Identification of the hydrolysis products of AlCl₃·6H₂O by electrospray ionization mass spectrometry

Abstract

The hydrolysis reactions of AlCl3 in 0.1 M aqueous solutions at pH 3.27-4.20 were monitored by electrospray ionization time-of-flight mass spectrometry (ESI-ToF MS) as a function of time. The cationic and anionic ESI mass spectra of aluminum(III) solutions gave strong evidence of the presence of a variety of monomeric and polymeric complexes. Competition between the OH- and Cl- ligands within the same aluminum core was observed. The influence of the sample cone voltage on the product distribution was also explored. The optimum sample cone voltage for the cationic spectra was 70 V. For the anionic spectra no optimum sample cone voltage was found and the appearance of the anionic spectra was strongly dependent on the sample cone voltage within the whole range explored.

Role of Aluminum Speciation in the Removal of Disinfection Byproduct Precursors by a Coagulation Process

“…This is consistent with the results of Rämö et al (21). As shown in Figure 3b According to a previous study (22), the presence of TMA adducts also was observed in the samples due to pH adjustment by TMA. In this study, another very intense signal at m/z 113 was observed as well; this may be assigned to [K2Cl] + .…”

Aluminum speciation of coagulants with low concentration: Analysis by electrospray ionization mass spectrometry

“…Therefore, too low or high sample cone voltage was not suitable for detecting all aluminum species. This is consistent with the previous literature that low or high sample cone voltage could not benefit aluminum species analysis at a high aluminum concentration [14]. Other studies also indicated that sample cone voltage responsible for ion extraction from the ionization source into the mass analyzer affected ESI-MS analysis result [27][28][29].…”

Identification and fragmentation of hydrolyzed aluminum species by electrospray ionization tandem mass spectrometry

“…In a previous MS study, 1 we showed that the mix of species in aqueous aluminum chloride solutions is more complex than suggested by models obtained by potentiometric methods. 2 -6 Cationic and anionic electrospray ionisation (ESI) mass spectra of aluminum(III) solutions provided strong evidence for the presence of a variety of monomeric and polymeric complexes, from Al 1 to Al 32 core complexes, with different amounts of water molecules.…”