SBIR-STTR Award

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.

This Small Business Innovation Research (SBIR) Phase II project is to continue development and commercialization of instrumentation to improve the accuracy of the determination of the molecular weight of polydispersive synthetic polymers by the automated combination of Size Exclusion Chromatography (SEC) and Matrix Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI-MS). Combining both techniques eliminates errors due to sample polydispersity, SEC standards incompatibility and complexity in sample structure. The SEC eluent is "painted" onto a foil, precoated with MALDI-MS matrix, to produce a track which is automatically probed by the MALDI-MS laser. The spectra are summed and the composite used to calculate molecular weight moments. Research will quantify the effects of mass discrimination, matrix/analyte ratio, polymer solubility and MALDI-MS instrumental bias. Prototype interface hardware will be simplified for ease of operation and cost reduced for wider appeal. The project is supported by two manufacturers of polymer instrumentation and two polymer manufacturers. Some 8000 laboratories world-wide routinely use SEC for molecular weight determination to control and predict polymer performance. MALDI-MS is the fastest growing instrumental technique for large molecule analysis.