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

Disposable, plastic cuvettes with integrated sensor layer made of Prussian blue were used for spectrophotometric determination of vitamin C in pharmaceutical products. Ascorbates cause discolouration of the layer due to its reduction to the Prussian white. The decrease of absorbance of the film measured 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) determination of ascorbate in the 0.1–10 mM range of concentration. The test is selective for vitamin C. The results of pharmaceuticals analyses are comparable to those obtained using reference pharmacopeal method. The test enables analysis of turbid samples.