Authors: M Careri L Elviri A Lorenzi A Mangia A Penna G Predieri
Publish Date: 2011/08/05
Volume: 60, Issue: 3, Pages: 359-365
Abstract
In this work sol–gel derived silica films were prepared for direct desorption/ionization of organic compounds in MALDITOF–MS analysis with the aim of improving method precision and of reducing interfering signals at low m/z values Two commonly used MALDI matrices 25dihydroxybenzoic acid DHB and αcyano4hydroxycinnamic acid CHCA were incorporated into the sol–gel network in order to absorb laser energy and to induce analyte desorption/ionization with low or absent background signals in the mass spectra To achieve a reproducible xerogel film formation experimental parameters for its deposition were optimized The gel matrices were characterized by Fourier Transform Infrared FTIR spectroscopy Xray Diffraction XRD and Scanning Electron Microscopy SEM analysis The results proved the embedding of the matrix molecules in a disperse form into the homogeneous sol–gel material The sol–gel matrix was then tested for the qualitative and quantitative analysis of two reference peptides such as Bradykinin and P14R In addition spectral quality and method performance were assessed for quantitation of melamine a lowmolecular weight compound of food safety concern In all cases high quality spectra and excellent mass accuracy between 35 and 13 ppm were observed Furthermore the experimental results evidenced a significant improvement of the measurement repeatability on spot and between spots relative standard deviation 10 with respect to the traditional drieddroplet sample deposition method Good sensitivity and linearity in the concentration range explored were obtained for peptides and melamine demonstrating the suitability of the sol–gelbased matrix to be used for quantitative analysisThe Project was funded by Laboratorio Regionale SITEIA PRRIITT Misura 4 “Sviluppo di rete” Azione A—Laboratori di ricerca e trasferimento tecnologico DGR n 1853/07 The facilities of the Centro Interdipartimentale Misure CIM “Giuseppe Casnati” University of Parma were used to perform MALDITOF–MS analysis Thanks are due to Dr Marco Rocchetti for helpful discussions and suggestions
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