AG50W-X8 Cation-exchange Resin Research Articles

Efficient production and purification of 32P radioisotope from sulfur by dry distillation: A practical approach with high radiochemical purity

The 32P radioisotope, with a half-life of 14.3 days and an energy level of 1.71 MeV, has diverse applications in medicine and research. Consequently, producing a carrier-free 32P radioisotope characterized by high radiochemical and radionuclide purity is imperative. Two primary methods for generating 32P radioisotopes exist: irradiating phosphorus through the nuclear reaction (n,γ) or irradiating sulfur through the nuclear reaction (n,p). Using sulfur as a target material provides several advantages. Besides the fact that the chemical element produced after irradiation (32P) differs from the irradiated element (32S), it also produces a32P radioisotope with a higher specific activity than using 31P as the target. The production of the radioisotope 32P from sulfur employs the dry distillation method, capitalizing on sulfur's easily sublimated nature. The volatility of sulfur when heated makes it easy to separate the resulting sulfur and radioisotope 32P without the need for additional reagents. This research aims to establish a practical method for producing the 32P radioisotope using the dry distillation technique. The dry distillation method utilizes a quartz ampoule containing a mixture of 32P and 35S radionuclides, a distillation tube wrapped with heating tape, and a condenser to collect the distilled sulfur. Sulfur, serving as the target material, undergoes irradiation in the reactor at the Central Irradiation Position (CIP) through the 32S(n,p)32P nuclear reaction with a fast neutron flux of 5.380 × 1013 n/cm2.sec. Separation is achieved through distillation at a temperature of 440 °C. The residual separation products are then dissolved in a 0.1 N HCl solution. The purification process involves using an AG50 WX8 cation exchange resin column, which is pre-conditioned with 0.1 N HCl. The resulting eluate contains the 32P radioisotope. The radiochemical purity of the 32P radioisotope is analyzed using thin-layer chromatography (TLC). In this analysis, a PEI Cellulose plate serves as the stationary phase, and a KH2PO4 solution acts as the mobile phase. This vacuum-free distillation method successfully separates the 32P radioisotope from sulfur, achieving a separation efficiency of 55.1 ± 9.9% (n = 7). The average activity produced after the purification process is 5.690E+10 Bq. Purifying the 32P radioisotope results in a radiochemical purity of 99.97% at Rf 0.7110, as orthophosphate, the radionuclide purity exceeds 99%.

Microwave Preparation of Geological Samples in UltraWAVE System for the Determination of Platinum Group Elements and Rhenium by Mass-Spectrometric Isotope Dilution

We report the first results of the application of UltraWAVE reactor-type microwave system for geological sample preparation (T = 250°C and P up to 80 bar) with a mixture of concentrated nitric and hydrochloric acids (3 : 1). Determination of the platinum group elements – Ru, Pd, Ir, Pt (PGE) and Re after acid digestion was carried out by isotope dilution using the high-resolution mass-spectrometer ELEMENT after chromatographic separation of analytes on an AG50Wx8 cation exchange resin. The monoisotopic rhodium was determined with 195Pt as an internal standard. The achieved detection limits were from 0.003 ng/g (Ir) to 0.09 ng/g (Pt). The correctness of the new procedure was confirmed by the analysis of geological reference samples—GP-13, UB-N, BHVO-2. The proposed procedure significantly accelerates and simplifies the preparation of geological samples for PGE and Re determination compared to the Carius tube technique.

Development of a 212Pb and 212Bi generator for homolog studies of flerovium and moscovium

A simple generator using AG 50Wx8 cation exchange resin has been developed for continual elution of 212Pb and 212Bi from the parent radionuclide 228Th, derived from 232U. Using 0.4 M HCl as an eluent will elute 212Bi while 212Pb is eluted with 2 M HCl. The generator has shown good reproducibility of elution bands. A generator set-up in 2013 has been in continual use over 4 years demonstrating that this generator system has a long and stable lifetime. The generator system presented here has served as a long-term method for attaining no-carrier-added 212Pb and 212Bi radionuclides for homolog studies of flerovium and moscovium.

Determination of Eu concentrations in coal, fly ash and sedimentary rocks using a cation exchange resin and inductively coupled plasma mass spectrometry (ICP-MS)

Europium (Eu) in coal, coal combustion residues (e.g., fly ash), and sedimentary rocks in coal-bearing sequences has attracted much attention in recent years mainly because of its world-wide demand and use as a geochemical indicator of geological setting for coal deposit studies. This paper presents a method for accurately measuring the concentration of Eu in coal, fly ash, and sedimentary rocks by quadrupole-based inductively coupled plasma mass spectrometry (ICP-MS), plus the use of closed-vessel microwave digestion and a cation exchange resin. To significantly diminish the inference of Ba-based polyatomic ions (137Ba16O, 136Ba17O, 135Ba18O, and 134Ba18OH) on 153Eu in coal, fly ash, and sedimentary rock samples, a Bio-Rad AG50W-x8 cation exchange resin was used to separate Ba from digested solutions of solid samples. The AG50W-x8 cation exchange resin can effectively separate the barium from digested solutions and thus could diminish the inference of Ba on Eu. The determination of Ba and Eu in the National Institute of Standards Technology (NIST) standard references of coal and fly ash samples showed that the use of the AG50W-x8 cation exchange resin combined with quadrupole-based ICP-MS analysis can provide a reliable method for the accurate determination of Eu concentrations in coal and coal-related samples. The method detection limits for Ba and Eu are 0.030 μg/l and 0.006 μg/l, respectively, and the determination coefficient of their calibration curves (linearity range 0–100 μg/l) is >0.9999. A Ba/Eu value of 1000 in the samples is proposed for judging the interference of Ba on Eu. If Ba/Eu > 1000, then Ba in coal, fly ash, and sedimentary rocks significantly interferes with Eu and this interference then needs to be considered when interpreting the analytical results and their significance.

Preparation of [48V]-VO2+ for biomedical studies

A new method for the highly efficient separation of48V for radiotracer experiments is presented. It is based on the proton irradiation of a high purity Ti plate which is dissolved in sulfuric acid to form Ti3+ and V4+. Both ions are quantitatively absorbed on AG50W-X8 cation exchange resin and are converted to the respective higher valence state by an on-column reaction with diluted nitric acid and hydrogen peroxide. The eluate containing V5+ is evaporated to dryness in presence of sulfuric acid and treated with ethanol to reduce [48V]-vanadate to [48V]-vanadyl for labeling experiments in pharmaceutical research.

Determination of trace elements in manganese metal and compounds by ion-exchange chromatography and atomic absorption spectrometry : part 2. Determination of Bi, Cd, In, Zn, Pb, Fe(III), Ga, Cu(II), Co and U(VI)

Traces of the specified elements are separated from 1 g of manganese (II), using a 30- g column of AG50W-X8 cation-exchange resin and mixtures of hydrochloric acid and acetone as eluents. The trace elements are separated into three groups and are determined by atomic absorption spectrometry, except uranium for which spectrophotometry is used. Recoveries for 10 μg amounts (20 μg for gallium) vary between 94% (for gallium) and 103% (for uranium). A combined elution curve, results for the analysis of synthetic mixtures and for the determination of ten trace elements in samples of manganese metal, chloride and dioxide are presented.

Determination of trace elements in manganese metal and compounds by ion-exchange chromatography and atomic absorption spectrometry : Part 1. Determination of Li, Na, K, Be, Ti(IV), Mg, Ni, Ca and Al

Traces of the specified elements can be separated from 1-g amounts of manganese(II), using a 20-g column of AG50W-X8 cation-exchange resin. The trace elements are separated into four groups and are determined by atomic absorption spectrometry, except titanium, which is determined spectrophotometrically. With the exception of sodium, recoveries for 10 μg amounts vary between 94% (for nickel) and 101% (for magnesium). Relevant elution curves, results for the analysis of synthetic mixtures and for the determination of eight trace elements in samples of manganese metal, manganese chloride and manganese dioxide are presented.

Quantitative separation of lanthanides and scandium from barium, strontium and other elements by cation-exchange chromatography in nitric acid

The lanthanides plus yttrium and scandium are separated from Ba, Sr, Ca, Mg, Pb(II), Bi(III), Zn, Mn(II) and U(VI) by eluting these elements with 2.0 M nitric acid from a column of AG50W-X8 cation exchange resin (200-400 mesh). The lanthanides are retained and can then be eluted with 4 M nitric or hydrochloric acid. Separations are quantitative and applicable to microgram and millimolar amounts of the lanthanides and the other elements. Elements such as Cu(II), Co(II), Ni(II), Cd. Hg(II), T1(I). Ag, Be, Ti(IV) and the alkali metals should accompany barium quantitatively according to their known distribution coefficients. Relevant elution curves and results of analysis of synthetic mixtures are presented.

Selective separation of indium from zinc, lead, gallium and many other elements by cation-exchange chromatography in hydrohalic acid—acetone medium

Indium can be separated from Zn, Pb(II), Ga, Ca, Be, Mg, Ti(IV), Mn(II), Fe(III), Al, U(VI), Na, Ni(II) and Co(II) by selective elution with 0·50 M hydrochloric acid in 30% aqueous acetone from a column of AG50W-X8 cation-exchange resin, all the other elements being retained by the column. Lithium is included in the elements retained by the column when 0·35 M hydrochloric acid in 45% aqueous acetone is used for eluting indium, but the elution of indium is slightly retarded. Ba, Sr, Zr, Hf, Th, Sc, Y, La and the lanthanides, Rb and Cs should also be retained according to their distribution coefficients. Cd, Bi(III), Au(III), Pt(IV), Pd(II), Rh(III), Mo(VI) and W(VI) can be eluted with 0·20 M hydrobromic acid in 50% aqueous acetone before the elution of indium, and Ir(III), Ir(IV), As(III), As(V), Se(IV), Tl(III), Hg(II), Ge(IV), Sb(III) and Sb(V), though not investigated in detail, should accompany these elements. Relevant distribution coefficients and elution curves and results for analyses of synthetic mixtures of indium with other elements are presented.

Cation-exchange separation of strontium from manganese and other elements in citrate media

Mn(IT) can be eluted quantitatively with 0.067 M ammonium citrate at pH 7.0 or 7.5 from a column of AG50W-X8 cationexchange resin (200-400 mesh), and separated from Sr which is retained. Mg, Ca, Cu(II), Zn and Co(II) accompany Mn(II). From citric acid solutions up to 1 M (20%) and from 5 % citric acid solution at pH 2.2 both Mn(II) and Sr are retained very strongly. This is in agreement with some previous work but disagrees with a recent statement by others that 5 % citric acid at pH 2.2 is an effective eluting agent for Sr.

Accurate determination of traces of sodium and potassium in rocks by ion exchange followed by atomic absorption spectroscopy

Sodium and potassium (5–1000 p.p.m.) in rocks such as peridotites and dunites can be determined accurately by ion-exchange separation followed by atomic absorption spectrophotometry. The samples are decomposed in sulphuric, hydrochloric and hydrofluoric acid mixtures, and after removal of hydrofluoric acid the cations are absorbed on a 90-ml column of AG50W-X8 cation-exchange resin. Vanadium and other anion-forming elements are eluted with 0.01 M nitric acid containing hydrogen peroxide. Then the alkali metals are eluted with 0.50 M nitric acid, while Mg, Mn, Ca, Ti, Al, Fe and other multivalent elements are retained by the column. The eluate fractions containing the respective alkali metals are measured directly by atomic absorption spectrophotometry against standards in 0.50 M nitric acid. Relevant elution curves, results for synthetic mixtures and for three international rock standards are presented and discussed.

Comparative distribution coefficients and cation-exchange behaviour of the alkaline earth elements with various complexing agents

Equilibrium distribution coefficients are presented for the alkaline earth metals Be(II), Mg(II), Ca(II), Sr(II) and Ba(II) with the complexing agents acetate, formate, lactate, citrate, tartrate, α-hydroxyisobutyrate, malonate, malate, acetylacetonate, EDTA, EGTA and DCTA, and the AG50W-X8 cation-exchange resin. Coefficients in HCl, HNO 3, HClO 4 and NH 4Cl are included for the sake of completeness. The merits of the various complexing agents for the separation of adjacent element pairs are discussed and experimental elution curves are presented for selected separations. Separation factors for adjacent elements are calculated at eluting agent concentrations corresponding to a distribution coefficient of 10 for the less strongly absorbed element and are presented together with the eluting agent concentrations to form a basis for comparison.