NEW INTERNATIONAL STANDARDS ACTIVITY IN POLYMER MASS SPECTROMETRY.

A new technical working area--TWA 28--in quantitative mass spectroscopy of synthetic polymers has been formed within the Versailles Project on Advanced Materials and Standards (known as VAMAS) to explore the development of a standard method for determining the molecular mass distribution of synthetic polymers (plastics).

With recent advances in mass spectrometry, it is now possible to measure the molecular mass of some biological and synthetic polymers. The distribution of the molecular chain lengths--the number of small and long ones--affects the processing of materials and the properties of the final product. The first step is to identify the mixture of chains. A variation of time-of-flight (refererred to as ToF) mass spectrometry called matrix assisted laser desorption ionization (MALDI) has the potential to be an absolute method for measuring the molecular mass of polymers. MALDI ToF mass spectrometry uses laser ablation to produce charged polymers in the vapor state, which allows the direct measurement of the mass distribution.

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 method. NIST is chairing the new working area.