Portable Luminescence Based Fiber Optic Probe for REE Detection and Quantification

Abstract

A novel luminescence-based sensor was developed for the rapid, insitu detection and quantification of rare earth elements for potential applications in waste recovery. The device has the capability to detect μg/L (part-per billion) concentrations of several rare earths in aqueous solution within 1 min, and it is portable given a physical dimension of less than 1/2 m3. Whereas, conventional table-top devices used for this type of analysis are bulky and have high costs, in addition to the typical two week long processing times for laboratory analyses of rare earths. The rapid return of results that this portable and rugged device provides can save the end user the cost of inaction during recovery or mining operations, potentially allowing for “in line” monitoring or rapid field sampling. Luminescence sensitizers were used to lower the limit of detection of the rare earths in comparison with direct excitation, by approximately an order of magnitude. Examples of luminescence sensitizers tested include M(CN)2 (where M = Ag, Au, Cu) and 2,2 bipyridine.