Trace metal determinations by monitoring modulated magnetically induced optical rotation in atomic vapours

Abstract

A new atomic magneto-optical rotation spectrometer (AMORS) for the determination of trace metals is described. This instrument differs from previous AMORS devices by utilising an electronically variable optical retardation element to modulate the polarisation and a phase meter for detection of the analytical signal. Preliminary detection limits for Li, K and Mg are comparable to those reported for atomic absorption spectrometry under similar analysis conditions. Further, this method of signal detection is insensitive to changes in the light intensity transmitted through the atomiser. Experimental evidence suggests that the spectral band width of the radiation source and the range over which the optical retardation element is varied can significantly affect the detection limits.