title: Simultaneous determination of three residual barbiturates in pork using accelerated solvent extraction and gas chromatography-mass spectrometry.
abstract: A new method was developed for the rapid extraction and unequivocal determination of barbital, amobarbital and phenobarbital residues in pork. The isolation of the analytes from pork samples was accomplished by utilizing an accelerated solvent extractor ASE 300. The procedure was automatically carried out in series for fat removing and extraction, respectively with n-hexane and acetonitrile pressurized constantly at 10.3 MPa for 30 min. After evaporation, the extracts were cleaned up on a C(18) solid phase extraction (SPE) cartridge and the barbiturates were eluted with hexane-ethyl acetate (7:3), evaporated on a rotary evaporator and derivatized with CH(3)I. The methylated barbiturates were separated on a HP-5MS capillary column and detected with a mass detector. Electron impact ion source (EI) operating in time program-selected ion monitoring mode (SIM) was used for identification and external standard method was used for quantification. Good linearity was obtained in the range from 0.5 microg/kg to 25 microg/kg. Average recoveries of the three barbiturates spiked in pork ranged from 84.0% to 103.0%, with relative standard deviations from 1.6% to 12%. The limit of detection (LOD) was 0.5 microg/kg for the three barbiturates (S/N>or=3). The quantification limit (LOQ) was 1 microg/kg for the three barbiturates (S/N>or=10).
authors.affiliation: Inspection Technology and Equipment Institute, Chinese Academy of Inspection and Quarantine, Beijing 100025, China.
authors.forename: Haixiang
authors.initials: H
authors.lastname: Zhao
authors.forename: Liping
authors.initials: L
authors.lastname: Wang
authors.forename: Yueming
authors.initials: Y
authors.lastname: Qiu
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Zhou
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.forename: Weike
authors.initials: W
authors.lastname: Zhong
mesh_terms: D000818:Animals; D001463:Barbiturates / Q000032:analysis*; D002138:Calibration; D004350:Drug Residues / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D008461:Meat Products / Q000032:analysis*; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012997:Solvents; D013552:Swine
chemical_list: D001463:Barbiturates; D012997:Solvents