title: Simultaneous determination of cypermethrin and permethrin in pear juice by ultrasound-assisted dispersive liquid-liquid microextraction combined with gas chromatography.
abstract: A new method was developed for simultaneous determination of cypermethrin and permethrin residues in pear juice with ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) and gas chromatography-flame ionization detection (GC-FID). 3.5 mL of methanol (dispersant) and 30 microL of C(2)Cl(4) (extractant) were injected into 5.0 mL of pear juice sample and then emulsified by ultrasound for 2.0 min to forming the cloudy solution. Under the optimum condition, the enrichment factors for cypermethrin and permethrin were 344 and 351 fold respectively. Good linearity was observed in a range of 0.009-1.52 microg g(-1) with the correlation coefficient (r(2))>or=0.9993. The limits of detection (LODs) were 3.1 and 2.2 microg kg(-1) for cypermethrin and permethrin, respectively (S/N=3). The recoveries of the method evaluated at three spiked levels were in the range of 92.1%-107.1%. The repeatability evaluated as intra-day and inter-day precision (RSDs) were less than 4.0% (n=5). The developed method was successfully applied to determine the two pesticide residues in different pear juice samples.
authors.affiliation: College of Pharmaceutical Sciences, Hebei University, Baoding, China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Du
authors.forename: Hongyuan
authors.initials: H
authors.lastname: Yan
authors.forename: Dandan
authors.initials: D
authors.lastname: She
authors.forename: Baomi
authors.initials: B
authors.lastname: Liu
authors.forename: Gengliang
authors.initials: G
authors.lastname: Yang
mesh_terms: D001628:Beverages; D002849:Chromatography, Gas / Q000379:methods; D006863:Hydrogen-Ion Concentration; D007306:Insecticides / Q000032:analysis; D026023:Permethrin / Q000032:analysis*; D011722:Pyrethrins / Q000032:analysis*; D031989:Pyrus / Q000737:chemistry*; D052617:Solid Phase Microextraction / Q000379:methods; D014465:Ultrasonics
chemical_list: D007306:Insecticides; D011722:Pyrethrins; C017160:cypermethrin; D026023:Permethrin