Voltammetric determination of sodium anthra-quinone-2-sulfonate (AQ) was investigated at a polished silver solid amalgam electrode (p-AgSAE) and at a mercury meniscus modified silver solid amalgam electrode (m-AgSAE) (inner diameter of both 0.5 mm). The reaction mechanisms of AQ at p-AgSAE and at m-AgSAE were studied by cyclic voltammetry, direct current voltammetry, and by elimination voltammetry with linear scan.
Limits of detection obtained by differential pulse voltammetry were 1 9 10(-6) mol dm(-3) for p-AgSAE and 4 9 10(-7) mol dm(-3) for m-AgSAE. Both electrodes were successfully applied for differential pulse voltammetry of AQ in model samples of deionized water, river water, and human urine.