title: Study on the determination of heavy metals in water samples with ultrasound-assisted dispersive liquid-liquid microextraction prior to FAAS.
abstract: A new, simple and rapid method based on dispersive liquid-liquid microextraction (DLLME) was developed for extracting and preconcentrating copper (Cu), nickel (Ni), lead (Pb) and cadmium (Cd) in water samples prior to flame atomic absorption spectrometry (FAAS) analysis. 1-(2-thiazolylazo)-naphthol (TAN) was used as chelating reagents, and non-ionic surfactant Triton X-114 and CCl(4) as disperser solvent and extraction solvent, respectively. Some influential factors relevant to DLLME, such as the concentration of TAN, type and volume of disperser and extraction solvent, pH and ultrasound time, were optimized. Under the optimal conditions, the calibration curve was linear in the range of 10-800 μg L(-1) for Cu and Ni, 10-500 μg L(-1) for Pb, and 10-1,000 μg L(-1) for Cd, respectively. The limits of detection for the four metal ions were below 0.5 μg L(-1), with the enhancement factors of 105, 66, 28 and 106 for Cu, Ni, Pb and Cd, respectively. The relative standard deviations (RSD, n = 6) were 2.6-4.1%. The proposed method was applied to determination of Cu, Ni, Pb and Cd in water samples and satisfactory relative recoveries (93.0-101.2%) were achieved.
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, Yunnan Province 650500, China.
authors.forename: Zonghao
authors.initials: Z
authors.lastname: Li
authors.forename: Gong
authors.initials: G
authors.lastname: Yu
authors.forename: Jun
authors.initials: J
authors.lastname: Song
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.forename: Mousheng
authors.initials: M
authors.lastname: Liu
authors.forename: Yaling
authors.initials: Y
authors.lastname: Yang
mesh_terms: D001391:Azo Compounds / Q000737:chemistry; D002251:Carbon Tetrachloride / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007477:Ions; D059627:Liquid Phase Microextraction / Q000379:methods*; D019216:Metals, Heavy / Q000032:analysis*; D017830:Octoxynol; D011092:Polyethylene Glycols / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013054:Spectrophotometry, Atomic / Q000379:methods*; D013997:Time Factors; D014465:Ultrasonics / Q000379:methods*; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D001391:Azo Compounds; D007477:Ions; D019216:Metals, Heavy; D012997:Solvents; D014874:Water Pollutants, Chemical; D014867:Water; C054556:1-(2-thiazolylazo)-2-naphthol; D011092:Polyethylene Glycols; D017830:Octoxynol; C010615:Nonidet P-40; D002251:Carbon Tetrachloride