No abstract

No abstract

Porphyrin ligands, showing a significant affinity for cancer cells, also have the ability to chelate metallic radioisotopes to form potential diagnostic radiopharmaceuticals. They can be applied in single-photon emission computed tomography (SPECT) and positron emission tomography (PET) to evaluate metabolic changes in the human body for tumor diagnostics. The aim of this paper is to present a short overview of the main metallic radionuclides complexed by porphyrin ligands and used in these techniques. These chelation reactions are discussed in terms of the complexation conditions and kinetics and the complex stability.

The present study investigates the sorption behavior of oxidized multiwalled carbon nanotubes (CNTs-COOH) for the separation and removal of scandium ions from aqueous solutions. The results indicated that CNTs-COOH showed an excellent scandium adsorption capacity of 40.1 mg g −1 (at pH 3) with an uptake time less than 2 min. The pseudo-second-order kinetic model and the film diffusion are the main controlling factors.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Searching for new compounds and synthetic routes for medical applications is a great challenge for modern chemistry. Porphyrins, natural macrocycles able to tightly bind metal ions, can serve as complexing and delivering agents in nuclear medicine diagnostic imaging utilizing radioactive nuclides of copper with particular emphasis on 64Cu. This nuclide can, due to multiple decay modes, serve also as a therapeutic agent. As the complexation reaction of porphyrins suffers from relatively poor kinetics, the aim of this study was to optimize the reaction of copper ions with various water-soluble porphyrins in terms of time and chemical conditions, that would meet pharmaceutical requirements and to develop a method that can be applied for various water-soluble porphyrins. In the first method, reactions were conducted in a presence of a reducing agent (ascorbic acid). Optimal conditions, in which the reaction time was 1 min, comprised borate buffer at pH 9 with a 10-fold excess of ascorbic acid over Cu2+. The second approach involved a microwave-assisted synthesis at 140 °C for 1–2 min. The proposed method with ascorbic acid was applied for radiolabeling of porphyrin with 64Cu. The complex was then subjected to a purification procedure and the final product was identified using high-performance liquid chromatography with radiometric detection.

No abstract

No abstract

In this study the identification, determination and distribution of metallic and radionuclidic contaminants in the synthesis of 18 F-fluorodeoxyglucose are presented. Samples of irradiated 18 O-enriched water, purification columns (anionic, C18, Al 2 O 3 ), final product and wastes were examined. Metallic contaminants were determined by ICP-MS and the radionuclide impurities by high resolution germanium gamma-spectrometry. Fifteen radionuclides were identified in the samples. The enriched water contained cationic contaminants ( 55 Co, 56 Co, 57 Co, 58 Co, 57 Ni, 52 Mn, 7 Be) while the anionic ( 95 Tc, 95m Tc, 96 Tc, 183 Re) were mostly retained in the QMA column. The sources of contamination by metals and radionuclides were determined. Results obtained by ICP-MS generally confirmed the radionuclide distribution obtained by gamma spectrometry.