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 response 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 range 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, the procedure has been applied here to normalize the MALDI-TOF mass spectrum of a 1,20-di(bisphenoxy-A)eicosane based copolyformal (I) containing porphyrin units in the main chain.