Longitudinal a.c. Zeeman AAS with a transverse heated graphite furnace

Abstract

A longitudinal a.c. magnet has been constructed for Zeeman background correction in electrothermal atomization atomic absorption spectrometry (ETA-AAS). A 17-mm transverse heated graphite furnace with integrated contacts is operated in the 21-mm gap of the magnet. The Zeeman AAS system can be used in a 100-Hz background correction mode at a top magnetic field strength of 8 kG. Alternatively, when the shape of the magnetic field is changed to allow intensity measurements at three different strengths of the magnetic field, i.e. zero field, intermediate field strength and top field strength, an additional analytical curve of reduced slope is obtained. In the 3-field Zeeman system the dynamic range of Zeeman analytical curves is extended with a factor of about five. Both analytical curves are corrected for background absorption and can be obtained within one run of the standards. Experimental results obtained with the transverse heated graphite furnace show that characteristic mass data are similar to the corresponding data obtained with a conventional furnace.