Flame emission studies of several metal chlorides with vapor-phase sampling

A method is described for the production of spectra of aluminum chloride, iron(III) chloride, silicon tetrachloride and titanium tetrachloride vapors by flame emission spectrometry. The aluminum and iron(III) chloride vapors were prepared by heating solid samples in reaction flasks; silicon and titanium tetrachlorides have sufficient vapor pressures at ambient temperatures to produce vapor-phase samples. Techniques have been developed to introduce the sample into the flame as a vapor, and to accommodate a large concentration of sample while requiring minimum preparation. Spectra were obtained individually and as a mixture over 240–600 nm. The analytical wavelength was chosen for each element, and 10-s integrations were made by utilizing a microcomputer to slew rapidly to the line of interest, hold for 10 s on the emission line, move off wavelength, hold for a 10-s background measurement and slew rapidly to the next line of interest. The microcomputer was also used to digitize and display the number of photons counted.