Radanal (Czechia)

A novel method has been developed for the simultaneous determination of difficult-to-measure (DTM) nuclides 93Zr, 237Np, 232Th, 230Th and 228Th using a DGA resin® (containing N,N,N′,N′-tetra-n-octyl-diglycolamide) column for simultaneous separation of Zr and actinides followed by purification of Zr, Np and Th on a TEVA resin® (containing Aliquat 336) column. Samples are destroyed by fusion with sodium hydroxide or by acid destruction using HNO3, HCl and HF. Pre-concentration procedure tailored to the extraction chromatography is based on co-precipitation of Zr and actinides and removal of alumina, silica, iron and calcium. The concentrations of 93Zr, 237Np and Th nuclides are determined by ICP-MS and α spectrometry, respectively. High chemical recoveries (≥ 73%) and separation factors were obtained for Zr, Np and Th both in evaporation concentrates of an NPP and various samples of mineral origin such as soil and concrete. The procedure can be easily combined with the simultaneous separation of other actinides (Pu, Am, U) using the same DGA column that has been described in our previous papers (Cassette et al. in Appl Radiat Isot 68:122–130, 2010 and Groska et al. in J Radioanal Nucl Chem 309(3):1145–1158, 2016).

Abstract Electrochemistry combined with mass spectrometry represents an emerging analytical technique used to study the oxidation pathway of various drugs and in vivo occurring compounds, continuously showing a capability to generate many known metabolites or new oxidation products. An on‐line HPLC/EC/HR ESI‐MS method had been used to investigate the oxidation of selected cytokinin compounds. This setup allowed rapid identification and general structure elucidation of the obtained products. An electrochemical oxidation of isopentenyladenine resulted in five products, including hydroxylated and dehydrogenated products, which correlates very well with its in vivo metabolism. Electrochemical conversion of trans‐zeatin revealed six products, with two dehydrogenation products corresponding to its in vivo occurring metabolites. cis‐Zeatin oxidation in the electrochemical cell gave rise to eight products, resembling similarity to trans‐zeatin oxidation. All three compounds underwent a complete turnover mainly through two oxidation reactions occurring in the electrochemical celldehydrogenation and a less typical aliphatic hydroxylation. The resulting products are in correlation with their known in vivo metabolism.

Zbornik znanstvenih radova Vladan Desnica i Split (1920. – 1945.) sadržava članke koji su nastali na temelju priopćenja s Desničinih susreta 2014., održanih u Splitu 19. i 20. rujna te u Islamu Grčkom 21. rujna 2014. godine. Potpisani urednici osjećaju potrebu naglasiti da su za uspješan rad skupa, bitnu pretpostavku za nastanak ovog zbornika, zaslužni kolege s Filozofskog fakulteta Sveučilišta u Splitu, a naročito prof. dr. sc. Aleksandar Jakir, dekan Filozofskog fakulteta, koji je i sam bio sudionik skupa. Sedamnaest od devetnaest sudionika preradilo je svoja priopćenja u članke. Njihovi su radovi prije svega svjedočanstva vlastitih istraživanja, ali oni zrcale i učinke nerijetko pasionirane pa i vrlo polemične rasprave na samom skupu. Najviše se raspravljalo, dakako, o Vladanu i dr. Urošu Desnici, potom o drugim, najčešće znamenitim Splićanima tog doba, ali i o splitskim pučanima te o tadašnjoj velikoj urbanoj transformaciji Splita, licu i naličju kulturnih i umjetničkih inovacija trajne vrijednosti, koje su i bile u središtu pozornosti.

The majority of long-lived radionuclides produced in the nuclear fuel cycle can be regarded as “difficult-to-measure” nuclides, hence chemical separation is needed before the nuclear measurement of them. A combined radiochemical procedure that enables the simultaneous determination of some “difficult-to-measure” nuclides in medium and low level radioactive wastes has been developed in our laboratory. Recently, this method has been extended for determination of 237Np and 93Zr. 237Np and 93Zr are pre-concentrated by co-precipitation on iron(II) hydroxide and zirconium oxide, separated by extraction chromatography using UTEVA, and measured by inductively coupled plasma mass spectrometry (ICP-MS). As even traces of polyatomic ions and isotopes at m/z 237 or 93 cause considerable interferences during ICP-MS detection, a purification step by extraction chromatography was needed. Analyzing real samples (evaporation concentrates of a nuclear power plant) 66–99% and 31–99% chemical yields were achieved for Np and Zr, respectively.