Atomic magneto-optical rotation spectroscopy (AMORS) using a Wollaston prism as analyser and beam splitter

Abstract

An electrothermal atomisation Faraday configuration atomic magneto-optical rotation spectrometer has been constructed. The apparatus incorporated a hollow-cathode lamp as light source, a Glan polarising prism, a segmented rod atomiser in a longitudinal magnetic field and a Wollaston prism, with its optical axis at 45° to that of the polariser, serving as an analyser and producing two optical beams of orthogonally polarised radiation. The two optical beams were passed alternately to a grating monochromator with associated electronics and computer for measurement. A theoretical study of the generation of the optical rotation signal was undertaken. Cadmium, copper and silver were determined in simple aqueous solutions. The magnetic field dependence of the signal was studied. Detection limits, which were not as low as predicted theoretically, were comparable to those in Zeeman-effect atomic absorption spectrometry using the same instrument. The linearity of calibration graphs was restricted by dichroic effects to an upper limit of analyte mass of ca. 20 times the detection limit.