title: Rapid and effective sample clean-up based on magnetic multiwalled carbon nanotubes for the determination of pesticide residues in tea by gas chromatography-mass spectrometry.
abstract: In this work, amine-functionalised magnetic nanoparticles and multiwalled carbon nanotubes (MNPs/MWCNTs) composites were synthesised by a simple method and applied as an adsorbent for rapid clean-up of acetonitrile extracts of tea samples prior to analysing eight pesticide residues by gas chromatography-mass spectrometry. Several parameters affecting the sampling and treatment efficiency were investigated, including extraction solvent, sonication time, weight ratio of MWCNTs to MNPs in the composites, amount of adsorbent, clean-up time and washing solution. Under the optimised conditions, the recoveries obtained for each pesticide ranged from 72.5% to 109.1% with relative standard deviations lower than 12.6%. Limit of quantification ranged from 0.02 to 0.08 mg kg⁻¹. The established method was successfully applied to the analysis of pesticide residues in real tea samples. The results indicated that the use of MNPs/MWCNTs composites allowed the simple and expeditious clean-up of complex tea samples for subsequent determination of pesticide residues.
authors.affiliation: School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China; Analysis Center, Tianjin University, Tianjin 300072, China. Electronic address: dxj@tju.edu.cn.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Deng
authors.forename: Qianjin
authors.initials: Q
authors.lastname: Guo
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Chen
authors.forename: Tao
authors.initials: T
authors.lastname: Xue
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Pei
authors.initials: P
authors.lastname: Yao
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D000327:Adsorption; D053000:Analytic Sample Preparation Methods; D028241:Camellia sinensis / Q000737:chemistry*; D002681:China; D003959:Diamines / Q000737:chemistry; D005506:Food Contamination; D005513:Food Inspection / Q000379:methods; D008401:Gas Chromatography-Mass Spectrometry; D057927:Hydrophobic and Hydrophilic Interactions; D007202:Indicators and Reagents / Q000737:chemistry; D057230:Limit of Detection; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010573:Pesticide Residues / Q000032:analysis* / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013010:Sonication; D013499:Surface Properties; D013662:Tea / Q000737:chemistry*
chemical_list: D000097:Acetonitriles; D003959:Diamines; D007202:Indicators and Reagents; D058185:Magnetite Nanoparticles; D037742:Nanotubes, Carbon; D010573:Pesticide Residues; D012997:Solvents; D013662:Tea; C032159:acetonitrile; C007297:1,6-diaminohexane
keywords: Cleanup; Gas chromatography–mass spectrometry; Magnetic multiwalled carbon nanotubes; Pesticide residues; Tea samples