ATOMIC LINE-PROFILES - THEIR MEASUREMENT AND IMPORTANCE IN ANALYTICAL ATOMIC SPECTROSCOPY

Profiles of the resonance lines of Ag, Co, Hg, Mn, Mg and Pt, emitted by hollow cathode lamps (HCLs), have been measured for a range of currents using a scanning echelle monochromator. The effect on the calibration graph of self-absorption broadening or self-reversal due to higher currents is complex and is strongly influenced by the presence of isotope and hyperfine structure. The echelle monochromator has also been used to measure absorption linewidths and shifts in the air-acetylene flame, and results obtained for Ag, Li, Mg and Mn were found to be in good agreement with calculated values reported in the literature. For Li, the use of a semiconductor laser diode instead of a hollow cathode light source is shown to overcome some of the inherent disadvantages of the HCL and to provide improved sensitivity and better linearity.