Ultra trace Determination of Water Odorants in Amir Kabir Dam by Modified Solid Phase Microextraction and Gas Chromatography-Mass Spectrometry

In the present work a modified in-tube solid phase microextraction technique followed by gas chromatography-mass spectrometry (GC-MS) has been applied for determination of water odorants. Geosmin, 2-methyl isoborneol, 2-isopropyl-3-methoxy pyrazine, 2-isobutyl-3-methoxy pyrazine and 2,4,6-trichloroanisol are of the most important odorants which have been studied. In the described method, analytes were extracted from the headspace of the sample into the sorbent phase coated on the inner surface of capillary tubes and were desorbed by small portions of organic solvent. After injection of 2 micro liter of the sample, the separated analytes were determined on the basis of the most intensive specific ion in the mass spectra. The most important parameters affecting the quality of the analysis were examined and compared to other methods. Reproducibility (3.6 – 9.5%), linear calibration range (5 – 1000 ngL-1) and sensitivity of the method (LODs = 0.9 – 2.4 ngL-1) were satisfactory for application in environmental analysis.