GC/MS Methodology for Priority Organics in Municipal Wastewater Treatment

摘要

A state-of-the-art review is presented on the current GC/MS methodology for the analysis of priority toxic organics in municipal wastewater treatment. The review summarizes both recent published and unpublished literature on GC/MS methods for analysis of toxic organics in municipal wastewaters and sludges. The EPA has developed methodology for the measurement of these priority toxic organics based on GC/MS technology. Succinctly, the methodology separates the purgeable priority organics from the environmental sample by purging with inert gas and trapping of the organics on a Tenax and silica gel trap. The organics are then desorbed, identified and quantitated with packed column GC/MS analysis. The methodology separates the extractable organics by extracting with methylene chloride, first at pH II and then at pH 2, and then identifies and quantitates the organics in the base/neutral and acid extracts by packed column GC/MS analysis. Municipal wastewaters and sludges contain a wide variety of extractable organics which can interfere in the GC/MS analysis. Thus, the extracts may require clean-up or organics separation before the GC/MS analyses. Principal classes of organic interferences include lipids, fatty acids and saturated hydrocarbons. The approaches to separate the desirable priority organics from the interferences include acid/base separation, molecular size separation and polarity separation.