title: The use of silica-coated magnetic graphene microspheres as the adsorbent for the extraction of pyrethroid pesticides from orange and lettuce samples followed by GC-MS analysis.
abstract: Graphene-grafted ferroferric oxide microspheres were used as the adsorbent to extract some pyrethroid pesticides (bifenthrin, λ-cyhalothrin, cyfluthrin, cypermethrin, fenvalerate, and deltamethrin) from orange and lettuce samples prior to their determination by GC-MS. The main variables that could affect the extraction, including the amount of the adsorbent, pH of the sample solution, extraction time, concentration of salt, and desorption conditions, were investigated and optimized. Under the optimized conditions, a linear response was obtained in the concentration range of 0.3-100.0 ng/g for the analytes with the coefficients of determination ranging from 0.9877 to 0.9925. The LODs for the pyrethroids ranged from 0.01 to 0.02 ng/g. The method provided a good repeatability with RSDs < 10.6%. The recoveries for the six pyrethroid pesticides were in the range from 90.0 to 103.7%. The method was applied to the determination of the pesticides in orange and lettuce samples with a satisfactory result.
authors.affiliation: Department of Chemistry, College of Science, Agricultural University of Hebei, Baoding, China.
authors.forename: Mengying
authors.initials: M
authors.lastname: Hou
authors.forename: Xiaohuan
authors.initials: X
authors.lastname: Zang
authors.forename: Chun
authors.initials: C
authors.lastname: Wang
authors.forename: Zhi
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D032084:Citrus sinensis / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D006108:Graphite / Q000737:chemistry*; D018545:Lactuca / Q000737:chemistry*; D060526:Magnetic Fields; D008863:Microspheres; D010316:Particle Size; D010573:Pesticide Residues / Q000302:isolation & purification*; D011722:Pyrethrins / Q000302:isolation & purification*; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D010573:Pesticide Residues; D011722:Pyrethrins; D012822:Silicon Dioxide; D006108:Graphite
keywords: Food samples; GC-MS; Graphene; Magnetic SPE; Pyrethroid pesticides