The polydispersity in the degree of functionalization for two calixresorcinarenes was determined by measuring their molecular mass distribution with matrix-assisted laser desorption/ionization time of flight mass spectrometry. A mathematical method for polydisperse materials is described that creates a calibration curve to correct the ion intensities in the mass spectrum to give a more reliable molecular mass distribution. Correction is required due to various sample preparation and instrumental effects that may produce a systematic bias on the number of oligomers measured. This method employs gravimetric mixtures of analytes with different degrees of functionalization. One calixresorcinarene was found to give accurate molecular mass distributions with little correction, while another having a very similar molecular structure was found to exhibit strong over counting of oligomers with a high degree of functionalization.
Citation: Rapid Communications in Mass Spectrometry
Pub Type: Journals
glass, mass spectrometry, photolithography