Study of the mass spectrometric behaviour of phthalocyanine and azo dyes using electrospray ionisation and matrix‐assisted laser desorption/ionisation

Abstract

The negative ion MALDI-MS and ESI-MS behaviour of sulphonated copper phthalocyanine dyes has shown the presence of both anionic and radical anionic species. Substituent groups such as sulphonates and linker arms, as are present in commercial dyes such as Remazol TB and Everzol TB, are found to be labile and the dyes undergo in-source fragmentation in both MALDI-MS and ESI-MS. Ions corresponding to sodium salts can be formed. It appears that Cu is firmly bound in the phthalocyanine structure, unlike the corresponding Mg and Al chelates that can undergo demetallation. The application of ESI-MS n confirmed that these labile groups can be fragmented from the dye molecules and, in addition, SO 2 losses are observed as for EI-MS. Hydrolysed commercial azo dyes such as Remazol Black B (I) and Remazol Red RB (III) showed both singly and doubly charged molecular anion species as well as sodium salts using negative ion ESI-MS, but did not desulphonate like the copper phthalocyanine dyes. The application of ESI-MS n revealed fragmentation of the dye molecules with the loss of entities such as HOCH 2 CH 2 SO 2 C 6 H 4 N 2 (for both dyes) and SO 2 (for Remazol Black B). MALDI-MS, ESI-MS and ESI-MS n can therefore be used for the characterisation of such dyes by exploiting these fragmentation processes, and some structural information can be obtained for the dyes whose structures are not in the public domain.

Characterisation of selected drugs with nitrogen-containing saturated ring structures by use of electrospray ionisation with ion-trap mass spectrometry

“…This table contains similar data from recent publications (and unpublished work) for other low-molecular-mass molecules by the research group at the University of Ulster [1,9,10,[15][16][17][18][19][20] using the same LCQ and identical experimental conditions.…”

The Phthalocyanine Prototype Derivative Alcian Blue Is the First Synthetic Agent with Selective Anti-Human Immunodeficiency Virus Activity Due to Its gp120 Glycan-Binding Potential

“…As show in Fig. 2 29 and 1026.24 may correspond to two or three losses of the dimethylamino groups of the tetramethylisothiouronium side chains, since a certain degree of in-source fragmentation has been described for other phthalocyanines (11). Both fractions 42 and 44 were shown to be inhibitory against HIV-1(III B ) in CEM cell cultures.…”

“…No molecular ion peak was detected, and only very-low-intensity peaks whose putative origins will be discussed later were observed at higher m/z values (1,026 and 1,068). Both fractions were further analyzed by MALDI, because this technique has been successfully employed for the characterization of the molecular mass of phthalocyanines (11). As show in Fig.…”

A critical evaluation of high performance liquid chromatography‐electrospray ionisation‐mass spectrometry and capillary electrophoresis‐ electrospray‐mass spectrometry for the detection and determination of small molecules of significance in clinical and forensic science

“…The negative-ion MALDI-MS and ESI-MS behaviour of sulphonated copper phthalocyanine dyes has shown the presence of both anionic and radical anionic species [133]. Substituent groups such as sulphonates and linker arms, as are present in commercial dyes such as Remazol TB and Everzol TB, were found to be labile and the dyes underwent in-source fragmentation in both MALDI-MS and ESI-MS. MS n characterisation of a one-linker arm species at m/z 1077.0 ( Fig.…”