Novel Field Sampling Procedure for the Determination of Methiocarb Residues in Surface Waters from Rice Fields

• Published in: Journal of agricultural and food chemistry 2001-12, Vol.49 (12), p.5706-5709
• Main Authors: Primus, Thomas M, Kohler, Dennis J, Avery, Mike, Bolich, Pat, Way, M. O, Johnston, John J
• Format: Article
• Language: English
• Subjects: Agriculture - methods; Agronomy. Soil science and plant productions; Animals; Applied sciences; Biological and medical sciences; Chromatography, High Pressure Liquid; Continental surface waters; Diptera; Exact sciences and technology; Fishes; Fundamental and applied biological sciences. Psychology; Methiocarb - analysis; Methiocarb - toxicity; Natural water pollution; Oncorhynchus mykiss; Oryza; Pesticide Residues - analysis; Pesticide Residues - toxicity; Pollution; Soil and water pollution; Soil science; Water; Water treatment and pollution
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf010540v

Methiocarb was extracted from surface water samples collected at experimental rice field sites in Louisiana and Texas. The sampling system consisted of a single-stage 90-mm Empore extraction disk unit equipped with a battery-powered vacuum pump. After extraction, the C-18 extraction disks were stored in an inert atmosphere at −10 °C and shipped overnight to the laboratory. The disks were extracted with methanol and the extracts analyzed by reversed-phase high-performance liquid chromatography with a methanol/water mobile phase. Methiocarb was detected by ultraviolet absorption at 223 nm and quantified with the use of calibration standards. Recoveries from control surface water samples fortified at 5.0, 10, 50, and 100 ng/mL methiocarb averaged 92 ± 7%. A method limit of detection for methiocarb in rice field surface water was estimated to be 0.23 ng/mL at 223 nm. Keywords: Methiocarb; mesurol; high-performance liquid chromatography; solid phase extraction disks; water