Author(s): Yoshitomo IKAI, Sachiyasu HONDA, Naoki YAMADA, Shouko ONUMA, Banichi TOMITA
A sensitive and reliable method for the analysis of geosmin and 2-methylisoborneol (2-MIB) in water sample was developed. In this study, geosmin and 2-MIB in the sample were enriched 40-fold using a technique of solid phase extraction and the resulting enriched solution was subjected to automated headspace-GC/MS system to determine them. The separation of the compounds was performed on a DB-1 capillary column and the detection was carried out by EIMS operated in either full-scan or selected ion monitoring (SIM) mode. In the SIM mode, the two compounds were determinable at the concentration of 0.1 ppt, and the recoveries and coefficients of variations were 104 and 6.1% for geosmin, and 115 and 7.5% for 2-MIB, respectively, at the addition level of 1 ppt. Although the detection limits in full-scan mode were 10-fold worse than those of SIM, it allows both determination and mass spectroscopic identification of the two compounds at the level of 1 ppt.