DETERMINATION OF PENTACHLOROPHENOL IN WATER BY MASS-SPECTROMETRIC ISOTOPE-DILUTION

A mass spectrometric isotope dilution method using 18O labeled pentachlorophenol (PCP) has been developed for determining low levels of pentachlorophenol in water. A known amount of 18O PCP is added to a measured volume of water and the combined solutions are extracted. The methyl ether derivative is prepared by reacting the extract with excess ethereal diazomethane solution and the fraction of 18O PCP is determined from the ion intensities in the mass range m/e 278 to 290 in the GC/MS analysis. The lower useful limit is approximately 0.2 x 10-6 g with a relative standard deviation of approximately 8%. © 1979, American Chemical Society. All rights reserved.