title: Determination of pesticides in water by cone-shaped membrane protected liquid phase microextraction prior to micro-liquid chromatography.
abstract: A new sample pre-treatment technique termed cone-shaped membrane liquid phase microextraction (CSM-LPME) was developed and combined with micro-liquid chromatography (micro-LC) for the determination of selected pesticides in water samples. Four pesticides (hexaconazole, procymidone, quinalphos and vinclozolin) were considered as target analytes. Several important extraction parameters such as types of extraction solvent, agitation rate, pH value, total exposure time and effect of salt and humic acids were optimized. Enrichment factors of > 50 folds were easily achieved within 20 min of extraction. The analytical data demonstrated relative standard deviations for the reproducibility of the optimized CSM-LPME method ranging from 6.3 to 7.5%. The correlation coefficients of the calibration curves were at least 0.9995 across a concentration range of 2-100 microg/L. The detection limits for all the analytes were found to be in the range of 1.1-1.9 microg/L.
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia. marsin@kimia.fs.utm.my
authors.forename: M Marsin
authors.initials: MM
authors.lastname: Sanagi
authors.forename: H H
authors.initials: HH
authors.lastname: See
authors.forename: Wan Aini Wan
authors.initials: WA
authors.lastname: Ibrahim
authors.forename: Ahmedy Abu
authors.initials: AA
authors.lastname: Naim
mesh_terms: D053000:Analytic Sample Preparation Methods / Q000379:methods*; D001643:Bridged Bicyclo Compounds / Q000302:isolation & purification; D002853:Chromatography, Liquid / Q000379:methods*; D006812:Humic Substances; D006863:Hydrogen-Ion Concentration; D008832:Microchemistry / Q000295:instrumentation / Q000379:methods*; D009946:Organothiophosphorus Compounds / Q000302:isolation & purification; D010080:Oxazoles / Q000302:isolation & purification; D010575:Pesticides / Q000032:analysis*; D015203:Reproducibility of Results; D014230:Triazoles / Q000302:isolation & purification; D035501:Uncertainty; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D001643:Bridged Bicyclo Compounds; D006812:Humic Substances; D009946:Organothiophosphorus Compounds; D010080:Oxazoles; D010575:Pesticides; D014230:Triazoles; D014874:Water Pollutants, Chemical; C009145:quinalphos; C035988:procymidone; C025643:vinclozolin; C409722:hexaconazole