THE ANALYSIS OF MACROMOLECULES UNDER AQUEOUS AND NON-AQUEOUS CONDITIONS DETERMINING THE PARTICLE SIZE DISTRIBUTION AND MOLECULAR WEIGHT DISTRIBUTION USING LOW AND RIGHT ANGLE LASER LIGHT SCATTERING AND PHOTON CORRELATION SPECTROSCOPY (PCS) DETECTION WITH SIZE EXCLUSION CHROMATOGRAPHY. Trevor Havard and Peter Wallace.Precision Detectors Inc., 160 Old Farm Road, Amherst, MA 01002 Tel 413 256 0516.

The objective of this paper is the separation and analysis of the particle size and molecular weight of macromolecules like Poly-Carbohydrates and Proteins, carried out under aqueous conditions, and macromolecules like polystyrene, star branched polystyrene and dendrimers. The paper will describe a new instrument that enables the molecular weight and particle size distribution to be obtained simultaneously. The paper will also describe how an instrument of this type can be used for the first time in flow mode to determine the molecular weight distribution as well as the hydrodynamic radius of the macromolecule eluting from an SEC system. This system is especially useful in determining the amount of aggregation that occurs while trying to dissolve certain macromolecular systems like carbohydrates and proteins into solution under different conditions where pH, temperature may be varied. The results show the effective use of Photon Correlation Spectroscopy (PCS) to determine aggregation, branching, and size, independent of the usual chromatographic integration and baseline user selection. The use of Photon Correlation Spectroscopy as a technique for characterizing particles is well documented. However, until now there has never been an attempt to make these important measurements in a flowing SEC system.