title: Trace determination of dichlorvos in environmental samples by room temperature ionic liquid-based dispersive liquid-phase microextraction combined with HPLC.
abstract: Using 1-butyl-3-methylimidazolium hexaﬂuorophosphate ([BMIM][PF6]) room temperature ionic liquid (RTIL) as extraction solvent, tetrahydrofuran (THF) as disperser solvent, the organophosphorus pesticide dichlorvos in water was determined by dispersive liquid-liquid microextraction (DLLME) combined with high-performance liquid chromatography. Factors affecting RTIL-DLLME (type of disperser solvent, amount of RTIL, volume of disperser solvent, percentage of NaCl and volume and pH of water sample) were optimized by the single-factor method, obtaining the most favorable results when using 65 µL of [BMIM][PF6] and 260 µL of THF to extract the compound from an 8-mL water sample at pH 5.0 containing 25% (w/v) of NaCl. Under these optimum conditions, an enrichment factor of 215-fold was obtained. The calibration curves were linear in the concentration range of 2-1,000 µg/L. The limit of detection calculated at a signal-to-noise ratio of 3 was 0.2 µg/L. The relative standard deviations (RSD) for six replicate experiments at 20, 100 and 200 µg/L concentration levels were 1.8%, 1.3% and 1.3 %, respectively. Then the proposed method was applied to the analysis of three different water sample sources (tap, farm and rain water) and the relative recoveries and RSD of spiked water samples were 95.6-102.4% and 0.6-3.1%, respectively, at three different concentration levels of 20, 100 and 200 µg/L.
authors.affiliation: Center for Instrumental Analysis, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, China Pharmaceutical University, 210009 Nanjing, People's Republic of China. wangsonghui198604@163.com
authors.forename: Songhui
authors.initials: S
authors.lastname: Wang
authors.forename: Bingren
authors.initials: B
authors.lastname: Xiang
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Tang
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004006:Dichlorvos / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D060766:Drinking Water / Q000737:chemistry; D005663:Furans / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles / Q000737:chemistry; D059627:Liquid Phase Microextraction / Q000379:methods*; D010573:Pesticide Residues / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D011891:Rain / Q000737:chemistry; D015203:Reproducibility of Results; D012965:Sodium Chloride / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification
chemical_list: C412621:1-butyl-3-methylimidazolium hexafluorophosphate; D060766:Drinking Water; D005663:Furans; D007093:Imidazoles; D010573:Pesticide Residues; D014874:Water Pollutants, Chemical; C018674:tetrahydrofuran; D012965:Sodium Chloride; D004006:Dichlorvos