CHROMATOGRAPHIC DETECTION AND CHARACTERIZATION OF HALOGENATED AQUATIC HUMIC SUBSTANCES

A study of the halogenated organics derived from the chlorination of Humic acid in the presence of bromide was undertaken. The analysis involved liquid-liquid extraction with ether of the neutral (pH 7) and acidic (pH 1) fractions of the humic solution, followed by identification of the compounds by Gas Chromatography with Electron Capture (ECD), Microwave Induced Helium Plasma (single channel (MIP) and multichannel (MMIP)) and Mass Spectroscopy (MS). Amherst drinking water was also analyzed. Parameters of pH, Cl/Br ratio, and time were investigated in humic acid chlorination (with bromide) to determine effects upon Trihalomethane (THM) formation. The effect of chloramination upon THM study vs. chlorination was also examined. GC-MS was used to identify compounds formed from Humic acid and in tap water. Selected spectra and interpretations are included. Five halogenated compounds in water were identified using GC-MS. GC-MIP and GC-MMIP were used to identify halogenated compounds by monitoring chlorine, bromine and carbon emission lines singly and simultaneously. From this empirical formulae for halogenated compounds were deduced. From all of these methods over 15 halogenated compounds have been identified from the chlorination of Humic acid and ten of these have been found to occur in finished drinking water. They are: chloroform (100 ppb), bromodichloromethane (8 ppb), dichloroacetonitrile (4 ppb), chlorodibromomethane (1 ppb) and bromoform (2 ppb). Trichloroacetic acid (100 ppb), dichloroacetic acid (10 ppb) and chlorodibromoacetic acid (1 ppb) were found in the acidic fraction. Trichloroacetaldehyde and trichloroacetone were also found but not quantitated