INVESTIGADORES
BUTLER Matias
congresos y reuniones científicas
Título:
Calcium complexation applied to the analysis of resorcinol and analogs in mixtures using HPLC-ESI-MS
Autor/es:
BUTLER M.; ARROYO MAÑEZ P.; CABRERA G. M.
Lugar:
Campinas
Reunión:
Conferencia; V BRMASS Conference; 2013
Institución organizadora:
Sociedade Brasileira da Espectrometria de Massas
Resumen:
Complexation
with metal ions in solution, followed by efficient transport of the charged
complexes to the gas phase by electrospray ionization (ESI), represents a
promising method for ionization of a variety of analytes, especially for those
that are not directly amenable to ESI. The use of metal ions may produce very
stable metal coordination complexes, and therefore alkaline earth and
transition metal ions have been used in ESI for many types of compounds, allowing
the differentiation of isomers by mass spectrometry [1]. Most of the
published articles dealing with metal complexation and ESI-MS analysis of
compounds with phenolic functionalities are referred almost exclusively to
natural products of the polyphenol family.
Resorcinol
(1,3-dihydroxybenzene) is a common structural feature of agrochemicals,
pharmaceutical drugs and their metabolites, as well as an environmental
pollutant. Furthermore, their derivatives are of widespread occurrence among
natural products, such as resveratrol and alkylresorcinols.
Mass
spectrometric analyses were performed using a Bruker micrOTOF-Q II mass
spectrometer equipped with ESI and Agilent 1200 Series LC was used for HPLC
studies. Resorcinol and its isomer, catechol, were not detected in the positive
ion mode mass spectra. Adding the metal solution postcolumn at the interface
between the LC column and the source provided an easy way to obtain the mass spectra
with significant structural information. Thus, singly/doubly charged adducts
formed from neutral or deprotonated ligands as well as the protonated molecules,
were produced in the gas phase using calcium. Quantum chemical calculations
were carried out at the B3LYP/6-311+G(d,p) level, proposing structures for some
of the observed species and providing a
better understanding of their formation.
Mango
peel is known to contain 5-alk(en)ylresorcinols, which have been characterized
by HPLC-APCI-MS [2]. Calcium complexation was essayed on mango peel extracts,
observing peaks related to the protonated molecule of the alk(en)ylresorcinols
as well as doubly charged calcium complexes. Therefore, useful structural information
could be obtained from the observed ionic species.