Non-linearity and range of analytical curves in Zeeman-effect atomic absorption spectrometry

Analytical curves for Zeeman-effect atomic absorption spectrometry (ZAAS) can be used with up to double the amount of analyte when the absorbance is integrated. The shape of Zeeman analytical curves with integrated absorbance is similar to that of the corresponding curves in conventional AAS. The maximum of the useful concentration range, based on a criterion of a 4-fold reduction in the initial slope of the curve, is the same for AAS and ZAAS. Similarly to conventional AAS, the sensitivity of ZAAS is enhanced by the application of narrower lamp emission profiles whereas the shape of the curve is almost independent of the lamp current. A 5–10-fold wider dynamic range is available in ZAAS when a three-field a.c. Zeeman instrument is used.