DIRECT MONITORING OF LASER-ABSORPTION OF MALDI MATRICES BY FAST PIEZOELECTRIC TRANSDUCER

The absorption of laser energy by recently found matrices used in matr ix assisted laser desorption ionization (MALDI) detection of large DNA segments: 3-hydroxypicolinic acid (3-HPA), picolinic acid (PA), compo site matrix (PA + 3-HPA) and 3-aminopicolinic acid (3-APA), was studie d by using a fast piezoelectric transducer for solid matrices and for their aqueous solutions. A nonlinear dependence of acoustical signal o n laser fluence was found for PA, PA + 3-HPA and 3-APA matrices at 266 nm. Near linear dependence was found for 3-HPA at 266 nm. There was n o strong deviation from linear power dependence for any of these matri ces at 355 nm. Possible mechanisms to account for the observed nonline arity are discussed.