Polarographic and voltammetric determination of Ostacetate Blue P3R

The polarographic behaviour of anthraquinone dye Ostacetate Blue P3R in a mixed water–ethanol (1 : 9) medium was investigated, and optimal conditions were found for its determination by DC tast polarography in the 20–700 μmol l−1 concentration range, by differential pulse polarography at a dropping mercury electrode in the 1–70 μmol l−1 concentration range, as well as by differential pulse voltammetry at a hanging mercury drop electrode in the 0.2–1 μmol l−1 concentration range. The sensitivity of the determination can be further improved through adsorptive accumulation of the test substance on the surface of the hanging mercury drop electrode; five minutes accumulation in unstirred solution allows determination in the 0.02–1 μmol l−1 concentration range. Practical applicability of the newly developed methods in river water was demonstrated.