title: Determination of volatile organic compounds in water using headspace knotted hollow fiber microextraction.
abstract: An efficient and effective headspace microextraction technique named static headspace knotted hollow fiber microextraction (HS-K-HFME) has been developed for the determination of volatile organic compounds (VOCs) in water samples. The knot-shaped hollow fiber is filled with 25μL of the extraction solvent. The excess solvent forms a large droplet (13μL) and is held in the center of the knot. Even after 20min of extraction time at high temperature (95°C) without cooling, there was still enough volume of extraction solvent for gas chromatography-mass spectrometry (GC-MS) analysis, which extends the choice of solvents for headspace LPME. Moreover, the knot-shaped fiber has a larger extraction contact interface, which increases the rate of mass transfer between the headspace and extraction solvent film attached to the fiber, thus improving the extraction efficiency. The effects of extraction solvent, temperature, stirring rate, salt concentration and extraction time on extraction performance were optimized. The calibration curves exhibited coefficients of determination (R(2)) ranging from 0.9957 to 0.9999 and the limit of detection (LOD) ranged from 0.2 to 10μgL(-1). Relative standard deviations (RSDs) ranged from 4.5% to 11.6% for intraday measurements (n=5). Interday (n=15) values were between 2.2% and 12.9%. The relative recoveries (RRs) ranged from 90.3% to 106.0% for river water and 95.9% to 103.6% for wastewater.
authors: Department and Graduate Institute of Forensic Medicine, National Taiwan University, Taipei 10002, Taiwan; Forensic and Clinical Toxicology Center, National Taiwan University College of Medicine and National Taiwan University Hospital, Taiwan. Electronic address: paishanchen@ntu.edu.tw.
authors: Pai-Shan
authors: PS
authors: Chen
authors: Department and Graduate Institute of Forensic Medicine, National Taiwan University, Taipei 10002, Taiwan.
authors: Yu-Hsiang
authors: YH
authors: Tseng
authors: Department and Graduate Institute of Forensic Medicine, National Taiwan University, Taipei 10002, Taiwan.
authors: Yuh-Lin
authors: YL
authors: Chuang
authors: Department and Graduate Institute of Forensic Medicine, National Taiwan University, Taipei 10002, Taiwan; Forensic and Clinical Toxicology Center, National Taiwan University College of Medicine and National Taiwan University Hospital, Taiwan.
authors: Jung-Hsuan
authors: JH
authors: Chen
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D057230:Limit of Detection; D059627:Liquid Phase Microextraction / Q000295:instrumentation / Q000379:methods*; D012492:Salts / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D055549:Volatile Organic Compounds / Q000032:analysis*; D014867:Water / Q000737:chemistry*
chemical_list: D012492:Salts; D012997:Solvents; D055549:Volatile Organic Compounds; D014867:Water
keywords: Gas chromatography–mass spectrometry; Headspace; Hollow fiber microextraction; River water; Volatile organic compounds; Wastewater