Analysis of Musty Odors using SPME-GC/MS

Introduction

Japan’s tap water has a solid reputation for its safety. However, water supplies that are taken from surface water sources, such as dams, lakes and rivers, may generate musty odors during the summer. As a countermeasure, carbon treatment is being used. The substances causing the musty odor are 2-methyl- isoborneol (2-MIB) and geosmin, produced by algae and actinomyces. The odor threshold values for these substances are extremely low, in the order of several ng/L, so pretreatment is required to concentrate samples. In the Japanese goverment’s drinking water examination, the solid phase extraction GC/MS and the purge & trap GC/MS methods had been stipulated, and, in 2001, the headspace GC/MS method was added. However, the solid phase extraction GC/MS has disadvantages such as time-consuming and complex extraction procedures and large consumption of organic solvents. As for the purge & trap GC/MS method, the analysis system is expensive and maintenance is difficult. Solid phase microextraction (SPME) is a pretreatment method that extracts organic compounds from the headspace of liquid or solid samples, concentrates them, thermally desorb them in the GC injector, and introduces them into the column. This pretreatment method is attracting attention because it does not require organic solvents, is fully automated and operation is easy.

March 29, 2004 GMT