One of the most significant issues in any analytical practice is optimization. Optimization and calibration are key factors in quantitation. In matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS), one of the limitations restricting quantitation is instrument optimization. Understanding of which parameters are most influential and the effects of these parameters on the mass spectrum is required for optimization. This understanding is especially important when characterizing synthetic polymers by MALDI-TOF-MS, due to the breadth of the polymer molecular mass distribution (MMD). Two considerations are important in quantitation, additivity of signal and signal to noise (S/N).In this study we consider the effects of several instrument parameters were studied using an orthogonal experimental design to understand effects on the signal-to-noise of a polystyrene distribution. The parameters examined included; laser energy, detector voltage, extraction voltage, lens voltage and delay time. Other factors considered were polymer concentration and matrix. The results showed detector voltage and delay time were the most influential of the instrument parameters for polystyrene in all trans-retinoic acid (RA) as the matrix and these parameters as well as the laser energy were most influential for the polystyrene with dithranol as the matrix.
Citation: Analytical Chemistry
Pub Type: Journals
detector voltage, extraction voltage, factorial design, laser energy, MALDI-TOP-MS, optimization, polymer mass spectrometry