Determination of α- and β-lactose in dairy products by totaly aqueous liquid chromatrography

Abstract In the proposed method, the mobile phase is pure water and sample preparation requires only dilution and centrifugation steps. A total determination requires 15 min including sample handling. Total and anomeric ratios of lactose were determined in samples of yoghurt, milk, dry milk, and ice cream. The method variability was evaluated by using five mild samples, randomly selected from the same dairy; for each sample, 3–5 replicate chromatograms were obtained. The mean total lactose in these mild samples was 4.50% with a pooled standard deviation of 0.132%.