title: [Determination of trace mercury in wastewater by a flow injection analysis composed of immobilized ionic liquid enrichment and colorimetric detection].
abstract: Amberlite XAD-7 resin was modified by room temperature ionic liquid (1-hexyl-3-methylimidazolium hexafluorophosphate, [C6 mim]PF6) coating through a maceration method, gaining a new sort of hydrophobic adsorbent for the solid phase extraction mini-column. Trace inorganic mercury in wastewater samples was preconcentrated and determined by flow injection online mini-column sampling coupled with spectrophotometric determination. In acid medium, dithizone was employed as chelator with cetyltrimethylammonium bromide (CTMAB) to form a red neutral mercury-dithizone complex, which could be extracted quantificationally by solid phase extraction technique on the mini-column. Under the optimized conditions, the linearity and the detection limit of the proposed method were found to be 0.35 to 50.0 microg x L(-1) Hg2+ and 0.067 microg x L(-1) Hg2+, respectively. The enrichment factor of 25 times could be achieved with a 50 mL sampling volume and the developed procedure was successfully applied for the determination of mercury in the certified reference material (GSBZ50016-90) and the spiked dock wastewater samples with the recovery of 99%-103%.
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China. nedzhang@163.com
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Li-li
authors.initials: LL
authors.lastname: Mao
authors.forename: Gui-peng
authors.initials: GP
authors.lastname: Yang
authors.forename: Xian-chi
authors.initials: XC
authors.lastname: Gao
authors.forename: Xu-li
authors.initials: XL
authors.lastname: Tang