Determination of Selenium (IV) by Stripping Voltammetry at a Mercury-Film Electrode

摘要

A procedure was proposed for the determination of selenium (IV) by stripping voltammetry on a mercury-film electrode at an electrolysis potential of + 0.4V versus the saturated silver-silver chloride reference electrode in a 1 M H_2SO_4 solution. The current of the cathodic peak is a linear function of the selenium (IV) concentration in the range from 5 * 10~(-3) to 3 * 10~(-1) mg/L (6.3 * 10~(-8) to 3.8 * 10~(-6)M) at a time of electrolysis of 30 s (tel). The detection limit for selenium is 1 * 10~(-4) mg/L (1.3 * 10~(-9)M) at tel = 300 s. It was shown that selenium (IV) can be determined in the presence of 10 mg/L Zn (II), 1 mg/L Cd (II), 0.5 mg/L Pb (II), and 0.2 mg/L Cu (II). A procedure for the determination of selenium in natural, mineral ,and potable water was proposed.