Membrane-assisted solvent extraction of triazines and other semi-volatile contaminants directly coupled to large-volume injection-gas chromatography-mass spectrometric detection.
A simple device was developed for in-vial liquid-liquid extraction using a polymer membrane (nonporous polypropylene) to separate an aqueous sample from an organic extractant. The membrane consisted of tubing with an internal diameter of 6 mm and a wall thickness of 0.05 mm, which was heat-sealed at the lower end and filled with 500 microl hexane. This membrane bag was incorporated into a conventional 20 ml headspace vial suitable for a multi-purpose sampler (MPS 2, Gerstel, Mülheim, Germany) directly interfaced to a gas chromatograph with a mass-selective detector. The sampler enabled the extraction vial to be mixed at a defined temperature with subsequent large-volume injection of the organic extract taken from the membrane bag. The method was evaluated using several triazines, 2,4-dichloroaniline, alpha-hexachlorocyclohexane and phenanthrene as model compounds. Extraction parameters such as temperature, agitation speed, and extraction time were optimised. Recoveries of 60-90% were achieved after 30 min extraction. By increasing the injection volume to 100 microl, detection limits of 1-10 ng/l were determined.
Hause
Barbara
B
Department of Analytical Chemistry, UFZ Centre for Environmental Research Leipzig-Halle, Leipzig, Germany. hauser@ana.ufz.de
Popp
Peter
P
Kleine-Benne
Eike
E
D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D008567:Membranes, Artificial; D012015:Reference Standards; D015203:Reproducibility of Results; D012997:Solvents; D014227:Triazines / Q000032:analysis / Q000302:isolation & purification*; D014835:Volatilization; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification
D008567:Membranes, Artificial; D012997:Solvents; D014227:Triazines; D014874:Water Pollutants, Chemical