Characterization of a laboratory-constructed cathodic sputtering atomizer for direct determination of solid samples

Abstract Effects of changes in applied power, discharge gas pressure and flow rate on atomic absorption and emission signals obtained from a jet-assisted cathodic sputtering atomizer were investigated. The absorbance of nickel sputtered from iron and brass samples and the emission intensities of a copper resonance line (Cu I 324.8 nm) and an ion line (Cu II 224.7 nm) were measured. With increasing flow rate of the discharge gas (argon), the emission intensity of the copper resonance line reached a maximum and then decreased with further increase in the flow rate, whereas the emission intensity of the ion line continued to increase. This behaviour indicates that the Cu I 324.8 nm resonance line is self-absorbed with increasing argon flow rate. Self-absorption is caused by an increase in the number of ground-state atoms in the light path. This increase is a result of a decrease in redeposition of sputtered copper atoms and an increase in the absorption path length. High-resolution Fourier transform spectroscopic measurements were made for the Cu I 324.8 nm resonance line as well as for the Fe I 248.3 nm resonance line. Both lines were found to be self-reversed.