Please find here under a short list with recently published papers on the use of extraction chromatography that we'll update frequently. We hope that this will be of help for your work!
Riga et al. "Production of Ga-68 with a General Electric PETtrace cyclotron by liquid target"
In recent years the use of 68Ga (t1/2 = 67.84 min, β+: 88.88%) for the labelling of different PET radiopharmaceuticals has significantly increased. This work aims to evaluate the feasibility of the production of 68Ga via the 68Zn(p,n)68Ga reaction by proton irradiation of an enriched zinc solution, using a biomedical cyclotron, in order to satisfy its increasing demand.
Irradiations of 1.7 M solution of 68Zn(NO3)2 in 0.2 N HNO3 were conducted with a GE PETtrace cyclotron using a slightly modified version of the liquid target used for the production of fluorine-18. The proton beam energy was degraded to 12 MeV, in order to minimize the production of 67Ga through the 68Zn(p,2n)67Ga reaction. The product’s activity was measured using a calibrated activity meter and a High Purity Germanium gamma-ray detector.
The saturation yield of 68Ga amounts to (330 ± 20) MBq/µA, corresponding to a produced activity of 68Ga at the EOB of (4.3 ± 0.3) GBq in a typical production run at 46 µA for 32 min. The radionuclidic purity of the 68Ga in the final product, after the separation, is within the limits of the European Pharmacopoeia (>99.9%) up to 3 h after the EOB. Radiochemical separation up to a yield not lower than 75% was obtained using an automated purification module. The enriched material recovery efficiency resulted higher than 80–90%.
In summary, this approach provides clinically relevant amounts of 68Ga by cyclotron irradiation of a liquid target, as a competitive alternative to the current production through the 68Ge/68Ga generators.
ZR Resin and TK200 Resin
Malinconico, M., Asp, J., Lang, C., Boschi, F., Tieu, W., Kuan, K., Guidi, G., Takhar, P.:"68Ga and 45Ti production on a GE PETtrace cyclotron using the ALCEO solid target"
J Nucl Med May 1, 2018 vol. 59 no. supplement 1 664 , presentation available online.
Objectives: The ALCEO solid target system has been developed by Comecer for cyclotron production of 64Cu 89Zr, 123I and 124I. ALCEO Solid Target is composed by one irradiation unit (PTS), one dissolution/transfer unit (EDS/FDS) and one purification module (TADDEO PRF); all the units work automatically, avoiding any radiation exposures to operators. Many sites are already producing these radioisotopes with yields respectively of >2mCi/µAh (64Cu), >0.4mCi/µAh (89Zr and 123I), >0.1mCi/µAh (124I). The aim of this work was to expand the use of the ALCEO system to also produce 68Ga and 45Ti. Production and labelling results will be presented as well. Methods 68Zn was electroplated onto a target shuttle and irradiated (with a typical current from 10µA to 30µA) with 12.1 MeV protons to produce 68Ga. Irradiated target was dissolved in 10M HCl. The 68Ga was separated from the irradiated 68Zn using LN resin (TRISKEM), then labelled to PSMA and DOTATATE using an Eckert and Ziegler Modular-Lab eazy synthesis module. Natural scandium was irradiated with 12.1 MeV protons, with a typical current of 10µA to produce 45Ti. Irradiated target was dissolved by drop-by-drop 6M HCl. The 45Ti was separated from the irradiated scandium using ZR resin (TRISKEM), then labelled manually to DFO mesylate salt . Results 68Ga is produced with a saturation yield of 1330±590 MBq/µA (N=2), and was successfully labelled to PSMA and DOTATATE with 79.2% and 76.0% synthesis yields and 99.0% and 91.3% radiochemical purity respectively. 45Ti is produced with a saturation yield of 312 MBq/µA (N=1). It was not successfully labelled to PSMA and DOTATATE, however the labelling efficiency for DFO mesylate salt was 41%. Conclusions The Comecer ALCEO solid target system has been used successfully to produce 64Cu, 89Zr, 68Ga and 45Ti. The produced PET-isotopes have a very high radio-purity and chemical-purity and they can be used for radio-labeling processes. Future work includes optimisation of separation processes, and production of 203Pb and 44Sc.
ZR Resin and LN Resin
van Es, E.M., Russell, B.C., Ivanov, P. et al. :"The behaviour of 226Ra in high-volume environmental water samples on TK100 resin"
J Radioanal Nucl Chem (2017) 312: 105, https://doi.org/10.1007/s10967-017-5203-4
Accurate, low-level measurement of 226Ra in high volume water samples requires rapid pre-concentration and robust separation techniques prior to measurement in order to comply with discharge limits and drinking water regulations. This study characterises the behaviour of 226Ra and interfering elements on recently developed TK100 (Triskem International) extraction chromatography resin. Distribution coefficients over a range of acid concentrations are given, along with an optimised procedure that shows rapid pre-concentration and separation of 226Ra on TK100 resin is achievable for high volume (1 L) water samples without the need for sample pre-treatment.
Süfke, F., Lippold, J., Happel, S.: "Improved Separation of Pa from Th and U in Marine Sediments with TK400 Resin"
Anal. Chem., 2018, 90 (2), pp 1395–1401; DOI: 10.1021/acs.analchem.7b04723
Protactinium-231 is a radionuclide of broad interest in paleoceanography and paleoclimatology. This study describes an improved method for the purification and separation of Pa from marine sediment samples using the new TK400 resin by TrisKem International. The focus lies on the improvement of the separation of the abundant 232Th from the Pa fraction of the sample, which would reduce the peak tailing from 232Th on masses 231 and 233 during ICP-MS measurement. Furthermore, the reusability of TK400 has been tested. For this purpose, the conventional method using Dowex AG1X8 for the separation and purification of Pa has been compared to methods using the TK400 resin. A combination of a Dowex AG1X8 prior to a TK400 column has shown most convincing results. Based on our results we suggest a new efficient procedural method of analyzing 231Pa from marine sediment samples using TK400. Chemical Pa yields for a Dowex-TK400 combination are highest compared to the Dowex only method. Furthermore, the 232Th/231Pa ratio of the Pa-fractions has been reduced by 1 order of magnitude compared to conventional methods with Dowex AG1X8. Additionally, the reusability of TK400 resin up to nine times has been proven. The usage of TK400 is only limited in the presence of samples with a high matrix load (e.g., Fe). Therefore, matrix from sediment samples needs to be removed (here using Dowex resin) before samples are loaded onto TK400. We also report a series of concentration measurements from standard reference materials (UREM-11, NIST 2702), which have been used for 233Pa calibration.
Graves, S.A.: "Evaluation of a chloride-based 89Zr isolation strategy using a tributyl phosphate (TBP)-functionalized extraction resin"
Nuclear Medicine and Biology, Volumes 64–65, September–October 2018, Pages 1-7, https://doi.org/10.1016/j.nucmedbio.2018.06.003
The remarkable stability of the 89Zr-DOTA complex has been shown in recent literature. The formation of this complex appears to require 89Zr-chloride as the complexation precursor rather than the more conventional 89Zr-oxalate. In this work we present a method for the direct isolation of 89Zr-chloride from irradiated natY foils.
89Zr, 88Zr, and 88Y were prepared by 16 MeV proton irradiation of natY foils and used for batch-extraction based equilibrium coefficient measurements for TBP and UTEVA resin. Radionuclidically pure 89Zr was prepared by 14 MeV proton-irradiation of natY foils. These foils were dissolved in concentrated HCl, trapped on columns of TBP or UTEVA resin, and 89Zr-chloride was eluted in
Equilibrium coefficients for Y and Zr were similar between UTEVA and TBP resins across all HCl concentrations. Kd values of <10−1 mL/g were observed for Y across all HCl concentrations. Kd values of >103 mL/g were observed at HCl concentrations >9 M for Zr, falling to Kd values of
TBP-functionalized resin appears promising for the direct isolation of 89Zr-chloride from irradiated natY targets. Excellent 89Zr recovery efficiencies were obtained, and chemical purity was sufficient for proof-of-concept chelation studies.
Maoyi Luo et al.: "Sequential analyses of actinides in large-size soil and sediment samples with total sample dissolution"
Journal of Environmental Radioactivity, Volume 187, July 2018, Pages 73-80, https://doi.org/10.1016/j.jenvrad.2018.01.028
There is a growing demand for the determination of actinides in soil and sediment samples for environmental monitoring and tracing, radiological protection, and nuclear forensic reasons. A total sample dissolution method based on lithium metaborate fusion, followed by sequential column chromatography separation, was developed for simultaneous determination of Pu, Am and Cm isotopes in large-size environmental samples by alpha spectrometry and mass spectrometric techniques. The overall recoveries of both Pu and Am for the entire procedure were higher than 70% for large-size soil samples. The method was validated using 20 g of soil samples spiked with known amounts of 239Pu and 241Am as well as the certified reference materials IAEA-384 (Fangataufa Lagoon sediment) and IAEA-385 (Irish Sea sediment). All the measured results agreed very well with the expected values.
TEVA Resin and DGA, N Resin
Wang, Z., Lin, J., Li, S. et al. "Rapid method for accurate determination of actinides (U, Th, Pu and Am) in water samples for emergency response"
J Radioanal Nucl Chem (2018) 315: 103, https://doi.org/10.1007/s10967-017-5640-0
To rapidly assess the contamination of actinides in emergency water, a method was developed to simultaneously analyze U, Th, Pu and Am. The method consists of two steps: extraction chromatographic separation using UTEVA and DGA resins and isotopic determination of actinides by inductively coupled plasma mass spectrometry (ICPMS). The whole analytical procedure takes only 8 h and high chemical recoveries of actinides were obtained. The cross spectral interferences between actinides in ICPMS measurement were sufficiently removed. The accuracy was validated by analyzing IAEA-443 seawater sample. The low limits of detection of actinides allow this method to distinguish low level contamination.
UTEVA Resin and DGA resin
Marstren, T. et al. "Chromatographic separation of the theranostic radionuclide 111Ag from a proton irradiated thorium matrix"
Analytica Chimica Acta, Volume 998, 15 January 2018, Pages 75-82, https://doi.org/10.1016/j.aca.2017.10.020
Column chromatographic methods have been developed to separate no-carrier-added 111Ag from proton irradiated thorium targets and associated fission products as an ancillary process to an existing 225Ac separation design. Herein we report the separation of 111Ag both prior and subsequent to 225Ac recovery using CL resin, a solvent impregnated resin (SIR) that carries an organic solution of alkyl phosphine sulfides (R3P = S) and alkyl phosphine oxides (R3P = O). The recovery yield of 111Ag was 93 ± 9% with a radiochemical purity of 99.9% (prior) and 87 ± 9% with a radiochemical purity of 99.9% (subsequent to) 225Ac recovery. Both processes were successfully performed with insignificant impacts on 225Ac yields or quality. Measured equilibrium distribution coefficients for silver and ruthenium (a residual contaminant) on CL resin in hydrochloric and nitric acid media are reported, to the best of our knowledge, for the first time. Additionally, measured cross sections for the production of 111Ag and 110mAg for the 232Th(p,f)110m,111Ag reactions are reported within.
Alves, V.H. et al.: "Automated Purification of Radiometals Produced by Liquid Targets"
An automated process for the production and purification of radiometals produced by irradiating liquid targets in a medical cyclotron, using a commercially available module, has been developed. The method is suitable for the production and purification of radiometals such as 68Ga, 64Cu and 61Cu through irradiation of liquid targets and is important for producing high specific activity radioisotopes with a substantial reduction in processing time and cost when compared with the solid target approach. The “liquid target” process also eliminates the need for pre- and post-irradiation target preparation and simplifies the transfer of irradiated material from target to hotcell. A 68GaCl3 solution can be obtained in about 35 min with an average yield of 73.9 ± 6.7% in less than 10 mL of volume. 64CuCl2 solutions can be obtained with an average yield of 81.2 ± 7.8% in about 1 h of processing time. A dedicated single-use disposable kit is used on a commercial IBA Synthera® extension module.
Naperstkow, Z., Moore, K., Szames, D. et al.: "Production and standardization of an on-demand protactinium-233 tracer"
J Radioanal Nucl Chem (2018) 318: 703, https://doi.org/10.1007/s10967-018-6068-x
Protactinium-233 (233Pa) was generated by neutron activation of thorium and isolated by column chromatography using an octanol-impregnated resin. Absolute activity standardization was performed on 233Pa using three independent methods, the results of which agreed within their associated uncertainties. The standardized 233Pa was used to calibrate a secondary standard ionization chamber and high purity germanium detectors to enable a rapid and traceable method for the production and quantification of this radiotracer.
Papillo G. et al. :"New production cross sections for the theranostic radionuclide 67Cu"
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Volume 415, 15 January 2018, Pages 41-47, https://doi.org/10.1016/j.nimb.2017.10.022
The cross sections of the 68Zn(p,2p)67Cu, 68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga reactions were measured at the ARRONAX facility by using the 70 MeV cyclotron, with particular attention to the production of the theranostic radionuclide 67Cu. Enriched 68Zn material was electroplated on silver backing and exposed to a low-intensity proton beam by using the stacked-foils target method. Since 67Cu and 67Ga radionuclides have similar half-lives and same γ-lines (they both decay to 67Zn), a radiochemical process aimed at Cu/Ga separation was mandatory to avoid interferences in γ-spectrometry measurements. A simple chemical procedure having a high separation efficiency (>99%) was developed and monitored during each foil processing, thanks to the tracer isotopes 61Cu and 66Ga. Nuclear cross sections were measured in the energy range 35–70 MeV by using reference reactions recommended by the International Atomic Energy Agency (IAEA) to monitor beam flux. In comparison with literature data a general good agreement on the trend of the nuclear reactions was noted, especially with latest measurements, but slightly lower values were obtained in case of 67Cu. Experimental results of the 68Zn(p,2p)67Cu, 68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga reactions were also compared with the theoretical values estimated by using the software TALYS. The production yield of the theranostic radionuclide 67Cu was estimated considering the results obtained in this work.
Jerome, S.M. et al. "Isolation and purification of protactinium-231"
Appl Radiat Isot. 20:18 Apr;134:18-22, https://doi.org/10.1016/j.apradiso.2017.07.051
Protactinium-231 is one of the lesser known actinides, yet the measurement of this radionuclide is central to dating studies in both paleoclimate and nuclear forensics measurements; furthermore, it is important as the immediate parent nuclide of the 227Ac decay chain. In this paper, we present the preparatory work for an upcoming CCRI(II) supplementary comparison of this radionuclide. The material used in this work was of poorly known provenance, and it was necessary to carry out a chemical purification of this material prior to use. A new extraction chromatography resin, TK 400, which has been developed for the separation of 231Pa, was tested at NPL. The aims of the work were achieved; the recovery of 231Pa was ~85%, the decay products were recovered in good yield (~95%) and stable element impurities were removed.