|MadSci Network: Chemistry|
Method for analyzing Trichloroethylene Hi Charlie: Itís not suppressing that you canít find a method for analyzing Trichloroethylene using a Hach DR 2500 spectrometer, or other such colorimetric device. Trichloroethylene is only slightly soluble in water that is only a little dissolves in water, it can remain in ground water for a long time. Trichloroethylene quickly evaporates from surface water, so it is commonly found as a vapor in the air. Trichloroethylene is a member of a group of organic compounds called volatile organic compounds. The analytical technique for analyzing for these types of compounds is called Purge and Trap Chromatographic/Mass Spectrophotometer. Volital organic compounds are transferred from the aqueous phase (water) by bubbling an inert gas, usually helium, through the water sample contained is a specially designed chamber at ambient temperature. The vapors are swept through a sorbent trap, the trap is then heated and flushed with the same inert gas to desorbe (remove) the compounds and sweep then into a gas chromatographic column that separates the compounds. The detector is a Mass Spectrometer that identifies the compounds based on their atomic mass. You can find information on the principles of operation of both the gas chromatograph and the mass spectrometer in the web. As for getting your samples analyzed, I would suggest you contact your local or state environmental agency. If this is a problem with contamination of ground water or a contaminated sight, they would know about it, and would have collected samples or have sampling ongoing. Iím sure they would be glad to show you there laboratory and how samples are collected and analyzed. Another option would be a local college or university. Iím sure they would be glad to support an inquiring young scientistís curiosity. Who knows you may end up a student there. Good Luck
Try the links in the MadSci Library for more information on Chemistry.