Experimental study on the reasons for low sensitivity and memory effects in the determination of lanthanum and samarium in graphite furnace atomic absorption spectrometry

Abstract

The reasons for low sensitivity and memory effects in the determination of lanthanum and samarium in graphite furnace atomic absorption spectrometry (GFAAS) have been investigated experimentally using X-ray diffraction analysis (XRD), Auger electron microscopy (AES), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The formation of refractory carbides of La and Sm on the graphite surface is an important reason for their low sensitivity and memory effects. A very high sensitivity has been achieved in the determination of samarium by tantalum probe atomization, but the intercalation of SmTaO 4 into tantalum surface leads to an abrupt decrease in sensitivity.