The certification of an absolute molecular mass distribution polymer Standard Reference Material is described. SRM 2881 is an n octyl initiated, proton terminated, narrow polydispersity, low mass, atactic polystyrene. The absolute molecular mass distribution (MMD) was obtained by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI TOF MS). A description of a new method for signal axis intensity calibration is described in detail. The certification includes estimates of uncertainties, both type A (random) and type B (systematic), for each oligomer in the sample having a concentration of at least 0.20 % of the total of all oligomers on the low mass tail of the MMD and 0.34 % on the high mass tail. Type A uncertainty was found to be the greatest contributor to the overall uncertainty of the measurement.
Pub Type: Journals
mass spectrometry, molecular mass, polydisperse, polymer, standard refernce material