Problems of the control of volatile halogenated hydrocarbons in tap and waste waters

The concentration of volatile halogenated hydrocarbons in chlorinated tap water does not stay constant but increases during its passage through water supply systems, which indicates a certain incompleteness and the continuation of the transformation of humic substances upon the chlorination of water. The known official (certified) procedures, including the State Standard ones, seven in number, which are based on headspace gas chromatography, do not take into account such a peculiarity of tap water and deal with the quantification of free halogenated derivatives of hydrocarbons only. The comparative evaluation of official procedures is performed, and the sources of errors exceeding the acceptable level are inventoried; methods of optimization of all analytical steps are proposed to elaborate procedures ensuring the minimal error and reliable information on the concentration of volatile halogenated hydrocarbons in tap and waste waters.