[Determination of 20 kinds of pesticide residues in soybeans and corn using gas chromatography-negative chemical ionization mass spectrometry coupled with offline disperse solid-phase extraction].
A method was developed for the determination of 20 kinds of pesticide residues in soybeans and corn with the technique of offline disperse solid-phase extraction and gas chromatography-negative chemical ionization mass spectrometry (GC-NCI/MS). The pesticides interested were extracted twice from the samples with acetonitrile. The combined extract was concentrated to dryness and redissolved in acetonitrile, then cleaned up by dispersive solid-phase extraction with sorbents of N-propyl ethylene diamine (PSA), graphited carbon black, and C18, and determined and confirmed by GC-NCI/MS. The recoveries of all pesticides were in the range of 70%-130% at three spiked levels (5, 10 and 20 microg/kg), and the relative standard deviations were below than 17%. The linearity of the method was good in the concentration range of 20-400 microg/L, and limits of quantification (LOQs) were no more than 2 microg/kg. The method is selective well with no interference and suitable for the confirmatory of pesticide residues in soybeans and corn.
Li
Chunfeng
C
Institute of Veterinary Drug, Huazhong Agricultural University, Wuhan 430070, China.
Shen
Weijian
W
Jiang
Yuan
Y
Shen
Chongyu
C
Zhao
Zengyun
Z
Yu
Keyao
K
Gui
Qianwen
Q
Sun
Ningning
N
Yuan
Zonghui
Z
D005506:Food Contamination / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D010573:Pesticide Residues / Q000032:analysis*; D052616:Solid Phase Extraction / Q000379:methods*; D013025:Glycine max / Q000737:chemistry*; D003313:Zea mays / Q000737:chemistry*
D010573:Pesticide Residues