Multispectral Identification of Potentially Hazardous Byproducts of Ozonation and Chlorination. Part 1. Studies of Chromatographic and Spectroscopic Properties of MX

摘要

The gas chromatographic (GC) and Fourier transform infrared and mass spectroscopic (FT-IR and MS, respectively) properties of (Z)-2-chloro-3-(dichloromethyl)-4-oxobutenoic acid (MX) (a highly mutagenic byproduct of drinking water chlorination) and several related compounds were studied. Specifically, MX, the methyl ester of MX (MX-OMe), and three MX-model compounds--mucochloric acid (MCA), mucobromic acid (MBA), and 2,4-(3H,5H)-furandione (2,4 FD)--were analyzed on the GC/FT-IR and GC/MS systems. A concentration study of MX on the GC/FT-IR system revealed a minimum identifiable quantity of approximately 10 ng, with linear response over the range of 10 to 600 ng. MX was stable to approximately 260 C. The thermal decomposition product produced above that temperature was tentatively identified by GC/MS as 2-(dichloromethyl)-3-chloro-2-propenal. The GC/FT-IR detector response for 600 ng of MX was compared to that of 600 ng of MX that had been methylated. The ratio of the detector response indicated that the methylation efficiency was, at best, 40%. Additionally, several extracts of chlorinations of dissolved organic material were analyzed. No MX was detected. The approximate extraction efficiencies of MX and MCA were determined for several organic solvents, of which ethyl acetate was the most efficient for both compounds.