The solution chemistry of the hydrolytic, early-transition-metal ions Ti and Sc represents a coordination chemistry challenge with important real-world implications, specifically in the context of Ti/Sc and Ti/Sc radiochemical separations. Unclear speciation of the solid and solution phases and tertiary mixtures of mineral acid, organic chelators, and solid supports are common confounds, necessitating tedious screening of multiple variables. Herein we describe how thermodynamic speciation data in solution informs the design of new solid-phase chelation approaches enabling separations of Ti and Sc. The ligands catechol (benzene-1,2-diol) and deferiprone [3-hydroxy-1,2-dimethyl-4(1)-pyridone] bind Ti at significantly more acidic conditions (2-4 pH units) than Sc. Four chelating resins were synthesized using either catechol or deferiprone with two different solid supports. Of these, deferiprone appended to carboxylic acid polymer-functionalized silica (CA-Def) resin exhibited excellent binding affinity for Ti across a wide range of HCl concentrations (1.0-0.001 M), whereas Sc was only retained in dilute acidic conditions (0.01-0.001 M HCl). CA-Def resin produced separation factors of >100 (Ti/Sc) in 0.1-0.4 M HCl, and the corresponding values (>1000) show strong retention of Ti. A model Ti/Sc generator was produced, showing 65 ± 3% yield of Sc in 200 μL of 0.2 M HCl with a significant Ti breakthrough of 0.1%, precluding use in its current form. Attempts, however, removed Sc in loading fractions and a dilute (0.4 M HCl) wash and recovered 80% of the loaded Ti activity in 400 μL of 6 M HCl. The previously validated Ti chelator TREN-CAM was used for comparative proof-of-concept reactions with the CA-Def eluent (in HCl) and literature-reported hydroxamate-based resin eluents (in citric acid). CA-Def shows improved radiolabeling efficiency with an apparent molar activity (AMA) of 0.177 mCi nmol, exceeding the established methods (0.026 mCi nmol) and improving the separation and recovery of Ti for positron emission tomography imaging applications.

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.inorgchem.3c01493DOI Listing

Publication Analysis

Top Keywords

speciation data
8
solid supports
8
acidic conditions
8
ca-def resin
8
μl hcl
8
mci nmol
8
hcl
7
novo approaches
4
approaches solid-phase
4
solid-phase separation
4

Similar Publications

Uranyl Speciation in Carbonate-Rich Hydrothermal Solutions: A Molecular Dynamics Study.

Inorg Chem

December 2024

State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China.

In this study, we employed classical molecular dynamics (CMD) and first-principles molecular dynamics (FPMD) simulations to investigate the speciation of uranyl in carbonate-rich hydrothermal solutions. The association constants (log) of uranyl carbonate complexes were derived from the potential of mean forces (PMFs) obtained from CMD simulations, and the acid constants (ps) of uranyl aqua ions were calculated using the FPMD-based vertical energy gap method. The results showed that uranyl ions could form stable mono- and bi-carbonate complexes at elevated temperatures and that uranyl aqua ions strongly hydrolyzed in neutral solutions at temperatures exceeding 473 K.

View Article and Find Full Text PDF

Prevalence and molecular characterization of Campylobacter spp. isolated from chicken, beef, pork and sheep livers at Irish abattoirs.

Int J Food Microbiol

December 2024

Food Microbiology Division, Department of Agriculture, Food and the Marine, Backweston Laboratories, Celbridge, Co. Kildare, Ireland.

Thermotolerant Campylobacter spp. are the leading causes of food-borne diarrhoea in humans with most cases attributed to C. jejuni, and C.

View Article and Find Full Text PDF

Organic compounds in valley fogwater in North and Mount Lebanon during COVID-19 period.

Sci Total Environ

December 2024

Institute of Chemistry and Processes for Energy, Environment and Health ICPEES UMR 7515, University of Strasbourg, F-67087 Strasbourg Cedex 3, Strasbourg, France. Electronic address:

Caltech Active Strand Cloudwater collectors are used to collect valley fog samples from Mount and North-Lebanon during 2021 for the speciation of organic matter for the first time ever. Numerous compounds including pesticides, phenols, acids, and persistent organic pollutants such as polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polycyclic aromatic hydrocarbons (PAHs) have been identified in fogwater samples. They are extracted using the liquid-liquid extraction performed on the XTR chromabond columns.

View Article and Find Full Text PDF

Background: Existing software for comparison of species delimitation models do not provide a (true) metric or distance functions between species delimitation models, nor a way to compare these models in terms of relative clustering differences along a lattice of partitions.

Results: Piikun is a Python package for analyzing and visualizing species delimitation models in an information theoretic framework that, in addition to classic measures of information such as the entropy and mutual information [1], provides for the calculation of the Variation of Information (VI) criterion [2], a true metric or distance function for species delimitation models that is aligned with the lattice of partitions.

Conclusions: Piikun is available under the MIT license from its public repository ( https://github.

View Article and Find Full Text PDF

Delimiting species boundaries is a perennial challenge in the field of systematics. Resolving whether morphological variation is the result of environmental parameters, incipient speciation, or complete speciation is especially challenging when the variation is subtle. Within the perennial endemic North American clade of Apiaceae (PENA) there are numerous examples in which widespread species have subtle geographically defined morphological variants that have typically been recognized at the subspecific rank.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!