Sugar-, acid- and phenol contents in apple cultivars from organic and integrated fruit cultivation

OBJECTIVE

This study was carried out to obtain data about the sugar-, acid- and phenol content of apple cultivars from organic and integrated fruit cultivation, with reference to their role in human health and especially for diet recommendations.

SETTING

Styria (Austria) and Slovenia.

INTERVENTIONS

HPLC, Spectral Photometry, organoleptic and olfactory tests.

RESULTS

The total sugar content of most cultivars from integrated cultivation ranged between 115 and 160 g/kg. Some cultivars from organic growing reached higher values. The acid content of both cultivar types was similar. The phenol content in organically grown cultivars was much higher than that of the ones from integrated cultivation.

CONCLUSION

Knowledge of the sugar content is very important for diabetic patients, owing to the assumption of general diet recommendations that 100 g fruit contain 12 g carbohydrates. This applies to most well-known cultivars like Golden Delicious or Gala, but not to most of the regional cultivars. For diabetics, it is necessary to know the carbohydrate content of food precisely, in order to adapt the amount of insulin to the ingestion. So, it is helpful to know the sugar content of each regional cultivar. Moreover, very high levels of phenolic compound in organically grown cultivars, and with it its importance for human health leads to the recommendation to eat regional fruits from organic fruit growing instead of those grown under integrated cultivation.

Separation of samarium and europium by solvent extraction with an undiluted quaternary ammonium ionic liquid: towards high-purity medical samarium-153

Long-lived europium-154 impurities are formed during the production of medical samarium-153 in a high-flux nuclear reactor. A method to separate these europium impurities from samarium was investigated using the hydrophobic quaternary ammonium ionic liquid Aliquat 336 nitrate. The separation method consists of the selective reduction of Eu3+ by zinc metal in an aqueous feed solution containing a high nitrate salt concentration. Subsequent extraction using undiluted Aliquat 336 nitrate leads to an efficient separation of both lanthanides in a relatively short time frame. Sm3+ was extracted to the neat ionic liquid phase much more efficiently than Eu2+. An initial approach using the addition of dicyclohexano-18-crown-6 to capture Eu2+ in the ionic liquid phase was less efficient.

Stability of europium(ii) in aqueous nitrate solutions

In the lanthanide series, Eu3+ is most easily reduced to its divalent state. Reduction of Eu3+ has been studied extensively in aqueous media that are insensitive to reducing conditions. Recently, it has been reported that reduction of Eu3+ is also feasible in aqueous nitrate solutions and that Eu2+ remained sufficiently stable in these media to conduct separation experiments. However, additional fundamental research on the reduction efficiency of Eu3+ and stability of Eu2+ in these media has not been reported yet. In this paper, cyclic voltammetry, magnetic susceptibility measurements, UV-vis absorption spectroscopy and X-ray absorption near edge structure (XANES) spectroscopy were used to gain more insights into the reduction of Eu3+ in aqueous nitrate media. Within the parameters used in this work, near-quantitative reduction of Eu3+ could be achieved within 120 min in highly concentrated nitrate salt solutions, using both chemical and electrochemical reduction techniques. Moreover, Eu2+ was remarkably stable in these solutions, showing just a small percentage of back-oxidation after 5 h in a sealed measurement cell.

Selective extraction of trivalent actinides using CyMe4BTPhen in the ionic liquid Aliquat-336 nitrate

The extraction of Am(iii), Cm(iii) and Eu(iii) by 2,9-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-1,2,4-benzotriazin-3-yl)-1,10-phenanthroline (CyMe₄BTPhen) from nitric acid solution was studied using the ionic liquid Aliquat-336 nitrate ([A336][NO₃]) as diluent. Results show a high selectivity of the solvent for Am(iii) and Cm(iii) over Eu(iii), but rather slow extraction kinetics. The kinetics of CyMe₄BTPhen were largely improved by the addition of 0.005 mol L^-1 N,N,N',N'-tetra-n-octyl-diglycolamide (TODGA) as a phase transfer reagent and by the use of 1-octanol as co-diluent. The addition of the phase transfer catalyst and co-diluent did not compromise the selectivity towards the actinide/lanthanide separation and thus this four-component system can be successfully applied to separate Am(iii) and Cm(iii) from the lanthanides.

Thorium-229 quantified in historical Thorium-228 capsules

Thorium-229 is a valuable, but scarce, radionuclide for nuclear clock applications or targeted alpha therapy. While it is mostly produced by the decay of ²³³U, ²²⁹Th can also be produced by neutron irradiation of ²²⁶Ra. At SCK•CEN, capsules containing mainly ²²⁸Th (by-product of ²²⁶Ra irradiation) were characterized to quantify the present amounts of ²²⁹Th, ²²⁸Th, ²²⁷Ac, ²²⁶Ra with high resolution gamma spectroscopy, after a decay period of 40 years in which ²²⁸Th has decayed. High purity ²²⁹Th was quantified, and after recovery using radiochemical separation processes, it can be used to support ongoing research.

Gamma radiolytic stability of the novel modified diglycolamide 2,2'-oxybis(N,N-didecylpropanamide) (mTDDGA) for grouped actinide extraction

Reprocessing of spent nuclear fuel aims at improving resource efficiency and reducing its radiotoxicity and heat production in the long term. The necessary separation of certain metal ions from the spent fuel solutions can be achieved using different solvent extraction processes. For the scenario of the EURO-GANEX process, the use of the new, modified diglycolamide 2,2′-oxybis(N,N-didecylpropanamide) (mTDDGA) was recently proposed to simplify the current solvent composition and reduce extraction of fission products. Before further developing the process based on this new ligand, its stability under ionizing radiation conditions needs to be studied. For this reason, gamma irradiation experiments were conducted followed by analyses with high performance liquid chromatography coupled to a mass spectrometer (HPLC-MS). The determined degradation rate of mTDDGA was found to be lower than that of the reference molecule N,N,N′,N′-tetra-n-octyl-diglycolamide (TODGA). Many identified degradation compounds of both molecules are analogues showing the same bond breaking, although also unreported de-methylation, double/triple de-alkylation and n-dodecane addition products were observed.

The radiolysis behavior of a new diglycolamide for solvent extraction of actinides and lanthanides was studied. The observed degradation rate was lower than for the reference molecule and 22 degradation compounds were identified.

Separation of terbium as a first step towards high purity terbium-161 for medical applications

Terbium-161 is a medical radiolanthanide that has a beta decay energy and half-life similar to that of lutetium-177, which makes it a promising alternative for therapeutic purposes. The production route using an enriched gadolinium-160 target necessitates the purification of terbium-161 from the untransmuted target material as well as from its stable decay product, dysprosium-161. The separation of neighbouring lanthanides is challenging due to their similar chemical properties and prominent trivalent oxidation states. In this work, the aim is to change the oxidation state of terbium, resulting in the altering of chemical properties that ease the intragroup separation. To this end, a novel separation method is investigated, involving the electrochemical oxidation of terbium (3+) to terbium (4+) followed by anion exchange chromatography. The electrolysis conditions are set to the highest achievable conversion rate, followed by a dilution step during which the pH and electrolyte concentration are slightly lowered to obtain conditions that are compatible with the separation method. XAS analysis is done to characterize the carbonato complex of both oxidation states and to further elucidate the separation mechanism. The results show that the separation approach of combining electrochemical oxidation with anion exchange chromatography is promising for the purification of 161Tb for medical use.

Improving Americium/Curium Separation Factors in the AmSel Process through Symmetry Lowering of the Diglycolamide Extractant

Partitioning and transmutation are important strategies for closing the nuclear fuel cycle. The diglycolamide extractant TODGA has played a major role in the development of solvent extraction processes for nuclear fuel reprocessing due to its good extraction performance, its hydrolytic and radiolytic stability, and its compliance with the CHON principle. However, due to drawbacks such as the tendency to form a third phase during extraction if no phase modifiers are used, continued research on diglycolamide-type extractants has led to the development of diglycolamides with decreased symmetry. In this study, it is shown that the recently developed diglycolamide, N,N-diisopropyl-N',N'-didodecyldiglycolamide (iPDdDGA), is a potential alternative to TODGA with improved separation between Am and Cm or the Ln. Using the AmSel system as a reference, the extraction kinetics, influence of the acid concentration, influence of the iPDdDGA concentration, and influence of temperature were evaluated. Slope analysis indicates similar average stoichiometries for iPDdDGA and TODGA complexes, but the extraction efficiency of iPDdDGA is orders of magnitude higher. The feasibility of selective americium stripping in combination with the hydrophilic sulfonated bis-triazinyl bipyridine SO3-Ph-BTBP complexant was demonstrated. Selective stripping of americium was found to be possible, and the use of iPDdDGA gave an unexpected improvement in Am/Cm separation, with SFCm/Am values of up to 3.0. This represents a small but significant improvement compared to the 2.5 value typically found for TODGA, and it demonstrates the potential of this solvent extraction system to improve existing processes based on diglycolamide-type extractants.

Extraction and speciation studies of new diglycolamides for selective recovery of americium by solvent extraction

Much research has gone into the development of extraction processes capable of separating minor actinides from highly active raffinates generated by the PUREX process. In particular, the separation of americium from curium remains challenging because of the similarity of their chemical properties. A new class of diglycolamide extractants called "unsymmetrical" diglycolamides (UDGAs), which contain at least two different alkyl chains, have recently been shown to have potential for improving the Am/Cm selectivity. However, the influence of the alkyl chains on the extraction efficiency and selectivity, and the formed complexes are not fully understood yet. For this purpose, using the AmSel system as reference, six UDGAs were studied by performing both extraction experiments and speciation studies, and compared to the benchmark extractant TODGA. The tested UDGAs all contain two dodecyl chains on one of the amide nitrogen atoms, and either two n-propyl, isopropyl, n-butyl, isobutyl, or n-pentyl chains, or a piperidine group on the opposing nitrogen atom. The results show that all of the tested UDGAs have equal or higher distribution ratios than TODGA, with the isopropyl derivative showing the most efficient extraction of Ln(iii) and An(iii). Selectivity for curium over americium was equal or higher in comparison with TODGA, with isopropyl and piperidine giving the highest separation factors, followed by pentyl, and the remaining UDGAs showing similar selectivity to TODGA. Speciation experiments of the complexes formed in the organic phase with neodymium were performed using FTIR, ESI-MS, and UV-vis spectrometry. This revealed very similar spectra for all of the diglycolamides, indicating no difference in the extraction mechanism.