Disposable integrated cuvette test for quantitative determination of vitamin C in pharmaceutical products

Disposable, plastic cuvettes with integrated sensor layer made of Prussian blue were used for spectrophotometric determination of vitamin C in pharmac eutical products. Ascorbates cause discolouration of the layer due to its r eduction to the Prussian white. The decrease of absorbance of the film meas ured at 720 nm is used as the analytical signal. No additional reagents are required. Under optimized conditions the test allows fast (up to 5 min) de termination of ascorbate in the 0.1-10 mM range of concentration. The test is selective for vitamin C. The results of pharmaceuticals analyses are com parable to those obtained using reference pharmacopeal method. The test ena bles analysis of turbid samples. (C) 1999 Elsevier Science B.V. All rights reserved.