An electrospray ionization ion trap mass spectrometric (ESI-MS-MSn) study of dehydroascorbic acid hydrolysis at neutral pH

Citation
N. Cioffi et al., An electrospray ionization ion trap mass spectrometric (ESI-MS-MSn) study of dehydroascorbic acid hydrolysis at neutral pH, ANALYST, 125(12), 2000, pp. 2244-2248
Citations number
32
Categorie Soggetti
Chemistry & Analysis","Spectroscopy /Instrumentation/Analytical Sciences
Journal title
ANALYST
ISSN journal
00032654 → ACNP
Volume
125
Issue
12
Year of publication
2000
Pages
2244 - 2248
Database
ISI
SICI code
0003-2654(2000)125:12<2244:AEIITM>2.0.ZU;2-G
Abstract
The hydrolysis of dehydroascorbic acid (DAAH) at neutral pH and 27 degreesC was investigated by direct infusion electrospray ionisation ion trap mass spectrometry (ESI-MS). This approach permitted derivatisation and elution p rocedures to be avoided, reducing to the minimum extent sample manipulation and allowing a rapid and direct observation of the species involved in the reaction. Six main peaks, related to hydrated dehydroascorbate (HyDAA(-)) and diketogulonate (HyDKG(-)) anions, were observed in the mass spectra of DAAH solutions at different times of incubation and were characterised by M Sn experiments. The relevant signal intensities changed with time and a mod el, based on the irreversible pseudo-first order HyDAA(-) --> HyDKG(-) conv ersion, fitted successfully the data obtained for dehydroascorbate. The kin etic constant of the process was (3.2 +/- 0.5) x 10(-2) min(-1). The influe nce of metal ion traces on the hydrolysis rate was also checked, performing experiments in the presence of EDTA, and was found to be negligible.