DETERMINATION OF POLAR VOLATILE ORGANIC-COMPOUNDS IN WATER BY MEMBRANE PERMEATE AND TRAP GC-MS

A novel approach is presented combining semipermeable membranes with the accepted purge and trap gas chromatography-mass spectrometry (GC-MS) technology to produce a method of selectively extracting polar, volatile organic compounds from water, particularly those compounds not amenable to purge and trap GC. The flat-sheet, semipermeable membrane is positioned between the two Plexiglas plates of a dialyzer. In the groove of one plate, the water sample is pumped over the membrane. In the groove of the second plate, helium sweeps the permeated compounds onto the top of a trap (Tenax, Tekmar; Cincinnati, OH). After suitable permeation time, the analytes are desorbed from the trap into a capillary column GC-MS system. Preliminary experiments show the ability to detect analytes such as 2-propanol, 2-methyl-1-propanol, and 1, 4-dioxane at concentrations `100 µg/L. The reproducibility, as well as the effects of temperature, sample flow rate, and helium flow rate, are discussed. © Oxford University Press 1993.