Mutual Interference Effects of Certain Group III-A Ions with Calcium in Flame Spectroscopy

Abstract

The reduction in emission intensity of calcium due to the presence of BO₃ ⁻³, Al⁺³, Ga⁺³ and In⁺³ in the test solutions has been determined. The reverse effect, i.e., the effect of calcium on emissions of Group III-A elements also has been determined. Sample dilution decreased BO₃ ⁻³ suppression but increased Al⁺³ suppression of calcium radiations. Apparently n-butanol forms a compound with the BO₃ ⁻³ ion in the evaporating aerosol droplet. This results in an increase in the band emissions owing to an excited state of the boron oxide in the flame, and effects a release of boron suppression of calcium radiations. The presence of methanol (10 to 50% by volume) and sucrose (1%) in the test solution decreases the effect produced by BO₃ ⁻³ but increases the effect of aluminum on calcium radiations. Difference in the degree of suppression of the Ca (I) line and CaO bands due to the presence of BO₃ ⁻³ or in the test solutions cannot be accounted for on the basis of an intermediate refractory solid phase. The effects of Ga⁺³ and In⁺³ on calcium radiations can best be explained in terms of a gas-phase suppression mechanism. In these studies both H₂—O₂ and C₂H₂—O₂ fuel systems have been used.

Contribution No. 624, Department of Chemistry, Kansas State University. Abstracted from a dissertation submitted by the senior author to the faculty of Kansas State University in partial fulfillment of the requirements for the Ph. D. degree. Supported in part, by National Institute of Health Grant No. GM-08524. Present address; Phillips Petroleum Co., Research Center, Bartlesville, Oklahoma.