Ionization interferences under various operating conditions in a 9, 27 and 50 MHz ICP, and a study of shifts in level populations of calcium through simultaneous absorption-emission measurements in a 9 MHz ICP

Elemental matrix effects in ICP-AES

“…Moreover, each variable can influence the analyte excitation mechanism in a different fashion. 12 As has been mentioned previously, among the most important variables affecting the matrix effects are the nebulizer gas flow rate, the rf power and the plasma observation height. 2 The analyte residence time depends on the gas velocity, which in turn is a function of the gas flow rate and the injector inner diameter.…”

“…[8][9][10][11] Sentences such as ''Studying the literature on these interferences in the ICP is a study of confusion'' accurately reflect the actual situation concerning these analytical problems. 12,13 Blades and Horlick 13 initially attributed this confusion to the inconsistency of the data that had appeared concerning these matrix effects, because some workers had found enhancements, depressions or no effects at all on the analytical signal when EIEs were present. In addition, there is no satisfactory mechanism explaining the way in which these interferences are produced.…”

Effect of Operating Frequency on Spatial Features of the Inductively Coupled Plasma

“…The 9 M Hz ICP, however, was sustained in a torch of m uch larger dimensions that required higher ow rates than did the 27 and 50 MHz plasmas. Gunter et al 5,6 found similar trends in analyte excitation temperature and electron number density with operating frequency as did Capelle et al 4 In addition, Webb and Denton 9 have compared a 148 MHz ICP with a 1-turn load coil to a 27 MHz ICP with a 2.5-turn load coil. They found that the two ICPs exhibited similar Fe(I) excitation temperatures and electron number densities.…”

“…Obtaining an unambiguous comparison of inductively coupled plasmas (ICPs) operated at different frequencies has in the past proven to be a dif cult task. Although evaluations have been carried out of analytical ICP systems operated at frequencies ranging from 5 to 148 MHz, [1][2][3][4][5][6][7][8][9] direct comparison of results obtained from these studies has often been suspect since in all cases at least one component of the system, frequently the radio-frequency (rf) power supply, is changed. Also, in all cases, it has not been possible to maintain the plasmas at the same or similar operating conditions.…”

“…Gunter et al 5,6 have examined plasmas operated at 9, 27, and 50 M Hz. The 27 and 50 MHz systems were operated under similar conditions.…”