Patent ID: 6868715

Claim:
A method for the determination of polymer molecular weight, comprising: injecting a known volume of an analytical sample comprising a polymer reaction product of a diphenyl carbonate and a dihydric phenol into a flow analysis system comprising an on line flow path through (1) a chromatographic column, (2) a sequential concentration detector, and ( 3 ) a sequential waste reservoir, and an off-line split flow path from the cocentration detector to a molar mass detector then to the waste reservior; effecting a minimally dispersive separation of the analytical sample with the chromatographic column to yield a first high molecular weight fraction in solvent; determining a polymer concentration in the high molecular weight fraction in solvent using the concentration detector; separating the high molecular weight fraction in solvent into a diverted high molecular weight fraction and a portion comprising solvent; discharging the solvent portion directly and without further processing to the waste reservoir; determining off-line the molar mass using the split flow path molar mass detector on the diverted high molecular weight fraction; and deriving an average molecular weight from the polymer concentration and the molar mass.