title: Micro-scale membrane extraction of glyphosate and aminomethylphosphonic acid in water followed by high-performance liquid chromatography and post-column derivatization with fluorescence detector.
abstract: A carrier-mediated supported liquid membrane micro-extraction using single hollow fiber membrane suitable for the determination of the herbicide glyphosate and its main metabolite aminomethylphosphonic acid in water is reported. A solution of 0.20 M Aliquat-336, a cationic carrier, in di-n-hexyl ether was selected as the supported liquid. A 20 microL of 1.0 M potassium chloride as the acceptor phase was filled in the membrane lumen. The membrane was immersed in a 20 mL of pH 9.0 sample solution. After 60-min extraction, the acceptor phase was analyzed by high-performance liquid chromatography with post-column derivatization. The enrichment factors were found to be 853 and 136 for glyphosate and aminomethylphosphonic acid, respectively. The method detection limits are 0.22 microg/L for glyphosate and 3.40 microg/L for aminomethylphosphonic acid. The procedure was validated and showed good accuracy and precision over a large linear dynamic range. The validated method was tested for the analysis of both analytes in spiked groundwater with good success.
authors.affiliation: Chromatography and Separation Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Montra
authors.initials: M
authors.lastname: Piriyapittaya
authors.forename: Siripastr
authors.initials: S
authors.lastname: Jayanta
authors.forename: Somenath
authors.initials: S
authors.lastname: Mitra
authors.forename: Natchanun
authors.initials: N
authors.lastname: Leepipatpiboon
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D005998:Glycine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification; D007555:Isoxazoles; D015394:Molecular Structure; D063065:Organophosphonates / Q000737:chemistry / Q000302:isolation & purification*; D015203:Reproducibility of Results; D013050:Spectrometry, Fluorescence / Q000379:methods; D013777:Tetrazoles; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*; D000097797:Glyphosate
chemical_list: D005998:Glycine; D007555:Isoxazoles; D063065:Organophosphonates; D013777:Tetrazoles; D014874:Water Pollutants, Chemical; D000097797:Glyphosate; C418233:2-amino-3-(3-hydrox-5(2-methyl-2H-tetrazol-5-yl)isoxazol-4-yl)propionic acid