Flame Photometric Investigation of the Factors Affecting the Emissivity of Metal Chelates
The purpose of this project is to investigate some of the factors that affect the emissivity of metals when solutions of their chelates in organic solvents are aspirated into a flame. Solvent extraction methods were used to prepare the solutions of the beryllium, iron, and manganese chelates that were investigated. The following reagents were used to produce the corresponding chelate of each of the metals: 8-quinolinol, 4,4,4-trifluoro-l-(2-thi-enyl)-l,3-butanedione, sodium diethyldithiocarbamate, salicylaldoxime and the ammonium salt of N-nitrosophenylhydroxylamine. Toluene, chloroform, 4-methyl-2-pentanone, and pentyl acetate were used as extraction solvents.
Studies were carried out to determine the optimum combustion conditions for each of the organic extracts. Emission readings were taken as follows: at 470.9 mμ for the BeO bandhead, at 372.0 mμ for the iron line, and at 403.3 mμ for the unresolved triplet of manganese. The effect of the aspiration rate of the sample upon the emission intensity of each of the metals was investigated. The control of the rate of aspiration of the sample independent of the oxygen flow rate was accomplished by using several atomizer burners with capillary tubes of different diameters. These studies made it possible to establish a set of operating conditions for organic aerosols so that a fifty-eight-fold enhancement in the emission intensity of the BeO bandhead was obtained.
KeywordsEmission Intensity Metal Chelate Organic Extract Ammonium Salt Oxygen Flow Rate
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