Direct current plasma as an excitation source for flame atomic fluorescence spectrometry - some applications

The concentrations of Mn, Cr, Cu and Co were accurately determined in various standard steel samples, as were Mn, Cu, Zn and Fe in tomato leaves and bovine liver (National Bureau of Standards reference materials). Scatter signals were evaluated by means of the two-line method. Various potential spectral interferences were studied including the effect of 5000 mu g/ml Fe solutions on Mn and Cr determinations. The plasma behaved as would be expected of a narrow line source. The two-electrode version of the direct current plasma that was used limited the precision of the measurements to 10% relative standard deviation. 18 ref.--AA