QUALITY-CONTROL OF HOLLOW-CATHODE LAMPS IN ZEEMAN GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROMETRY

It has been experimentally established that the differences in the characteristic masses, m0, of elements atomized under the same conditions can be related to the differences in self-absorption of emission lines in hollow cathode lamps (HCL). When using Zeeman-corrected spectrometers, the self-absorption can be checked by measuring the roll-over absorbance. A(R), and, in some cases, the Zeeman sensitivity ratio, R(Z). An experimental study of the relations m0 = f(A(R)) and m0 = f(R(Z)) for the Cu 324.8 nm, Ag 328.1 nm, and Co 240.7 nm lines has shown that the use of the parameter A(R) is preferable. It has been established that most of the scatter of the values of m0 for Cu and Ag in an inter-laboratory investigation (I. L. SHUTTLER, G. SCHLEMMER, G. R. CARNRICK and W. SLAVIN, Spectrochim. Acta 46B, 583, 1991) is primarily due to differences in the HCL spectral characteristic. Recommendations are given on operating the HCLs to prevent such a scatter in the values of m0.