REDUCTION IN SAMPLE FOAMING IN PURGE AND TRAP GAS CHROMATOGRAPHY-MASS SPECTROMETRY ANALYSES

In the determination of volatile organic compounds in industrial effluent waters and process streams by purge and trap GC/MS, foaming of the sample has been a serious problem. The foam tends to enter the transfer line leading to the sorbent trap and may actually reach the trap itself. This has several negative effects on the current and subsequent determinations, including deactivation of the trap and introduction of thermal decomposition products from labile, nonvolatile materials. Two methods to reduce foaming are evaluated, one employing a silicone surfactant and a second involving heat dispersion of the foam. The qualitative and quantitative aspects of these two foam-reduction methods are described for volatile priority pollutants in spiked pure water and soap solutions. © 1979, American Chemical Society. All rights reserved.