Determination of residues of 446 pesticides in fruits and vegetables by three-cartridge solid-phase extraction-gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry.
A method was developed for determination of residues of 446 pesticides in fruits and vegetables through the use of cleanup by a 3-cartridge solid-phase extraction-gas chromatography/ mass spectrometry (GC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS). Fruit and vegetable samples (20 g) were extracted with 40 mL acetonitrile, salted out, and centrifuged. Half of the supernatant was passed into an Envi-18 cartridge, eluted with acetonitrile, and cleaned up with Envi-Carb and aminopropyl Sep-Pak cartridges in series after concentration of the eluates. Pesticides were eluted with acetonitrile-toluene (3 + 1, v/v), and eluates were concentrated to 0.5 mL and then added into internal standards after solvent exchange with 2 mL hexane and used for determination of 383 pesticides by GC/MS. The other half of the supernatant was concentrated to 1 mL and cleaned up with Envi-Carb and aminopropyl Sep-Pak cartridges in series. Pesticides were eluted with acetonitrile-toluene (3 + 1, v/v), and the eluates were concentrated to 0.5 mL, dried with nitrogen gas, diluted to 1.0 mL with acetonitrile-water (3 + 2, v/v), and used for determination of 63 pesticides by LC/MS/MS. The limit of detection for the method was 0.2-600 ng/g depending on the individual pesticide. In the method, fortification recovery tests at high, medium, and low levels were conducted on 6 varieties of fruits and vegetables, i.e., apples, oranges, grapes, cabbage, tomatoes, and celery, with average recoveries falling within the range of 55.0-133.8% for 446 pesticides, among which average recoveries between 60.0-120.0% accounted for 99% of the results. The relative standard deviation was between 2.1-39.1%, of which a relative standard deviation of 2.1-25.0% made up 96% of the results. Experiments proved that the method was applicable for determination of residues of 446 pesticides in fruit and vegetables.
Pang
Guo-Fang
GF
Qinhuangdao Entry-Exit Inspection and Quarantine Bureau, 39 Haibin Rd, Qinhuangdao, Hebei, PC 066002, People's Republic of China. gfpang@heinfo.net
Fan
Chun-Lin
CL
Liu
Yong-Ming
YM
Cao
Yan-Zhong
YZ
Zhang
Jin-Jie
JJ
Li
Xue-Min
XM
Li
Zeng-Yin
ZY
Wu
Yan-Ping
YP
Guo
Tong-Tong
TT
D000097:Acetonitriles / Q000494:pharmacology; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002853:Chromatography, Liquid / Q000379:methods*; D005506:Food Contamination; D005638:Fruit / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006586:Hexanes / Q000032:analysis; D013058:Mass Spectrometry / Q000379:methods*; D009584:Nitrogen; D010573:Pesticide Residues / Q000032:analysis*; D010575:Pesticides / Q000032:analysis* / Q000302:isolation & purification; D012015:Reference Standards; D015203:Reproducibility of Results; D012997:Solvents; D014050:Toluene / Q000032:analysis / Q000737:chemistry; D014675:Vegetables / Q000378:metabolism*
D000097:Acetonitriles; D006586:Hexanes; D010573:Pesticide Residues; D010575:Pesticides; D012997:Solvents; D014050:Toluene; D009584:Nitrogen; C032159:acetonitrile