Validation study on 660 pesticide residues in animal tissues by gel permeation chromatography cleanup/gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry.
A new method using gel permeation chromatography (GPC) cleanup followed by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS-MS) has been established for quantitative determination of 437 pesticide residues in animal tissues such as beef, mutton, pork, chicken, and rabbit. Based on an appraisal of the characteristics of both GC-MS and LC-MS-MS, validation experiments were conducted for 660 pesticides. In the method, 10 g animal samples were mixed with 20 g sodium sulfate and extracted with 35 mL of cyclohexane+ethyl acetate (1+1) twice by blender homogenization, centrifugation, and filtration. Evaporation was conducted and an equivalent of 5 g sample was injected into a 400 mm x 25 mm S-X3 GPC column, with cyclohexane+ethyl acetate (1+1) as the mobile phase at a flow rate of 5 mL/min. The 22-40 min fraction was collected for subsequent analysis. For the 368 pesticides determined by GC-MS, the portions collected from GPC were concentrated to 0.5 mL and exchanged with 5 mL hexane twice. For the 69 pesticides by LC-MS-MS, the portions collected from GPC were dissolved with acetonitrile+water (60+40) after taking the extract to dryness with nitrogen gas. In the linear range of each pesticide, the correlation coefficient was r > or = 0.98, exceptions being dinobuton, linuron, and fenamiphos sulfoxide. At the low, medium and high three fortification levels of 0.2-4800 microg/kg, recoveries fell within 40-120%, among which 417 pesticides recoveries between 60% and 120%, accounting for 95%, 20 analytes between 40% and 60%, accounting for 5%. The relative standard deviation was below 28% for all 437 pesticides. The limits of detection for the method were 0.2-600 microg/kg, depending on each pesticide.
Pang
Guo-Fang
GF
Qinhuangdao Entry-Exit Inspection and Quarantine Bureau, 39 Haibin Road, Qinhuangdao, Hebei PC 066002, China. gfpang@heinfo.net
Cao
Yan-Zhong
YZ
Zhang
Jin-Jie
JJ
Fan
Chun-Lin
CL
Liu
Yong-Ming
YM
Li
Xue-Min
XM
Jia
Guang-Qun
GQ
Li
Zeng-Yin
ZY
Shi
Yu-Qiu
YQ
Wu
Yan-Ping
YP
Guo
Tong-Tong
TT
D000818:Animals; D002850:Chromatography, Gel / Q000379:methods*; D002853:Chromatography, Liquid / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods*; D010573:Pesticide Residues / Q000032:analysis* / Q000302:isolation & purification; D015203:Reproducibility of Results
D010573:Pesticide Residues