Graphene as dispersive solidphase extraction materials for pesticides LC-MS/MS multi-residue analysis in leek, onion and garlic.
A multi-residue analytical method was validated for 24 representative pesticides residues in onion, garlic and leek. The method is based on modified QuEChERS sample preparation with a mixture of graphene, primary secondary amine (PSA), and graphitised carbon black (GCB) as reversed-dispersive solid-phase extraction (r-DSPE) material and LC-MS/MS. Graphene was first used as an r-DSPE clean-up sorbent in onion, garlic and leek. The results first show that the mixed sorbent of graphene, PSA and GCB has a remarkable ability to clean-up interfering substances in the r-DSPE procedure when compared with the mixture of PSA and GCB. Use of matrix-matched standards provided acceptable results for tested pesticides with overall average recoveries between 70.1% and 109.7% and consistent RSDs <15.6%. In any case, this method still meets the 1-10 μg kg(-1) detection limit needed for pesticide testing and may be used for qualitative screening applications in which any identified pesticides can be quantified and confirmed by a more intensive method that achieves >70% recovery.
a College of Science , China Agricultural University , Beijing 100193 , China.
Wenbi
W
Guan
Changsheng
C
Li
Xue
X
Liu
Shujing
S
Zhou
Yongqiang
Y
Ma
D000490:Allium / Q000737:chemistry*; D002853:Chromatography, Liquid / Q000379:methods*; D006108:Graphite / Q000737:chemistry*; D010573:Pesticide Residues / Q000737:chemistry; D010575:Pesticides / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
D010573:Pesticide Residues; D010575:Pesticides; D006108:Graphite