A gel-permeation-chromatography (GPC) procedure using Sepharose CL 4B (9012-36-6) and Cadoxen (14874-24-9) to give a high-resolution separation of cellulose (9004-34-6) is described. The GPC technique was used to compare the long-term stability of naturally aged cotton textile fibers washed in distilled-deionized water, tap water, calcium bicarbonate (20 ppm), or calcium sulfate (20 ppm). The results, which were verified by viscometry, showed that tap water or calcium sulfate-washed fibers exhibited less degradation after accelerated thermal aging (70 degrees, 50% relative humidity, 70 days) than the untreated control. The distilled-deionized water or calcium bicarbonate-washed fibers showed greatly increased deterioration relative to the control.