title: Optimization and validation of liquid-liquid extraction with low temperature partitioning for determination of carbamates in water.
abstract: Using a 2(3) experimental design, liquid-liquid extraction with low temperature partitioning (LLE-LTP) was optimized and validated for analysis of three carbamates (aldicarb, carbofuran and carbaryl) in water samples. In this method, 2.0 mL of sample is placed in contact with 4.0 mL of acetonitrile. After agitation, the sample is placed in a freezer for 3 h for phase separation. The organic extract is analyzed by high performance liquid chromatography with ultraviolet detection (HPLC-UV). For validation of the technique, the following figures of merit were evaluated: accuracy, precision, detection and quantification limits, linearity, sensibility and selectivity. Extraction recovery percentages of the carbamates aldicarb, carbofuran and carbaryl were 90%, 95% and 96%, respectively. Even though extremely low volumes of sample and solvent were used, the extraction method was selective and the detection and quantification limits were between 5.0 and 10.0 microg L(-1), and 17.0 and 33.0 microg L(-1), respectively.
authors.affiliation: Departamento de Química, Universidade Federal de Viçosa, Vila Gianetti, Casa 24, 36 570-000 Viçosa, MG, Brazil.
authors.forename: Simone Machado
authors.initials: SM
authors.lastname: Goulart
authors.forename: Renata Domingos
authors.initials: RD
authors.lastname: Alves
authors.forename: Antônio Augusto
authors.initials: AA
authors.lastname: Neves
authors.forename: José Humberto
authors.initials: JH
authors.lastname: de Queiroz
authors.forename: Tamires Condé
authors.initials: TC
authors.lastname: de Assis
authors.forename: Maria Eliana L R
authors.initials: ME
authors.lastname: de Queiroz
mesh_terms: D000448:Aldicarb / Q000032:analysis; D002219:Carbamates / Q000032:analysis; D012721:Carbaryl / Q000032:analysis; D002235:Carbofuran / Q000032:analysis; D005591:Chemical Fractionation / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D057230:Limit of Detection; D010573:Pesticide Residues / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D002219:Carbamates; D010573:Pesticide Residues; D014874:Water Pollutants, Chemical; D000448:Aldicarb; D012721:Carbaryl; D002235:Carbofuran