title: Trace analysis of sulfonylurea herbicides in water by on-line continuous flow liquid membrane extraction--C18 precolumn liquid chromatography with ultraviolet absorbance detection.
abstract: An on-line system that consists of continuous-flow liquid membrane extraction (CFLME), C18 precolumn, and liquid chromatography with UV detection was applied to trace analysis of sulfonylurea herbicides in water. During preconcentration by CFLME, five target compounds, including metsulfuron methyl, bensulfuron methyl, tribenuron methyl, sulfometuron methyl, and ethametsulfuron, were enriched in 960 microl of 0.5 mol l(-1) Na2CO3-NaHCO3 (pH 10.8) buffer used as acceptor. This acceptor was on-line neutralized and transported to the C18 precolumn where the analytes were absorbed and focused. Then the focused analytes were injected onto a C18 analytical column for separation and detection at 240 nm. The proposed method was applied to determine sulfonylurea herbicides in water, river, and reservoir water with detection limits of 10-50 ng l(-1) when enriching a 120-ml sample. Throughput is typically one sample per hour.
authors.affiliation: Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085, China.
authors.forename: Jing-fu
authors.initials: JF
authors.lastname: Liu
authors.forename: Jing-bo
authors.initials: JB
authors.lastname: Chao
authors.forename: Gui-bin
authors.initials: GB
authors.lastname: Jiang
authors.forename: Ya-qi
authors.initials: YQ
authors.lastname: Cai
authors.forename: Jie-min
authors.initials: JM
authors.lastname: Liu
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D006540:Herbicides / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D013453:Sulfonylurea Compounds / Q000032:analysis*
chemical_list: D006540:Herbicides; D013453:Sulfonylurea Compounds