Rapid colorimetric determination of ascorbic acid by solid phase extraction of iodine into a polymethacrylate matrix

The proposed iodometric solid-phase spectrophotometry method is based on interaction of ascorbic acid with molecular iodine in a solution with further extraction of the unreacted iodine into a polymethacrylate matrix followed by its spectrophotometric measurement in the solid phase. The amount of iodine extracted by the matrix is in inverse linear dependence on the concentration of ascorbic acid in the solution. The method can be employed for the range of ascorbic acid concentrations 1.0–9.0 mg dm^–3, while its detection limit is 0.8 mg dm^–3.