超声辅助离子液体分散液液微萃取-反相液相色谱法测定水中丁醚脲残留

Determination of Diafenthiuron Residue in Water by Ultrasound-assisted Ionic Liquid Dispersive Liquid-Liquid Microextraction-Reversed Phase Liquid Chromatography

建立了超声辅助离子液体分散液液微萃取-反相液相色谱法分析水中丁醚脲残留的新方法。采用疏水性离子液体1-辛基-3-甲基咪唑六氟磷酸盐([OMIM]PF6)为萃取剂,乙腈为分散剂。考察了萃取剂和分散剂的种类及体积,超声、静置、离心时间,溶液pH值及盐度等因素对萃取效果和富集倍数的影响。使用Hypersil C18柱(200 mm×4.6mm i.d.,5μm ODS C18)液相色谱分离测定萃取液,流动相为100%甲醇、流速0.8mL/min、柱温25℃、检测波长为245nm。在优化实验条件下,丁醚脲的富集倍数、线性范围和检出限分别为358、0.01～1.0mg/L和0.8μg/L。运用此方法成功测定了实际水样(自来水、地下水、矿泉水)中的丁醚脲,样品的加标回收率和相对标准偏差(n=6)分别为81%～98%和1.2%～8.9%。

A novel method for the determination of diafenthiuron residue in water was developed using ultrasonic-assisted ionic liquid dispersive liquid- liquid microextraction -reversed phase liquid chromatography. The hydrophobic 1-octoyl-3-methylimidazolium hexafluorophosphate ionic liquid （[OMIM] PF6） and acetonitrile were used as extraction and dispersive reagents, respectively. Effects of experimental factors, such as volumes and types of extraction reagent and dispersive reagent, ultrasonic time, standing time and centrifugation time, pH and salinity of solution, were investigated. The extract was separated and determined by LC with a Hypersil C18 column（200 mm ×4.6 mmi. d. , 5 μm ODS C18 ）. 100% of methanol was used as mobile phase with a flow rate of 0. 8 mL/min, the column temperature was set at 25 ℃, and the detection wavelength was set at 245 nm. Under the optimized conditions, the enrichment factor, linear range and detection limit for diafenthiuron were 358, 0. 01 - 1.0 mg/L and 0. 8μg/L, respectively. The proposed method was successfully applied in the determination of diafenthiuron in real water samples （ tap water, groundwater and mineral water）, and the spiked recoveries were in the range of 81% - 98% with relative standard deviations（n =6） of 1.2% -8.9% .