GEL-PERMEATION CHROMATOGRAPHY WITH INTERFERENCE REFRACTOMETRY FOR THE RAPID ASSAY OF POLYDISPERSE DEXTRANS IN BIOLOGICAL-FLUIDS

A semi-automatic system incorporating an ultra-sensitive interference refractometer coupled to a dual-column gel permeation apparatus was devised for measurement of the molecular size distribution of dextrans in small samples of serum and urine [from humans]. The system was calibrated with 17 defined dextran fractions with a range of 1200.sbd.250,000 weight average molecular weight (.hivin.Mw). Urine samples were prepared for analysis by passage through small ion-exchange columns; serum was pretreated by precipitation with trichloroacetic acid and centrifuged before the ion-exchange treatment. Internal standard (dextran, 2 .cntdot. 106 .hivin.Mw) was added to each sample before pretreatment. Data were obtained in a form suitable for computerized analysis.