Simple and Reliable Analysis of Uranium by the Application of Differential Technique in Laser-induced Fluorimetry/ Pulsed LED-Fluorimetry in Ores, Certification of Reference Materials, Borehole Core Assay, Beneficiation Product, and Other Diverse Matrices

The measurement of uranium in diverse matrices like mineralized rocks, ores, beneficiation products, and other diverse matrices using a Laser/LED fluorimeter, without resorting to any separation technique is presented and critically evaluated. The main emphasis is on advances and challenges in the available technique, RAP’s: Reliability, Applicability, and Practicability. Among fluorimetry techniques, Laser/LED fluorimeter is the technique of choice to fulfil the desired parameters by suitably selecting fluorescence-enhancing reagents and methods of measurement. Application of differential technique (DT) in laser-induced fluorimetry/ICP-OES for the direct determination of uranium is recommended for routine accurate determination of uranium over a wide range of concentrations, which is based on the comparison of the response of the standard with a sample of similar but unknown concentration on the same sample weight basis. Differential laser-induced fluorimetry method has been evaluated using standards, SY-2, SY-3, reference uranium ore, BL-2a, low-grade uranium ore-IAEA reference samples, and core samples of diverse matrices. The relative standard deviation of the method was 0.3–0.5% in nine replicates for 0.04–3.4% U3O8 in mineralized silicate rock samples and 0.5–0.9% at 18.1, 36.2, 61.2, and 99.6% U3O8 in concentrates and mineralized grab samples. In this approach, the procedure of elimination of interference by simple dilution of the sample has the distinct advantage of being quick and very simple to perform because it does not require any chemical preparation or extraction. The results are in good agreement with the published data and those obtained by conventional fluorimetry and other methods, and of comparable precision to those obtained by titrimetric assay. It is a self-standardized green methodology of measurement and guarantees the quality of an analytical result (Accuracy, high precision, reliability, comparability, and traceability). Application of differential technique in Laser-/LED-fluorimetry/ICP-OES has the inherent high metrological quality and will be useful for the analysis of uranium in ores, certification of reference materials, borehole core assay, beneficiation product, and other diverse applications in the entire nuclear fuel cycle worldwide.