Abstract |
Dyestuffs are of major environmental interest because of their widespread use as colorants in a variety of products, such as textiles, paper, leather, gasoline and foodstuffs. Synthetic intermediates, byproducts and degradation products of these dyes could be potential health hazards owing to their toxicity and/or carcinogenicity. A liquid chromatograph was interfaced with a triple quadrupole mass spectrometer by means of a particle beam-type interface. The system was used for the analysis and characterization by electron impact mass spectra of a series of commercial dyes. The pure dyes were separated from their impurities with a reversed-phase C18 column using methanol-water as the mobile phase. Detection limits were determined using the system as a single quadrupole mass spectrometer. Sensitivity for dyes was found to be two to three orders of magnitude worse than with thermospray ionization using a wire repeller. Characterization of the azo dyes could be achieved by observing typical fragment ions formed by cleavage of the N-C and C-N bond on either side of the azo linkage and/or cleavage of the N=N double bond with transfer of two hydrogen atoms to form an amine. (Copyright (c) 1989 Elsevier Science Publishers B.V.) |