Determination of rare earth elements in natural water samples – A review of sample separation, preconcentration and direct methodologies

Abstract

This review discusses and compares the methods given for the determination of rare earth elements (REE) in natural water samples, including sea, river, lake, tap, ground and waste waters as well as Antarctic ice. Since REE are at very low concentrations in natural waters, numerous different preconcentration methods have been proposed to enable their measurement. These include liquid liquid extraction, dispersive liquid-liquid micro-extraction and solidified floating drop micro-extraction. In addition to liquid-liquid extraction methods, solid phase extraction using commercial resins, resins made in-house, silica-based exchange materials and other solid media is also discussed. These and other techniques such as precipitation/co-precipitation and flotation are compared in terms of speed, preconcentration factors achieved, precision, accuracy and limits of detection (LOD). Some papers have discussed the direct determination of REE in these sample types. Some have used specialised sample introduction systems such as ultrasonic nebulization whereas others have used a standard sample introduction system coupled with inductively coupled plasma mass spectrometry (ICP-MS) detection. These direct methods have also been discussed and compared.

Gadolinium as an Emerging Microcontaminant in Water Resources: Threats and Opportunities

“…LA patterns are thought to be great indicators of overall river basin processes (e.g., chemical weathering and transportation processes) due to the relative consistency of physicochemical properties and bedrock types within a river; except in cases where either atmospheric wet and dry deposition or anthropogenic lanthanides significantly alters the dissolved LA load by orders of magnitude [19,[72][73][74]. Due to this invariable coherent behavior in biogeochemical processes, LA patterns are a prevalent geochemical tool for the interpretation of the dissolved load content of natural waters [24,[75][76][77]. Table 2.…”

Biogeochemical Cycle of Lanthanides in a Light Rare Earth Element-Enriched Geological Area (Quebec, Canada)

“…Rare earth elements (REEs) comprise the lanthanide group from lanthanum (atomic number, Z = 57) to lutetium (Z = 71) as well as two transition elements: yttrium (Z = 39) and scandium (Z = 21) [1]. They are naturally present in the environment, where they form a chemical group [2] of similar characteristics.…”

Preconcentration of Lutetium from Aqueous Solution by Transcarpathian Clinoptilolite

“…7 That is why the determination of Ln in natural waters is important not only from the point of view of analytical chemistry, but also geochemistry, oceanography, and natural science. [8][9][10][11][12] Ln are present in natural objects in small quantities, so often the preliminary treatment of samples is applied for their determination, which in particular includes preconcentration, separation, and exclusion. [13][14][15][16] The sufficient number of highly sensitive and selective methods of analysis for the detection and quantitative determination of Ln is not available.…”