STRUCTURAL CHARACTERIZATION OF REACTIVE DYES USING LIQUID SECONDARY-ION MASS-SPECTROMETRY TANDEM MASS-SPECTROMETRY

Reactive Blue 19 (RB 19), its reactive form (RB 19-VS) and its hydroly zed form (RB 19-OH) were examined using liquid secondary ion mass spec trometry/tandem mass spectrometry (LSIMS/MS/MS) in the negative-ion mo de under low-energy collision conditions (240-300 eV). Structurally ch aracteristic fragment ions were obtained, none of which has been previ ously reported for these reactive dyes. Among the ions obtained were S O3- ions, ions due to central amino cleavage and reactive group cleava ge, and ions due to loss of SO3 and SO2. Possible pathways for the for mation of product ions are proposed. The structural information obtain ed should help to characterize and identify reactive dyes better.