Method for characterizing the molecular weight and molecular weight distribution of ultra-high molecular weight water soluble polymers

A liquid chromatographic method for characterizing water soluble polymers by molecular weight and molecular weight distribution based on apparent size which comprises:

• (a) adding to an aqueous eluent a sample of a detectable ultra-high molecular weight polymer in a solution concentration between the detectable limit and an upper limit below the concentration at which the elution of the polymer is detrimentally influenced by concentration, the sample added being dissolved in a primarily aqueous diluent not incompatible with the eluent, the added sample volume being not greater than that volume which would detrimentally influence the chromatography;
• (b) passing the combined eluent and sample through a porous body composed of a packed bed of nonporous particles whereby the apparent size fractions of the polymer sample are separated by flow;
• (c) detecting the amount of the eluting apparent size fractions of the polymer species;
• and
• (d) using the data of step (c) to characterize the molecular weight and molecular weight distribution of the detected water soluble polymer.