Mass spectra of synthesized mixed bromochloroacetic acids

Mass spectra of methyl esters of three common drinking water chlorination by‐products, bromodichloroacetic acid, dibromochloroacetic acid and tribromoacetic acid, are presented. The spectra are obtained in electron impact and chemical ionization modes, using a quadrupole mass spectrometer. Proposed fragment ion assignments are presented in detail. Fragment clusters were identified from their m/z values and confirmed with their relative isotope ratios. The detailed mass spectra presented are especially useful because standards for these drinking water contaminants are not yet commercially available.