Hi Jude, I didn't try it with monoterpenes but with isoprene. there, magneisum perchlorate did the job without affecting either the concentration or the d13C. hagit. -- -- Dr. Hagit P. Affek Div. of Geology and Planetary Science Caltech, MC 100-23 Pasadena, CA, 91125 phone: 626-395-2383 > I'm interested in learning the best way to scrub water out of a field > sample of plant volatized monoterpenes. The sample is being prepared > for GC/MS trace gas analysis. The concern is that the target > molecules may be in such low abundance that a conventional water > scrubber may non-specifically bind target molecules and reduce the > target signal below detection. > Are there methods that address these concerns. > Thanks in advance. > jude > > -- > ##################### > Jude Maul > Department of Horticulture > Cornell University > Ithaca, NY 14853 > 607-255-0883 (OFFICE) > [log in to unmask] > #####################