title: Preparation of a graphene-based magnetic nanocomposite for the extraction of carbamate pesticides from environmental water samples.
abstract: A graphene-based magnetic nanocomposite was synthesized and used for the first time as an effective adsorbent for the preconcentration of the five carbamate pesticides (metolcarb, carbofuran, pirimicarb, isoprocarb and diethofencarb) in environmental water samples prior to high performance liquid chromatography-diode array detection. The properties of the magnetic nanocomposite were characterized by scanning electron microscopy and X-ray diffraction. This novel graphene-based magnetic nanocomposite showed great adsorptive ability towards the analytes. The method, which takes the advantages of both nanoparticle adsorption and magnetic phase separation from the sample solution, could avoid some of the time-consuming experimental procedures related to the traditional solid phase extraction. Various experimental parameters that could affect the extraction efficiencies have been investigated. Under the optimum conditions, the enrichment factors of the method for the analytes were in the range from 474 to 868. A linear response was achieved in the concentration range of 0.1-50 ng mL(-1). The limits of detection of the method at a signal to noise ratio of 3 for the pesticides were 0.02-0.04 ng mL(-1). Compared with the dispersive liquid-liquid microextraction and the ultrasound-assisted surfactant-enhanced emulsification microextraction, much higher enrichment factors and sensitivities were achieved with the developed method. The method has been successfully applied for the determination of the carbamate pesticides in environmental water samples.
authors.affiliation: Key Laboratory of Bioinorganic Chemistry, College of Science, Agricultural University of Hebei, Baoding 071001, Hebei, China.
authors.forename: Qiuhua
authors.initials: Q
authors.lastname: Wu
authors.forename: Guangying
authors.initials: G
authors.lastname: Zhao
authors.forename: Cheng
authors.initials: C
authors.lastname: Feng
authors.forename: Chun
authors.initials: C
authors.lastname: Wang
authors.forename: Zhi
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D002219:Carbamates / Q000032:analysis / Q000302:isolation & purification*; D005591:Chemical Fractionation / Q000295:instrumentation* / Q000379:methods; D002851:Chromatography, High Pressure Liquid; D006108:Graphite / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D059346:Magnets / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites / Q000737:chemistry*; D010575:Pesticides / Q000032:analysis / Q000302:isolation & purification*; D015203:Reproducibility of Results; D045483:Rivers / Q000737:chemistry; D012680:Sensitivity and Specificity; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification; D014881:Water Supply
chemical_list: D002219:Carbamates; D010575:Pesticides; D014874:Water Pollutants, Chemical; D006108:Graphite