DETERMINATION OF GEOSMIN AND 2-METHYLISOBORNEOL IN WATER BY HEADSPACE LIQUID-PHASE MICROEXTRACTION COUPLED WITH GAS CHROMATOGRAPHY-MASS SPECTROMETRY

摘要

Geosmin (GSM) and 2-methylisoborneol (MIB) were extracted from water samples, adsorbed in organic solvent microdrop by headspace liquid-phase microextraction (HS-LPME), and were analyzed by gas chromatography-mass spectrometry (GC-MS). Influence factors such as the extraction solvent types, headspace and microdrop volumes, stirring rate, equilibrium and extraction time, and ionic strength for HS-LPME efficiency were thoroughly evaluated. Under optimized extraction and detection conditions, the calibration curves of GSM and MIB were linear in the range of 5-1000 ng/L. The detection limits of GSM and MIB were 1.1 and 1.0 ng/L, respectively. Average recoveries of 95.45-113.7% (n=5) were obtained and method precisions were also satisfactory. Trace levels of the off-flavor compounds at ng/L in tap water and raw water were successfully quantified.