Mass spectra of chlorinated aromatics formed in pulp bleaching 2—Chlorinated guaiacols

The fragmentation of chlorinated guaiacols (2-methoxyphenols) on electron impact has been studied. The most common fragmentation processes are interpreted and in some cases the small differences between spectra of positional isomers are explained. In addition to the well-known alkyl-oxygen fission (loss of methyl radical), metastable ion studies and deuterium labelling have indicated several new fragmentation pathways. The most characteristic are the formation of M? CH₃? HCl]⁺ and M? CH₃? Cl]^+· ions. In general, however, the spectra of positional isomers are shown to be very similar.