title: Application of continual injection liquid-phase microextraction method coupled with liquid chromatography to the analysis of organophosphorus pesticides.
abstract: A liquid-phase microextraction coupled with LC method has been developed for the determination of organophosphorus pesticides (methidation, quinalphos and profenofos) in drinking water samples. In this method, a small amount (3 microL) of isooctane as the acceptor phase was introduced continually to fill-up the channel of a 1.5 cm polypropylene hollow fiber using a microsyringe while the hollow fiber was immersed in an aqueous donor solution. A portion of the acceptor phase (ca. 0.4 microL) was first introduced into the hollow fiber and additional amounts (ca. 0.2 microL) of the acceptor phase were introduced to replenish at intervals of 3 min until set end of extraction (40 min). After extraction, the acceptor phase was withdrawn and transferred into a 2 mL vial for a drying step prior to injection into a LC system. Parameters that affect the extraction efficiency were studied including the organic solvent, length of fiber, volume of acceptor and donor phase, stirring rate, extraction time, and effect of salting out. The proposed method provided good enrichment factors of up to 189.50, with RSD ranging from 0.10 to 0.29%, analyte recoveries of over 79.80% and good linearity ranging from 10.0 to 1.25 mg/L. The LOD ranged from 2.86 to 82.66 microg/L. This method was applied successfully to the determination of organophosphorus pesticides in selected drinking water samples.
authors.affiliation: Separation Science Research Group, Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, Johor, Malaysia.
authors.forename: Yanuardi
authors.initials: Y
authors.lastname: Raharjo
authors.forename: Mohd Marsin
authors.initials: MM
authors.lastname: Sanagi
authors.forename: Wan Aini Wan
authors.initials: WA
authors.lastname: Ibrahim
authors.forename: Ahmedy Abu
authors.initials: AA
authors.lastname: Naim
authors.forename: Hassan Y
authors.initials: HY
authors.lastname: Aboul-Enein
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation* / Q000379:methods*; D017022:Flow Injection Analysis / Q000379:methods*; D015394:Molecular Structure; D009943:Organophosphorus Compounds / Q000032:analysis* / Q000737:chemistry*; D010575:Pesticides / Q000032:analysis* / Q000737:chemistry*; D012997:Solvents; D013997:Time Factors
chemical_list: D009943:Organophosphorus Compounds; D010575:Pesticides; D012997:Solvents