title: Accelerated Solvent Extraction of Insecticides from Rice Hulls, Rice Bran, and Polished Rice Grains.
abstract: Analysis of pesticide residues in irrigated rice grains is important for food security. In this study, we analyzed accelerated solvent extraction (ASE) conditions for the extraction of thiamethoxam and chlorantraniliprole insecticides from rice hulls, rice bran, and polished rice grains. Several variables, including extraction solvent, extraction temperature, extraction pressure, cell size, static extraction time, and sample concentration, were investigated. The average recoveries of the three matrixes were between 89.7 and 109.7% at the fortification level of 0.75 mg/kg. The optimum ASE operating conditions were acetonitrile (100%) as extraction solvent, extraction temperature of 75°C for rice hulls and 100°C for rice bran and polished rice grains, extraction cell pressure of 10.3 MPa, 22 mL cell size, and two extraction cycles. The total extraction time was approximately 25 min. The extracted volume was evaporated to dryness and the residues were redissolved in 2 mL acetonitrile after 1 min of vortex-shaking. Thiamethoxam and chlorantraniliprole were analyzed by ultra-HPLC with tandem MS. In conclusion, ASE in rice hulls, rice bran, and polished rice grains offers the possibility of a fast and simple method for obtaining a quantitative extraction of the studied pesticides.
authors.affiliation: Universidade Federal de Santa Maria, Department of Plant Science, Santa Maria, RS, Brazil.
authors.forename: Gustavo Mack
authors.initials: GM
authors.lastname: Teló
authors.affiliation: University of Tennessee, Department of Plant Sciences, Knoxville, TN.
authors.forename: Scott Allen
authors.initials: SA
authors.lastname: Senseman
authors.affiliation: Universidade Federal de Santa Maria, Department of Plant Science, Santa Maria, RS, Brazil.
authors.forename: Enio
authors.initials: E
authors.lastname: Marchesan
authors.affiliation: Universidade Federal de Pelotas, Department of Crop Protection, Pelotas, RS, Brazil.
authors.forename: Edinalvo Rabaioli
authors.initials: ER
authors.lastname: Camargo
authors.affiliation: Texas A&M University, Department of Soil and Crop Sciences, College Station, TX.
authors.forename: Katherine
authors.initials: K
authors.lastname: Carson
mesh_terms: D000096:Acetone / Q000737:chemistry; D000097:Acetonitriles / Q000737:chemistry; D000399:Air Pressure; D005591:Chemical Fractionation; D002851:Chromatography, High Pressure Liquid; D006586:Hexanes / Q000737:chemistry; D007306:Insecticides / Q000032:analysis*; D057230:Limit of Detection; D000432:Methanol / Q000737:chemistry; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000032:analysis*; D012275:Oryza / Q000737:chemistry*; D010078:Oxazines / Q000032:analysis*; D012997:Solvents; D053719:Tandem Mass Spectrometry; D013696:Temperature; D000077922:Thiamethoxam; D013844:Thiazoles / Q000032:analysis*; D062367:ortho-Aminobenzoates / Q000032:analysis*
chemical_list: D000097:Acetonitriles; D006586:Hexanes; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; D010078:Oxazines; D012997:Solvents; D013844:Thiazoles; D062367:ortho-Aminobenzoates; D000096:Acetone; C517733:chlorantranilipole; D000077922:Thiamethoxam; D000432:Methanol; C032159:acetonitrile