DETERMINATION OF BA, CA, AND SR IN ALUMINUM-OXIDE AND ALUMINUM OXIDE-BASED SINGLE-CRYSTALS BY ATOMIC-EMISSION SPECTROMETRY

Conditions for the analysis of aluminum oxide and single crystals of w hite sapphire by atomic emission spectrometry (AES) are optimized for the simultaneous determination of Ba, Ca, and Sr by their atomic and i on emission spectral lines (Ca 422.6 nm, Sr 460.7 nm, and Ba 455.4 nm, respectively). The vaporization of test samples into an are discharge is carried out under conditions of the carbothermic reaction in the e lectrode crater (an IVS-28 type generator and a current of 16 A). In o rder to stabilize the are discharge, and to optimize the temperature m ode in the source of excitation, NaCl is evaporated as a 5% mixture wi th graphite from the counter electrode. Spectrograms are treated using a computer-driven MD-100 microphotometer with a special program that calculates the results of analysis by a calibration plot and by the st andard-addition method. The determination limits are 5 x 10(-5)% for S r and Ba, and 5 x 10(-4)% for Ca, respectively.