The recertification of the polystyrene standard reference material, SRM 706a, is described. The Mw of SRM 706a by light scattering was determined to be 2.85 x 105 g/mol with a sample standard deviation of 0.019 x 105 g/mol. A combined expanded uncertainty of 0.17 x 105 g/mol is estimated for this determination. The Mw obtained for on SRM 706 recently run. The Mw obtained for SRM 706a is also in excellent agreement with the Mw obtained by ultracentrifugation in 1967 of 2.88 x 105 g/mol on SRM 706. No bottle-to-bottle variability was found for SRM 706a in a size exclusion chromatography study.
Citation: NIST Interagency/Internal Report (NISTIR) - 6091
NIST Pub Series: NIST Interagency/Internal Report (NISTIR)
Pub Type: NIST Pubs
average molecular weight, molecular weight standard, polystyrene standard, SRM 706, SRM 706a, Standard Reference Material, weight