VALIDATION OF THE METHOD FOR THE DETERMINATION OF RARE EARTH METALS IN BIOLOGICAL SAMPLES BY THE ATOMIC EMISSION INDUCTIVELY COUPLED PLASMA METHOD (ICP OES)

Abstract

Currently, one of the priority nanomaterials are nanoparticles of rare earth metals (RЕM) – cerium, lanthanum, gadolinium and others, which allows them to be successfully used as new natural feed additives (due to their antimicrobial and antioxidant properties) in order to increase the productivity of animals. However, the issue of redistribution in the body and accumulation of RЕMs in livestock products requires an adequate answer using sensitive and highly accurate quantitative research methods, in connection with which the determination of RЕMs in biological samples becomes extremely relevant. Within the framework of this study, the suitability assessment (validation) of the developed method for the determination of RЕM (lanthanum and gadolinium) in biological samples (serum, liver, kidneys) using atomic emission inductively coupled plasma (ICP OES) was carried out and the method of sample preparation in various matrices was adapted. Key working parameters were determined as evaluation criteria: limit of detection, limit of quantification, accuracy, correctness, convergence, reproducibility, selectivity, linearity, working range. It was established that this method demonstrates good linearity in the working range of 1.0-500.0 μg/kg(dm3) for Gadolinium and 0.5-500.0 μg/kg(dm3) for Lanthanum; the method is selective, sensitive, practical and accurate. The limit of detection LOD and limit of quantification LOQ for Gadolinium and Lanthanum are 0.1 and 0.05 μg/kg(dm3) and 1.0 and 0.5 μg/kg(dm3), respectively. The validation data obtained meet the requirements of the Eurachem Guideline and the IUPAC Harmonized Guideline for Single-Laboratory Validation, and the method for the determination of RЕMs in biological samples is suitable for a specific application according to ISO/IEC 17025:2019.