title: Fast automated dual-syringe based dispersive liquid-liquid microextraction coupled with gas chromatography-mass spectrometry for the determination of polycyclic aromatic hydrocarbons in environmental water samples.
abstract: An automated procedure, combining low density solvent based solvent demulsification dispersive liquid-liquid microextraction (DLLME) with gas chromatography-mass spectrometry analysis, was developed for the determination of polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. Capitalizing on a two-rail commercial autosampler, fast solvent transfer using a large volume syringe dedicated to the DLLME process, and convenient extract collection using a small volume microsyringe for better GC performance were enabled. Extraction parameters including the type and volume of extraction solvent, the type and volume of dispersive solvent and demulsification solvent, extraction and demulsification time, and the speed of solvent injection were investigated and optimized. Under the optimized conditions, the linearity ranged from 0.1 to 50 μg/L, 0.2 to 50 μg/L, and 0.5 to 50 μg/L, depending on the analytes. Limits of detection were determined to be between 0.023 and 0.058 μg/L. The method was applied to determine PAHs in environmental water samples.
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore; National University of Singapore Environmental Research Institute, T-Lab Building #02-01, 5A Engineering Drive 1, Singapore 117411, Singapore.
authors.forename: Liang
authors.initials: L
authors.lastname: Guo
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
authors.forename: Shufang
authors.initials: S
authors.lastname: Tan
authors.affiliation: Gerstel LLP, 10 Science Park Road, #02-18 The Alpha, Singapore 117684, Singapore.
authors.forename: Xiao
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore; National University of Singapore Environmental Research Institute, T-Lab Building #02-01, 5A Engineering Drive 1, Singapore 117411, Singapore. Electronic address: chmleehk@nus.edu.sg.
authors.forename: Hian Kee
authors.initials: HK
authors.lastname: Lee
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D057230:Limit of Detection; D059627:Liquid Phase Microextraction; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D012997:Solvents / Q000737:chemistry; D013594:Syringes; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D012997:Solvents; D014874:Water Pollutants, Chemical
keywords: Automated dispersive liquid–liquid microextraction; Dual-syringe autosampler; Gas chromatography–mass spectrometry; Polycyclic aromatic hydrycarbons