An automated headspace SPME-GC-ITMS technique for taste and odour compound identification

Abstract

A simple, automated and efficient method is presented for routine analysis of taste and odour compounds in water samples. The following compounds were investigated: hexanal, heptanal, 2t,4t-heptadienal, 2t,4t-octadienal, 2t,6t-nonadienal, 2t,6c-nonadienal, 2-methylisoborneol (MIB), 2t,4t-nonadienal, β-cyclocitral, 2t,4t-decadienal, geosmin and β-ionone. Headspace solid-phase microextraction (SPME) coupled with gas chromatography (GC and low-resolution ion-trap mass spectrometry (ITMS) was used for quantification of these compounds. A 65-μm polydimethylsiloxane/divinylbenzene (PDMS/DVB) fibre was used for headspace SPME analysis. Method detection limits for all compounds analyzed are at the ng/L level and are lower in most cases than sensory analysis can detect. The method was employed for the analysis of lake and reservoir water samples from several coastal British Columbia drinking water sources during the summer of 2001. Geosmin was the only compound detected and was found at concentrations up to 26 ng/L. To our knowledge the method presented is unique in terms of full automation and represents a sensitive and efficient tool for studying and monitoring taste and odour compounds in water sources. © 2004 CAWQ.