Determination of mercury in air by atomic absorption spectrometry after collection on potassium permanganate-coated glass beads.

Abstract

For collection of mercury in air, use of KMnO4-coated glass beads was proposed. A 500 ml of glass bead (1432 mesh) was immersed in HF(5%)/KF(20 %) solution for 2 h, washed with water, placed in an eggplant-shape flask containing 200 ml of water and 10 g of KMnO4, and then dried at 80°C under reduced pressure while occationally shaking. The surface of glass beads was thus coated with KMnO4, amount of which was estimated to be 6 mg per 1 g of glass beads. Air sample, usually 150 l, was passed at a flow rate. 5 l/min through a glass column (80 mm×11 mm i.d.) packed with 3 g of the KMnO4-coated glass beads. Then, a reductant solution consisting of H2SO4(1 M) SnCl2 (5%)-NH2OH · HCl(5%) was fed to the column and mercury adsorbed was eluted for successive determination by atomic absorption spectrometry. Although interference due to sulfur dioxide was serious, it could be eliminated by passing the air sample to 0.1 M basic H2O2(0.3%). The concentration of mercury in the air varied between (421)ng/m3.