1998 Volume 47 Issue 3 Pages 149-155
It has been found that spectral interferences based on the molecular absorbance occurs at 196.0 nm of the selenium absorption line when a selenium sample solution containing 100 μg/ml of palladium in 3 mol/l sulfuric acid as a matrix modifier is measured by graphite furnace AAS equipped with a polarized d.c. Zeeman-effect background-correction system. Spectral interferences were observed when both biological powdered samples or the above-mentioned solution samples were measured. The degree of the spectral interferences depended on the amounts of potassium coexisting in the samples. When the amounts of potassium coexisted at more than ca. 30 μg, the molecular absorbance at 196.0 nm increased tenfold compared with the certified values for the certified reference materials. It was considered that the spectral interferences were caused by the molecular absorption, such as potassium sulfide or potassium chloride, because it was not observed when a sample solution containing potassium nitrate was measured.
