title: Development of an Analytical Method Based on Temperature Controlled Solid-Liquid Extraction Using an Ionic Liquid as Solid Solvent.
abstract: At the present paper, an analytical method based on temperature controlled solid-liquid extraction (TC-SLE) utilizing a synthesized ionic liquid, (N-butylpyridinium hexafluorophosphate, [BPy]PF₆), as solid solvent and phenanthroline (PT) as an extractant was developed to determine micro levels of Fe(2+) in tea by PT spectrophotometry. TC-SLE was carried out in two continuous steps: Fe(2+) can be completely extracted by PT-[BPy]PF₆ or back-extracted at 80 °C and the two phases were separated automatically by cooling to room temperature. Fe(2+), after back-extraction, needs 2 mol/L HNO₃ as stripping agent and the whole process was determined by PT spectrophotometry at room temperature. The extracted species was neutral Fe(PT)mCl₂ (m = 1) according to slope analysis in the Fe(2+)-[BPy]PF₆-PT TC-SLE system. The calibration curve was Y = 0.20856X - 0.000775 (correlation coefficient = 0.99991). The linear calibration range was 0.10-4.50 μg/mL and the limit of detection for Fe(2+) is 7.0 × 10(-2) μg/mL. In this method, the contents of Fe(2+) in Tieguanyin tea were determined with RSDs (n = 5) 3.05% and recoveries in range of 90.6%-108.6%.
authors.affiliation: School of Chemical and Biological Science, Quanzhou Normal University, Quanzhou, 362000, China. panzhongwei@qztc.edu.cn.|Hengxing Energy Saving Technology Company Limited of Quanzhou, Fujian 362000, China. panzhongwei@qztc.edu.cn.
authors.forename: Zhongwei
authors.initials: Z
authors.lastname: Pan
authors.affiliation: Hengxing Energy Saving Technology Company Limited of Quanzhou, Fujian 362000, China. Zhenquan2811@sohu.com.
authors.forename: Zhengquan
authors.initials: Z
authors.lastname: Wang
authors.affiliation: School of Chemical and Biological Science, Quanzhou Normal University, Quanzhou, 362000, China. 18065318102@163.com.
authors.forename: Linna
authors.initials: L
authors.lastname: Zhu
authors.affiliation: School of Chemical and Biological Science, Quanzhou Normal University, Quanzhou, 362000, China. zhuzhiming1208@sina.com.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: School of Chemical and Biological Science, Quanzhou Normal University, Quanzhou, 362000, China. 18065318218@163.com.
authors.forename: Jinying
authors.initials: J
authors.lastname: Cai
authors.affiliation: School of Chemical and Biological Science, Quanzhou Normal University, Quanzhou, 362000, China. qsebike5@pcqs-china.com.
authors.forename: Xiaoman
authors.initials: X
authors.lastname: Shen
authors.affiliation: School of Chemical and Biological Science, Quanzhou Normal University, Quanzhou, 362000, China. ftl1226@sina.com.
authors.forename: Tingli
authors.initials: T
authors.lastname: Fan
authors.affiliation: School of Chemical and Biological Science, Quanzhou Normal University, Quanzhou, 362000, China. 18759966957@163.com.
authors.forename: Yingnan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Chemical and Biological Science, Quanzhou Normal University, Quanzhou, 362000, China. zhixiu.chen@outlook.com.
authors.forename: Zhixiu
authors.initials: Z
authors.lastname: Chen
mesh_terms: D002138:Calibration; D002413:Cations, Divalent; D006801:Humans; D052578:Ionic Liquids / Q000737:chemistry; D007501:Iron / Q000032:analysis*; D057230:Limit of Detection; D059625:Liquid-Liquid Extraction / Q000379:methods*; D017942:Nitric Acid / Q000737:chemistry; D010618:Phenanthrolines / Q000737:chemistry*; D011726:Pyridinium Compounds / Q000737:chemistry; D052616:Solid Phase Extraction / Q000379:methods*; D013053:Spectrophotometry / Q000379:methods*; D013662:Tea / Q000737:chemistry*
chemical_list: D002413:Cations, Divalent; D052578:Ionic Liquids; D010618:Phenanthrolines; D011726:Pyridinium Compounds; D013662:Tea; D017942:Nitric Acid; C046365:n-butylpyridinium; D007501:Iron
keywords: determination of Fe2+; ionic liquid as solid solvent; tea; temperature controlling solid-liquid separation