| Abstract: | Atomic emission has been observed from 20 elements in an electrically heated graphite furnace. Two-line temperature measurements carried out on iron indicate an excitation temperature of ca. 2450 K when the temperature of the furnace walls is ca. 2420 K. Calibration curves have been obtained for Al, Mo and Cr, each showing a useful working range. The detection limit for Al was 5 pg, and for Cr and Mo was 140 pg. Bismuth was found to give a poor detection limit (10 ng). Time resolved traces of background emission and line emission intensity shows the validity of using the two-line method to measure the excitation temperature of iron. A thermal excitation mechanism of emission is proposed. |
