EFFECT OF OPERATING PARAMETERS IN PURGE-AND-TRAP GC-MS OF POLAR AND NONPOLAR ORGANIC-COMPOUNDS

The operating parameters of purge-and-trap sampling significantly affect the sensitivity of the analysis of volatile organic compounds in water samples. The effects of puge volume, sample temperature, sample volume, dry purge volume, desorption temperature, desorption time and cold-trap temperature have been studied for some polar and nonpolar organic volatiles using a purge-and-trap sampler interfaced with a direct coupling to a gas chromatograph-mass spectrometer. It is shown that the sensitivity and in some cases the specificity of the method can be greatly improved through careful optimization.