Quantification of Lanthanides in Rocks Using Succinic Acid-Derivatized Sorbents for On-Line SPE-RP-Ion-Pair HPLC

Abstract

The use of new poly(norbornene-block-7-oxanorborn-2ene-5,6-dicarboxylic acid)-coated silica-based sorbents as well as of beaded polymers based on poly(norborn-2-ene-5,6-dicarboxylic acid-co-1,4,4a,5,8,8a-hexahydro-1,4,5,8-exo-endo-dimethanonaphthalene) for the on-line preconcentration of lanthanides from rock digests and their subsequent RP-ion-pair HPLC separation is described. Block co-polymers of norborn-2-ene and 7-oxanorborn-2-ene-5,6-dicarboxylate used for coating were prepared by ring-opening metathesis polymerization (ROMP) and poly(norborn-2-ene-5,6-dicarboxylic acid-co-1,4,4a,5,8,-8a-hexahydro-1,4,5,8-exo-endo-dimethanonaphthalene)-based polymer beads were prepared by ring-opening metathesis precipitation polymerization. Both types of sorbents exhibit an extraordinarily good pH stability, are hydrophilic and therefore easily wetable by water alone, and show high extraction efficiencies for lanthanides within a pH of 3.5-5.5. The rare earth element (REE) content in the investigated rocks varied over 3 orders of magnitude (0.19-108 microg/g). REE concentrations prior to enrichment were typically in the range of 1-25 ng/mL; the total amount of each REE sorbed onto the precolumn was in the range of 8-270 ng. Extraction selectivities of the sorbent may be enhanced by adding 5-sulfosalicylic acid as a masking agent for iron and aluminum as well as methanol as an inhibitor for the precipitation of o-silicic acid. Gradient elution of the lanthanides from the precolumn and their subsequent separation on a RP-C18 column was achieved using hydroxyisobutyric acid (HIBA) and sodium octanesulfonate. Depending on the actual concentration of the lanthanides in the digests and in order to suppress interfering cations, UV detection was carried out with two different postderivatization reagents, 4-(2-pyridylazo)resorcinol (PAR) and arsenazo III. The high selectivity in enrichment as well as the complementary use of post-derivatization reagents allows the fast, quantitative, and highly reproducible quantification of REEs present in rocks by complete removal or suppression of all other interfering components. Thus, recoveries were found to be within a range of 97-103% for most REEs with relative standard deviations of 2-5%.

Determination of Lanthanides, Thorium, Uranium and Plutonium in Irradiated (Th, Pu)O2 by Liquid Chromatography Using α-Hydroxyiso Butyric Acid (α-HIBA)

“…have been reported for the separation of Lns, Th, U and Pu in various matrices [10,11]. Among these methods, high performance liquid chromatography (HPLC) is a fast and highly efficient technique and has been applied for the separation of lanthanides and actinides in nuclear fuel samples and geological samples [12][13][14][15][16]. Due to the fast separation and less amount of the sample handling in HPLC, it minimizes the exposure to highly radioactive samples and is, therefore, attractive for the separation of fission products.…”

Transition metal-based polymer chemistry: a critical micro-review

“…Despite their name, these elements are not rare at all and are of great signi cance in the areas of highperformance materials including superconductors, petrogenesis [4,5], radioactive waste [6], and, of course, polymer chemistry [7]. The preferred oxidation state is +III, though Sm, Eu, Tm, and Yb can additionally assume the +II oxidation state, while Ce, Pr, and Tb also form stable tetra-valent compounds.…”

EBT anchored SiO23-D microarray: a simultaneous entrapper of two different metal centers at high and low oxidation states using its highest occupied and lowest unoccupied molecular orbital, respectively

“…Widely used solid phase (SP) sorbent, silica gel (SG), gets hydrolyzed at its working range of pH 7.5-8 [26] . Reported SP sorbents (like XAD resins, ion-exchange resin, cellulosic derivatives, and porous glass beads) [29][30][31][32][33] did not achieved appreciable selectivity to get the targeted species in its pure form by removing the interference of co-existing species. Reported SP sorbents (like XAD resins, ion-exchange resin, cellulosic derivatives, and porous glass beads) [29][30][31][32][33] did not achieved appreciable selectivity to get the targeted species in its pure form by removing the interference of co-existing species.…”