title: Solid-phase purification and extraction for the determination of trace neonicotinoid pesticides in tea infusion.
abstract: An analytical protocol that includes solid-phase purification and extraction is successfully developed for the determination of trace neonicotinoid pesticides in tea infusion. The method consists of a purification on amino-functionalized mesoporous silica SBA-15 followed by a solid-phase extraction based on graphene oxide before ultra high performance liquid chromatography with tandem mass spectrometry analysis. Parameters that significantly affected the extraction of the neonicotinoids onto graphene oxide, such as the amount of adsorbent, extraction time, pH, elution solvent, etc. were optimized. The amino-functionalized mesoporous silica SBA-15 has been proved to be an efficient adsorbent for removal of polyphenols especially catechins from tea infusion. Graphene oxide exhibits a very rapid adsorption rate (within 10 min) and high adsorption capacities for neonicotinoids at low initial concentration (0.01-0.5 mg/L). The analysis method gave a good determination coefficient (r(2) > 0.99) for each pesticide and high recoveries in the range of 72.2-95.0%. Powder X-ray diffraction, Raman spectroscopy, transmission electron microscopy, and UV-vis spectroscopy were utilized to identify the structure and morphology of graphene oxide. The adsorption driving force of neonicotinoids on graphene oxide mainly depends on π-π electron donor-acceptor interaction and electrostatic interaction.
authors.affiliation: Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.|Graduate School of Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Minglu
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.|Key Laboratory of Tea Quality and Safety & Risk Assessment, Ministry of Agriculture, Hangzhou, China.
authors.forename: Hongping
authors.initials: H
authors.lastname: Chen
authors.affiliation: Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.|Key Laboratory of Tea Quality and Safety & Risk Assessment, Ministry of Agriculture, Hangzhou, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.|Key Laboratory of Tea Quality and Safety & Risk Assessment, Ministry of Agriculture, Hangzhou, China.
authors.forename: Chuanpi
authors.initials: C
authors.lastname: Wang
authors.affiliation: Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.|Key Laboratory of Tea Quality and Safety & Risk Assessment, Ministry of Agriculture, Hangzhou, China.
authors.forename: Guicen
authors.initials: G
authors.lastname: Ma
authors.affiliation: Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.|Key Laboratory of Tea Quality and Safety & Risk Assessment, Ministry of Agriculture, Hangzhou, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
mesh_terms: D002851:Chromatography, High Pressure Liquid; D010575:Pesticides / Q000032:analysis / Q000302:isolation & purification*; D012822:Silicon Dioxide / Q000737:chemistry; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*; D053719:Tandem Mass Spectrometry; D013662:Tea / Q000737:chemistry*
chemical_list: D010575:Pesticides; D013662:Tea; D012822:Silicon Dioxide
keywords: Dispersive solid-phase extraction; Graphene oxide; Mesoporous silica; Neonicotinoid pesticides; Tea infusion