A stable method for ionic rare earth element extraction and quantitative analysis of total quantity and composition of batch samples†

Abstract

The development of a stable, high-precision and batch ion-adsorption rare earth element detection method is highly anticipated in the delineation and evaluation of the mining value of rare earth element mines. In this study, a novel mixed extractant of ammonium sulfate + ammonium citrate + aceto-sodium acetate buffer was used to significantly improve the extraction efficiency of rare earth elements. Following a series of parameter optimizations, an off-line internal standard addition method and the collision mode of the inductively coupled plasma-mass spectrometer were used to improve the detection efficiency for batch samples, effectively eliminating oxide interference between the rare earth elements and improving the detection accuracy. The detection limit for ion-adsorption rare earth elements was 3.4 μg g⁻¹ and the detection range was 12–8000 μg g⁻¹. More importantly, the spiked and recovery experiments carried out in multiple laboratories with internal quality control samples show that the relative deviation was −5.61 to 3.79%, which indicates that the method has sufficient stability. Establishment of this method will help to improve the comprehensive utilization efficiency of rare earth resources and provide important support for rare earth element mining.