Determination of 2-Methylisoborneol and Geosmin in Water Using Portable Gas Chromatography-Tandem Mass Spectrometry Coupled with Solid Phase Micro-extraction in Field

A solid phase micro-extraction coupled with portable gas chromatography-tandem mass spectrometry method for field analysis was developed for the determination of 2-methylisoborneol(2-MIB) and geosmin (GSM) in water. The selective reaction monitoring(SRM) parameters were optimized. The SPME conditions such as stirring rate, extraction time and extraction temperature were investigated. Optimum SPME conditions were as follows: stirring rate of 1200 r/min, extraction time of 40 min, extraction temperature of 70 degrees C. Limits of detection of 2-MIB and GSM were 1.1 ng/L and 0.5 ng/L respectively. Limits of quantification were 3.6 ng/L and 1.8 ng/L respectively. Linear detection range was 5-100 ng/L with correlation coefficients of 0.9922 and 0.9996, respectively. At the spiked level of 10-100 ng/L, the average recoveries of target compounds were 91.5% - 107.9% with RSDs <= 10.1% (n = 6). This method combines simplicity and rapidtity of SPME and high sensitivity and high selectivity of tandem mass spectrometry, and performance of the method is comparable to that of national standard method. It is especially suitable for the field determination of 2-MIB and geosmin GSM in real water samples.