*** 9760224 Dwyer This Small Business Innovation Research Phase I project proposes to develop improved methods for the measurement of the molecular weight of synthetic polymers. Size Exclusion Chromatography and Matrix Assisted Laser Desorption/Ionization Mass Spectrometry(MALDI-MS) will be combined in an automated sample preparation and data analysis system. While MALDI-MS provides a direct measurement of molecular weight, accurate determinations are obtained only with narrow dispersity polymers. Chromatographic separation combined with MALDI-MS is effective for polydisperse samples.The proposed instrument utilizes established technology to concentrate/deposit chromatographically separated components onto a metal foil pre-coated with matrix. The deposit is probed by the MALDI-MS excitation laser, and spectra are collected, and processed to provide molecular weight distribution of the sample. The resolving power of MS also enables structural and comonomer composition analysis. Molecular weight measurements are predictors of polymer performance and are routinely carried out in 8,000 laboratories worldwide. Interest in determining the molecular weight distribution of commercial polymers using the MALDI-MS technique is very high. ***