A NEW PROCEDURE FOR QUANTITATIVE CORRECTION OF MATRIX-ASSISTED-LASER-DESORPTION IONIZATION TIME-OF-FLIGHT MASS-SPECTROMETRIC RESPONSE/

A simple procedure for the correction of the decreasing detection resp onse in a Matrix-assisted laser desorption/Ionization time-of-flight ( MALDI-TOF) mass spectrum with increasing ion mass is reported. On the basis of the experimental MALDI-TOF mass spectrum of a mixture of four polymethylmethacrylate (PMMA) standards (molecular masses in the rang e 4-100 kDa), present in equal molar abundance, an equation describing the MALDI-TOF response has been derived. This equation has been used to correct any subsequently recorded MALDI spectrum. As an example, th e procedure has been applied here to normalize the MALDI-TOF mass spec trum of a 1,20-di(bisphenoxy-A)eicosane based copolyformal (I) contain ing porphyrin units in the main chain. (C) 1998 John Whey & Sons, Ltd.