title: Preparation and characterization of amino functionalized nano-composite material and its application for multi-residue analysis of pesticides in cabbage by gas chromatography-triple quadrupole mass spectrometry.
abstract: In this paper, a novel and recyclable amino-functionalized nano-composite material (NCM) using tetraethylenepentamine (TEPA) as a coupling agent was synthesized. The properties of the TEPA-NCM were characterized by transmission electron microscopy (TEM), Fourier transform infrared analysis (FTIR), thermogravimetric analysis (TGA) and elemental analysis (EA). An effective dispersive solid-phase extraction (dSPE) procedure using the TEPA-NCM was developed, and comparative studies were carried out among Carbon/NH₂ SPE, primary secondary amine (PSA) dSPE and TEPA-NCM dSPE. The results showed that TEPA-NCM dSPE was faster, easier and more effective to clean and enrich than the Carbon/NH₂ cartridges, and the TEPA-NCM was much more effective to remove the pigments in vegetable samples than the PSA materials. The TEPA-NCM could be reused at least five times without much sacrifice of the cleanup efficiency. Furthermore, a gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS/MS) method was established for the simultaneous determination of 29 pesticides (such as organochlorine and organophosphorus pesticides) in vegetables by dSPE using acetonitrile as an extraction solvent and TEPA-NCM as an adsorbent instead of PSA. The recoveries were in the range of 75-114% for all analytes except for trans-chlordane. The RSDs were in the range of 2-17%. The linearities were in the range of 0.4-100.0 μg/kg with determination coefficients (r²) higher than 0.986 for all compounds. The limits of detection (LODs) for all pesticides were less than 0.29 μg/kg and the limits of quantification (LOQs) were between 0.17 and 0.95 μg/kg. The developed method was applied to fifteen real vegetable samples, and it was confirmed that the TEPA-NCM was one of a kind of highly effective dSPE materials used for the pesticides analyses.
authors.affiliation: Ningbo Key Laboratory of Poison Research and Control, Ningbo Municipal Center for Disease Control and Prevention, Ningbo, Zhejiang 315010, China.
authors.forename: Yong-Gang
authors.initials: YG
authors.lastname: Zhao
authors.forename: Hao-Yu
authors.initials: HY
authors.lastname: Shen
authors.forename: Jia-Wei
authors.initials: JW
authors.lastname: Shi
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Chen
authors.forename: Mi-Cong
authors.initials: MC
authors.lastname: Jin
mesh_terms: D000327:Adsorption; D001937:Brassica / Q000737:chemistry*; D005506:Food Contamination / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D053761:Nanocomposites / Q000737:chemistry*; D010573:Pesticide Residues / Q000032:analysis* / Q000302:isolation & purification*; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods; D014675:Vegetables / Q000737:chemistry
chemical_list: D010573:Pesticide Residues