Determination of Trace Anions in Sodium Carboxymethyl Cellulose by Ion Chromatography

An ion chromatography (IC) method coupled with solid-phase extraction was established for the simultaneous determination of trace organic acids and inorganic anions in sodium carboxymethyl cellulose (CMC). To prevent CMC from contaminating analytical column, a self-packed solid-phase extraction column packed with quaternized adsorbents was applied in sample pretreatment. An IonPac, AS11-HC column was used as the analytical column for separation of glycolate, chloroacetate, chloride, and sulfate with gradient elution of potassium hydroxide at a flow rate of 1.0 mL min −1 . Under the optimized chromatographic conditions, the linearity of the method was satisfactory over a concentration range of 0.5–150.0 mg L −1 with correlation coefficients of 0.9992–0.9999, and the limits of detection varied from 0.05 to 0.1 mg L −1 , based on the signal-to-noise ratio of 3. The proposed method was successfully applied to the analysis of organic acids and inorganic anions in CMC samples. The recoveries ranged from 86.7 to 109.0% with the relative standard deviations (RSDs) over the range of 0.32–3.61%. The method offers a reliable application for the analysis of trace organic acids and inorganic anions in complex anionic cellulose.