Deoxidation Effect of Carbon Black on Flame Atomic Absorption of Metals by Direct Atomization of Metal Oxides

Abstract

It has previously reported that interferences of phosphate or fluoride ions is eliminated by dispersing carbon black in the sample solution on the flame atomic absorption spectrophoto- metry of metals. This report deals with the investigation of the deoxidation effect which is considered as a reason of the elimination. Powder of metal oxides (Cu₂O, CuO, PbO₂, ZnO, ZnO₂) were used as samples of direct atomization, dispersed in the sample solutions with the carbon black, atomized and combustioned with a fuel gas.
The obtained absorbance was compared between the presence of carbon black and activated carbon or 1-butanol and the difference of the deoxidation effect was estimated. By the results, activated carbon and 1-butanol were less effective than carbon black and the difference of the effect were about 40∼50%. But lower absorbance was obtained for the flame atomic absorp- lion spectrophotometry of metal oxide powder by direct atomization with dispersing carbon black than that of general atomic absorptiometry for respective ions.