Determination of selenium in municipal-waste incineration fly-ash by microwave digestion graphite-furnace AAS with a Zeeman-effect background correction

Municipal-waste incineration fly-ash samples were digested by microwave-digestion procedures with an acid mixture of HClO4-HNO3-HF. Then, selenium in the digested sample solution (in 1 M-HCl, trace-HClO4) was directly determined using graphite-furnace AAS with a Zeeman-effect background correction. Platform atomization was used and peak-area absorbance measurements were utilized. Palladium and nickel were used as modifiers. The palladium modifier stabilized selenium at a higher temperature than did the nickel modifier, resulting in a better sensitivity. An aqueous calibration curve was used and the method of additions was not necessary. The present investigated method was applied to the analysis of a certified reference material (BCR No. 176). The analytic result was in good agreement with the certified value. The present method has been successfully applied to the analysis of actual samples.