Catalytic-adsorptive stripping voltammetric measurements of ultratrace levels of tungsten.
An ultrasensitive catalytic-adsorptive stripping voltammetric procedure for trace measurements of tungsten, based on a chlorate catalytic reduction peak in a 3-methoxy-4-hydroxymandelic acid (VMA)-oxine-sulfuric acid medium is reported. Optimum experimental conditions (particularly the solution composition) are explored to give an extremely low detection limit of 5 ng/l. (2.5 x 1O(-11)M) tungsten following 5-min accumulation. The relative standard deviation (at 1 mug/l.) is 1.0%. The high sensitivity and precision are coupled to high selectivity. Simultaneous trace quantitation of tungsten and molybdenum is also illustrated.
Wang
J
J
Department of Chemistry, New Mexico State University, Las Cruces, NM 88003, U.S.A.
Lu
J
J