Hollow Fiber-Protected Liquid-Phase Microextraction of Triazine Herbicides

• Published in: Analytical chemistry (Washington) Vol. 74; no. 3; pp. 648 - 654
• Main Authors: Shen, Gang, Lee, Hian Kee
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.02.2002
• Subjects: Analysis; Analytical chemistry; Applied sciences; Chemistry; Chromatographic methods and physical methods associated with chromatography; Exact sciences and technology; Gas Chromatography-Mass Spectrometry; Global environmental pollution; Herbicides; Herbicides - analysis; Humic Substances - pharmacology; Hydrogen-Ion Concentration; Microchemistry - instrumentation; Microchemistry - methods; Other chromatographic methods; Pollution; Toluene; Triazines; Polymeric membrane; Chemical analysis; Porous membrane; Propylene polymer; Pesticides; Liquid phase; Solvent extraction; Herbicide; Gas chromatography; Pollution; Sample preparation; Hollow fiber; Triazine derivatives; Environment; Performance; Mass spectrometry
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac010561o

A new microextraction technique termed hollow fiber-protected liquid-phase microextraction (LPME) was developed. Triazines were employed as model compounds to assess the extraction procedure and were determined by gas chromatography/mass spectrometry. Toluene functioned as both the extraction solvent and the impregnation solvent. Some important extraction parameters, such as effect of salt, agitation, pH, and exposure time were optimized. The new method provided good average enrichment factors of >150 for eight analytes, good repeatability (RSDs <3.50%, n = 7), and good linearity (r 2 ≥ 0.9995) for spiked deionized water samples. The limits of detection (LODs) were in the range of 0.007−0.063 μg/L (S/N = 3) under selected ion monitoring mode. In addition to enrichment, hollow fiber-protected LPME also served as a technique for sample cleanup because of the selectivity of the membrane, which prevented large molecules and extraneous materials, such as humic acids in solution, from being extracted. The utilization of this procedure in the extraction of a slurry sample (mixture of soil and water) also gave good precision (RSDs <5.00%, n = 3) and LODs (0.04−0.18 μg/L, S/N = 3). Finally, the comparison of the new method with the static solvent drop LPME and solid-phase microextraction was performed. The results demonstrated that hollow fiber-protected LPME was a fast, accurate, and stable sample pretreatment method that gave very good enrichment factors for the extraction of triazine herbicides from aqueous or slurry samples.