West, Haidian District, 100190 Beijing, China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Tong
mesh_terms: D004563:Electrochemistry; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D059627:Liquid Phase Microextraction; D059625:Liquid-Liquid Extraction; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D052578:Ionic Liquids; D014874:Water Pollutants, Chemical; D006046:Gold; D008628:Mercury
keywords: Anodic stripping voltammetry; Ionic liquid; Mercury determination; Preconcentration