Determination of low concentrations of acetochlor in water by automated solid-phase extraction and gas chromatography with mass-selective detection

• Published in: Journal of AOAC International Vol. 79; no. 4; pp. 962 - 966
• Main Authors: Lindley, C.E. (U.S. Geological Survey, Denver, CO.), Stewart, J.T, Sandstrom, M.W
• Format: Journal Article
• Language: English
• Published: Gaithersburg, MD AOAC International 01-07-1996
• Subjects: AGUA SUPERFICIAL; AGUAS SUBTERRANEAS; ANALISIS CUANTITATIVO; ANALYSE QUANTITATIVE; Analytical chemistry; AUTOMATISATION; AUTOMATIZACION; CALIDAD DEL AGUA; Chemistry; Chromatographic methods and physical methods associated with chromatography; CHROMATOGRAPHIE EN PHASE GAZEUSE; CONTAMINACION; CONTAMINATION; CROMATOGRAFIA DE GASES; EAU SOUTERRAINE; EAU SUPERFICIELLE; ESPECTROMETRIA DE MASAS; EVALUACION; EVALUATION; Exact sciences and technology; Gas chromatographic methods; HERBICIDAS; HERBICIDE; MEDICION; MESURE; POLLUTION DE L'EAU; POLUCION DEL AGUA; QUALITE DE L'EAU; SPECTROMETRIE DE MASSE; Trace analysis; Water; Gas chromatography; Solid phase extraction; Chemical analysis; Coupled method; Chlorine Organic compounds; Pesticides; Acetamide; Mass spectrometry; Herbicide
• ISSN: 1060-3271; 1944-7922
• DOI: 10.1093/jaoac/79.4.962

A sensitive and reliable gas chromatographic/mass spectrometric (GC/MS) method for determining acetochlor in environmental water samples was developed. The method involves automated extraction of the herbicide from a filtered 1 L water sample through a C18 solid-phase extraction column, elution from the column with hexane-isopropyl alcohol (3 + 1), and concentration of the extract with nitrogen gas. The herbicide is quantitated by capillary/column GC/MS with selected-ion monitoring of 3 characteristic ions. The single-operator method detection limit for reagent water samples is 0.0015 microgram/L. Mean recoveries ranged from about 92 to 115% for 3 water matrixes fortified at 0.05 and 0.5 microgram/L. Average single-operator precision, over the course of 1 week, was better than 5%