title: Water with low concentration of surfactant in dispersed solvent-assisted emulsion dispersive liquid-liquid microextraction for the determination of fungicides in wine.
abstract: A sample preparation method, dispersive liquid-liquid microextraction assisted by an emulsion with low concentration of a surfactant in water and dispersed solvent coupled with gas chromatography-mass spectrometry, was developed for the analysis of the fungicides cyprodinil, procymidone, fludioxonil, flusilazole, benalaxyl, and tebuconazole in wine. A microsyringe was used to withdraw and discharge a mixture of extraction solvent and 240 μL of an aqueous solution of Triton X-100 (the dispersed agent) four times within 10 s to form a cloudy emulsion in the syringe. This emulsion was then injected into a 5 mL wine sample spiked with all of the above fungicides. The total extraction time was approximately 0.5 min. Under optimum conditions using 1-octanol (12 μL) as extraction solvent, the linear range of the method in analysis of all six fungicides was 0.05-100 μg L(-1), and the limit of detection ranged from 0.013 to 0.155 μg L(-1). The absolute recoveries (n = 3) and relative recoveries (n = 3) were 30-83 and 81-108% for white wine at 0.5, 5, and 5 μg L(-1), and 30-92 and 81-110% for red wine, respectively. The intraday (n = 7) and interday (n = 6) relative standard deviations ranged from 4.4 to 8.8% and from 4.3 to 11.2% at 0.5 μg L(-1), respectively. The method achieved high enrichment factors. It is an alternative sample preparation technique with good performance.
authors.affiliation: Department of Chemistry, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Wan-Chi
authors.initials: WC
authors.lastname: Tseng
authors.forename: Shang-Ping
authors.initials: SP
authors.lastname: Chu
authors.forename: Po-Hsin
authors.initials: PH
authors.lastname: Kong
authors.forename: Chun-Kai
authors.initials: CK
authors.lastname: Huang
authors.forename: Jung-Hsuan
authors.initials: JH
authors.lastname: Chen
authors.forename: Pai-Shan
authors.initials: PS
authors.lastname: Chen
authors.forename: Shang-Da
authors.initials: SD
authors.lastname: Huang
mesh_terms: D004655:Emulsions; D005659:Fungicides, Industrial / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D059627:Liquid Phase Microextraction / Q000379:methods*; D012680:Sensitivity and Specificity; D012997:Solvents; D013501:Surface-Active Agents; D014867:Water; D014920:Wine / Q000032:analysis*
chemical_list: D004655:Emulsions; D005659:Fungicides, Industrial; D012997:Solvents; D013501:Surface-Active Agents; D014867:Water
keywords: dispersive liquid−liquid microextraction; fungicides; gas chromatography; improved solvent collection system; water with low concentration of surfactant; wine