INTERNATIONAL STANDARDS ACTIVITY IN POLYMER MASS SPECTROMETRY.

NIST will lead a new technical working area in quantitative mass spectroscopy of synthetic polymers recently formed under the auspices of VAMAS, the Versailles Project on Advanced Materials and Standards. The objective is to develop mass spectrometry as a quantitative, standard method to determine the molecular mass distribution of synthetic polymers. With recent advances in mass spectrometry it is possible to measure the molecular mass of some biological and synthetic polymers. Among the advances is a variation of time-of-flight mass spectrometry, MALDI ToF MS, in which laser ablation is used to produce charged polymers in the vapor state. This technique has the potential to be an absolute method for measuring the molecular mass distribution (MMD) of synthetic polymers, a long sought after goal in polymer characterization owing to its impact on polymer processing and macroscopic properties. Comparisons of mass distributions measured by MALDI ToF MS with moments of the mass distribution determined by existing methods reveal discrepancies that must be resolve if the mass spectrometry is to be accepted as a standard method. The VAMAS activity brings together leading laboratories in Japan, Germany, Italy, Canada, and the United States in a collaborative research project that will develop the test protocols and establish the systematic measurement uncertainties of the MALDI ToF MS method. A standard method for determination of the mass distribution of synthetic polymers is an anticipated output.