title: Novel pipette-tip graphene/poly (vinyl alcohol) cryogel composite extractor for the analysis of carbofuran and carbaryl in water.
abstract: A novel pipette-tip extractor of a graphene/poly (vinyl alcohol) cryogel (graphene/PVA) composite sorbent was prepared to preconcentrate carbamate pesticides in environmental water samples before analysis with a gas chromatograph-flame ionization detector (GC-FID). This novel pipette-tip extractor with the graphene/PVA sorbent exhibited a high porosity when observed through a scanning electron micrograph (SEM). Under optimal conditions, using only 1.0 mL of sample and 0.75 mL of eluting solvent, the developed method provided a wide linear range of 10-700 ng mL(-1) and 10-500 ng mL(-1) with limit of detection (LOD) of 6.40 ± 0.18 and 9.17 ± 0.34 ng mL(-1) for carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate) and carbaryl (1-naphthyl methylcarbamate), respectively. The pipette-tip extractor provided high extraction efficiency with high accuracy indicated, by good recoveries in the range of 74.5 ± 4.8% to 119.7 ± 1.6% and 76 ± 15% to 114 ± 19% for carbofuran and carbaryl, respectively. In addition, the fabrication procedure showed a good pipette-tip extractor-to-pipette-tip extractor reproducibility with a relative standard deviation of 1.3-9.8% (n = 5). When the developed pipette-tip extractor was applied for the extraction of carbofuran and carbaryl in surface water samples near vegetable plantation areas, 25.9 ± 8.2 ng mL(-1) of carbofuran was found, and carbaryl was also detected in concentrations that ranged from 45.0 ± 4.0 to 191 ± 13 ng mL(-1).
authors: a Higher Education Research Promotion and National Research University Project of Thailand , Prince of Songkla University , Hat Yai , Songkhla , Thailand.
authors: Kanokrat
authors: K
authors: Charoenpornpukdee
authors: Chongdee
authors: C
authors: Thammakhet
authors: Panote
authors: P
authors: Thavarungkul
authors: Proespichaya
authors: P
authors: Kanatharana
mesh_terms: D065966:Absorption, Physicochemical; D000327:Adsorption; D012721:Carbaryl / Q000032:analysis*; D002235:Carbofuran / Q000032:analysis*; D059985:Cryogels; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods; D005410:Flame Ionization; D006108:Graphite; D011142:Polyvinyl Alcohol; D015203:Reproducibility of Results; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D059985:Cryogels; D014874:Water Pollutants, Chemical; D006108:Graphite; D011142:Polyvinyl Alcohol; D012721:Carbaryl; D002235:Carbofuran
keywords: Carbamate pesticides; cryogel; graphene; pipette-tip extractor