For synthetic polymer samples, matrix-assisted laser desorption/ionization (MALDI) time-of-Flight (TOF) mass spectrometry (MS) can yield qualitative information about end groups and repeat units, and also quantitative information, such as molecular masses and molecular mass distributions. Accurate quantitative measurements require equimolar responses for all sample species in the mass range over which a sample is distributed, or at least a predictable variation in response. Presently, quantitative results from MALDI are considered reliable only for narrowly distributed samples; I.e. those with a polydispersity indexf (PD, where PD = Mw/Mn) below about 1.2 [1,2]. There are instrumental and sample-related factors that can influence the relative responses of sample species, but understanding is not complete (3-7). There is not a definitive explanation for the diffculities MALDI has with more broadly distributed samples, and it has not been extablished wheter or not the currently recognized polydispersity limits can be extended by adjustments in sample preparation or by instrumental developments.
American Chemical Society; Division of Polymer Chemistry, Meeting | | | American Chemical Society (ACS)
and Guttman, C.
Response Saturation of Polystyrene in MALDI, American Chemical Society; Division of Polymer Chemistry, Meeting | | | American Chemical Society (ACS), [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=851678
(Accessed May 31, 2023)