title: Determination of herbicides paraquat, glyphosate, and aminomethylphosphonic acid in marijuana samples by capillary electrophoresis.
abstract: In this work, two methods were developed to determine herbicides paraquat, glyphosate, and aminomethylphosphonic acid (AMPA) in marijuana samples by capillary electrophoresis. For paraquat analysis, sample was extracted with aqueous acetic acid solution and analyzed by capillary zone electrophoresis with direct UV detection. The running electrolyte was 50 mmol/L phosphate buffer (pH 2.50). For glyphosate and AMPA, indirect UV/VIS detection was used, as these substances do not present chromophoric groups. Samples were extracted with 5 mmol/L hydrochloric acid. The running electrolyte was 10 mmol/L gallic acid, 6 mmol/L TRIS, and 0.1 mmol/L CTAB (pH = 4.7). The methods presented good linearity, precision, accuracy, and recovery. Paraquat was detected in 12 samples (n = 130), ranging from 0.01 to 25.1 mg/g. Three samples were positive for glyphosate (0.15-0.75 mg/g), and one sample presented AMPA as well. Experimental studies are suggested to evaluate the risks of these concentrations to marijuana user.
authors.affiliation: Poison Control Center, State University of Campinas, Campinas, SP, 13083-887, Brazil.
authors.forename: Rafael
authors.initials: R
authors.lastname: Lanaro
authors.forename: José L
authors.initials: JL
authors.lastname: Costa
authors.forename: Silvia O S
authors.initials: SO
authors.lastname: Cazenave
authors.forename: Luiz A
authors.initials: LA
authors.lastname: Zanolli-Filho
authors.forename: Marina F M
authors.initials: MF
authors.lastname: Tavares
authors.forename: Alice A M
authors.initials: AA
authors.lastname: Chasin
mesh_terms: D002188:Cannabis / Q000737:chemistry*; D004340:Drug Contamination; D019075:Electrophoresis, Capillary; D005998:Glycine / Q000031:analogs & derivatives* / Q000032:analysis; D006540:Herbicides / Q000032:analysis*; D007555:Isoxazoles; D063065:Organophosphonates / Q000032:analysis*; D010269:Paraquat / Q000032:analysis*; D013777:Tetrazoles; D000097797:Glyphosate
chemical_list: D005998:Glycine; D006540:Herbicides; D007555:Isoxazoles; D063065:Organophosphonates; D010269:Paraquat; D013777:Tetrazoles; D000097797:Glyphosate; C418233:2-amino-3-(3-hydrox-5(2-methyl-2H-tetrazol-5-yl)isoxazol-4-yl)propionic acid
keywords: AMPA; Cannabis; capillary electrophoresis; forensic science; forensic toxicology; glyphosate; marijuana; paraquat