CIOP   05384
CENTRO DE INVESTIGACIONES OPTICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Photoacoustic and luminescence characterization of heterocyclic aromatic basic UV-MALDI matrices
Autor/es:
PETROSELLI GABRIELA; DAVID GARA PEDRO; BILMES GABRIEL; ERRA BALSELLS ROSA
Lugar:
Mendoza
Reunión:
Congreso; 21st Inter American Photochemical Society (I-APS) Conference; 2011
Resumen:
Ultraviolet Matrix-assisted laser desorption/ionization (UV-MALDI) is a method based on dispersing a macromolecule (analyte) in a large excess of a matrix (photosensitizer), both in solid sate. The solid mixture is irradiated with a laser pulse and vaporizes. Analyte gas ions are formed and then detected by mass spectrometry (MS). The mechanism of ionization during MALDI is still poorly understood and no adequate quantitative model for the complete process exists. The UV-MALDI technique involves both laser ablation and ionization of the matrix/analyte mixture after electronic excitation of the matrix. The knowledge of the thermal deactivation process of common UV-MALDI matrices should play a critical role in understanding why some matrices lead more abundant post-source decay as well as prompt decay of the analyte. Furthermore, it will be helpful in order to choose the proper matrix to optimize UV-MALDI-MS analysis. In this work we studied a group of recently proposed matrices used in UV-MALDI-MS for lipids analysis. The photophysical, photochemical and spectroscopic behaviour of: 9-aminoacridine (9AA), 3-aminoquinoline (3AQ), 2-(2-aminoethylamino)-5-nitropyridine (AAN) and 3,4-dihydro-7-methoxy-1-methyl-9H-pyrido[3,4b]indole (harmaline, Hla) were characterized in acetonitrile solutions. We studied the photostability of those molecules; their absorption and emission properties in steady-state conditions and the calorimetric behaviour and triplet state properties by using photoacoustics measurements.