New MALDI matrices based on lithium salts for the analysis of hydrocarbons and wax esters

摘要: Lithium salts of organic aromatic acids (lithium benzoate, lithium salicylate, vanillate, 2,5-dimethoxybenzoate, 2,5-dihydroxyterephthalate, α-cyano-4-hydroxycinnamate and sinapate) were synthesized tested as potential matrices for the matrix-assisted laser desorption/ionization (MALDI)-mass spectrometry analysis hydrocarbons wax esters. The analytes desorbed using nitrogen (337.1 nm) ionized via attachment a cation, yielding [M + Li](+) adducts. sample preparation experimental conditions optimized each matrix stearyl behenate n-triacontane standards. performance new in terms signal intensity reproducibility, mass range occupied by ions power threshold studied compared with previously recommended 2,5-dihydroxybenzoate (LiDHB) (Cvacka Svatos, Rapid Commun. Mass Spectrom. 2003, 17, 2203). Several performed better than LiDHB. vanillate offered 2-3 times 7-9 higher esters hydrocarbons, respectively. Also, reproducibility improved substantially, making this suitable candidate imaging applications. In addition, diffuse reflectance spectra solubility compounds investigated discussed respect to compound's ability serve MALDI matrices. applicability selected was on natural samples hydrocarbons.