Separation Column Research Articles

The application of selective leaching and complex anion exchange in a novel aqueous process to produce pure indium from waste liquid crystal display panels

By studying the leaching kinetics of indium from waste liquid crystal displays (LCD), it was pointed out, that recoveries of > 90 % are possible with 0.5 M HCl at 80 °C or 2 M HCl at 55 °C. The anion-exchange sorption of indium was found practically negligible from sulphate solutions, however, in chloride solutions of 2 mol/dm3 HCl (or NaCl) indium was moderately sorbed (log D = 0.83), and a further increase of the distribution coefficient (log D = 1.1) was found until 6 mol/dm3 Cl- ion concentration. Based on the determined activation energies, at low (< 1 M) HCl concentrations, the process is controlled by the formation of the complex species, while above, diffusion and transport processes are more important. The devised chromatographic separation in an anion-exchange column was able to eliminate virtually all the practical impurities. After loading the leachate of 5 mol/dm3 chloride ion concentration, the non-sorbed alkali, alkaline earth and some transition metals can be removed by rinsing the resin bed with a solution of 2 mol/dm3 chloride ion concentration. Indium can be eluted by reducing the chloride ion concentration in the influent to 0.25 mol/dm3. The still retained elements (Zn, Sn, Bi) can be removed with 1 M NaOH solution. The pure solution was used to electrowon indium metal, which was analysed by SEM-EDS and - after dissolution – with ICP – OES. The purity of the metallic indium product was found to be 99.9997 %.

Determination of 93Mo in Radioactive Samples of Sulfuric Acid Media from Nuclear Facilities.

93Mo is an important radionuclide in view of radioactive waste repository because of its long half-life and high mobility in the environment. 93Mo decays by electron capture without any measurable gamma ray emission. The concentration of 93Mo in most of the radioactive waste is many orders of magnitude lower than the major activation product radionuclides, which makes the accurate determination of 93Mo a big challenge. A new analytical method for the determination of 93Mo in sulfuric acid media from nuclear power reactor was developed. 93Mo was separated from most of the radionuclides by cation exchange chromatography followed by the removal of sulfate by CaSO4 precipitation. A further purification of 93Mo, especially from anion species of 51Cr and 125Sb, was achieved by anion exchange chromatography and a short alumina column separation. The chemical yield of 93Mo in the entire separation procedure reached about 75%, and the decontamination factors for all potential interfering radionuclides were 1.5 × 106-1.6 × 108. The purified 93Mo was measured by liquid scintillation counting through counting its low-energy Auger electrons. A detection limit of 2 mBq/g for 93Mo in 50 g sample was achieved by this method, which enables the quantitative determination of 93Mo in most of the radioactive samples in the decommissioning waste and coolant water of nuclear power reactors. The developed method has been successfully applied to determine 93Mo in coolant water of nuclear power reactors, providing a robust analytical approach of 93Mo for the radiological characterization of radioactive wastes.

Optimization of performance parameters and investigation of the heavy-medium separation column for the separation of 3-13mm steam coal

ABSTRACT To effectively separate 3–13 mm steam coal, new separation equipment which was a heavy-medium separation column was designed and tested in this study. Particles were measured to analyze the changes in the axial medium force of particles in the medium by employing the force measuring system. The influence of the medium flow rate (q), medium density (ρ), separation column height (h), and feed volume (g) on the separation effect was investigated by using the control variable method to establish the optimum separation condition. Under the optimum separation condition, the yield and the ash content of the clean coal were 74.05% and 16.18%, respectively. Based on the single factor study, the Box-Behnken response surface methodology (BBRSM) was used to investigate the influence of each interaction factor on the separation effect. The significance of each factor on the quantitative efficiency was in the order of ρ > q > h. Through the regression analysis, the mathematical model for the relationship between the quantitative efficiency and the separation parameters was established. The predicted quantitative efficiency and experimental quantitative efficiency were 87.88% and 89.32%, respectively. The difference between them was small, verifying the high accuracy and reliability of the prediction results of the regression equation model.

Control and Simulation of A 13C Isotope Separation Process

This paper is presenting a control solution for the concentration of the 13C isotope, both at the output and inside of the separation column; the proposed solutions are a relay and a PID controller. The 13C isotope results after a distributed parameter process, specifically the chemical exchange process of the carbon dioxide and carbamate. The analytical solution that was determined in order to model the described process is simulated. The evolution of the proposed solution depends on two parameters: the position in the column height and the time. The reference model is simulated in order to reach to the desired concentration using an acceptable flow of solution. The tuning method for the PID controller is Ziegler-Nichols, based on the bipositional relay. The advantage obtained during this control process consists of the possibility of reaching the desired concentration of the 13C isotope at any point of height inside the separation column.

A fast, single column high-performance anion exchange chromatography with pulsed amperometric detection method for the determination of saccharides in atmospheric aerosol samples.

Saccharides, especially anhydro sugars present in atmospheric aerosols, can be used as tracers to track sources of atmospheric aerosols. High-performance anion-exchange chromatography with pulsed amperometric detection is a commonly used technique for determining these saccharides, but the reported methods suffer from three drawbacks. First, to achieve separation of the complete set of atmospheric saccharides, run times are very long, typically longer than 60 minutes. Second, some methods require two columns to achieve the desired separation. Finally, in an era when electrolytic eluent preparation allows for excellent precision and accuracy, these methods require manually prepared eluents, which can lead to separation inconsistency for closely eluting analytes. These drawbacks make existing methods difficult to automate. To address this issue, we developed a fast method that uses only a single column for separation and electrolytically generated eluent that resolves 12 key atmospheric aerosol saccharides in 20 minutes. The resolved saccharides include anhydro sugars (levoglucosan, galactosan, and mannosan), sugar alcohols (erythritol, xylitol, and mannitol), and mono-/disaccharides (arabinose, galactose, glucose, mannose, fructose, and sucrose). To our knowledge, this report is the first instance of achieving such a significant reduction in run time with good resolution for this set of saccharides.

Multi‐objective optimization and dynamic control of heat exchanger network for heat pump distillation of acetic acid/acetic anhydride binary system

AbstractIn this paper, the heat pump distillation coupled heat exchange network system (MVRHP‐HEN) for acetic acid/acetic anhydride separation is optimized with the minimum total annual cost (TAC) and CO2emissions as objective functions, meanwhile, the optimized process is simulated dynamically. Firstly, we proposed two optimization schemes: (a) the single objective and multi‐objective optimizations of the MVRHP system over the acetic acid separation column are firstly carried out and then constructed the heat exchange network, namely, MVRHP‐HEN‐1; (b) the heat exchange network is first constructed and then the single objective and multi‐objective optimization of MVRHP‐HEN is carried out, that is, MVRHP‐HEN‐2. The results show that MVRHP‐HEN‐2 obtains lower TAC and CO2emissions compared with MVRHP‐HEN and MVRHP‐HEN‐1 and has better economic and environmental benefits. Then, the two‐point temperature control structure is built for the dynamic simulation of the optimized separation process. The results show that the proposed control structure has a strong anti‐interference ability. The research is expected to provide guidance for the development and design of advanced heat pump distillation technology.

Development of N,N,N′,N′-tetra-2-ethylhexyl-thiodiglycolamide silica-based adsorbent to separate useful metals from simulated high-level liquid waste

A novel silica-based adsorbent was synthesized by impregnating macroporous silica polymer composite (SiO2-P) particles with a mixture of N,N,N',N'-tetra-2-ethylhexyl-thiodiglycolamide (TEHTDGA) and tri-n-octylamine (TOA). Then, the possibility of separating Pd(II) and other metal ions from simulated high-level liquid waste (HLLW) using the newly synthesized adsorbent (TEHTDGA+TOA)/SiO2-P was evaluated based on various adsorption characteristics obtained via batch-adsorption experiments, such as the HNO3 concentration, contact time, reaction temperature, adsorption isotherm, and chemical stability of the adsorbent. Furthermore, column separation experiments were performed based on the characteristics obtained from the batch-adsorption experiment, and the possibility of simultaneous separation of multiple metal ions was examined. The experimental results revealed that (TEHTDGA+TOA)/SiO2-P performs well in the separation of multiple metal ions from simulated HLLW.

Regeneration of Used Lube Oil by using Solvent Extraction Method

Regenerated or recycle of oil is economical process and reduce the environmental pollution produce from the used lube oil. Regenerated of used oil with solvent extraction shows the yield up to 90 % which is more than the oil regenerated from the different acid. In the solvent extraction we need separate column for solvent recovery. The major benefit of solvent extraction process gives higher yield and high quality product compares with acid treatment process and also reduce the sludge generation problem that produce by acid method. That will be reduce the degree and nature of contamination, environmental/health risks associated with disposal. With help of Activated charcoal/alumina or silica gel can removes the color and various impurities presents in the recycled used oil by using different acids. The major drawback to the acid/clay method is difficulty of removal of clay sludge. MEK are 62%, 68% and 72% at feed to solvent ration 1:2, 1:4 and 1:6 settling time 24 hr., extraction 30-40 mins at temperature of 35-45 OC. As per analysis the optimum feed to solvent ration will be 1:4 in which yield of oil and its properties are satisfactory for further use of oil. As per analysis with MEK solvent regenerated oil gives highest yield or recovery of lube oil from waste oil. As per analysis the optimum feed to solvent ration will be 1:4 in which yield of oil and its properties are satisfactory for further use of oil. Solvent extraction process cost reducing, less sludge producing and high yield process. All there solvents have better yield and high recoverability by simple distillation process. By experimental analysis it’s clear that the solvent extraction process for regeneration of lube oil is easy, simple, cost effective and low sludge producing. Additionally use of alumina or silica gel are beneficial for removal of impurities and color from regenerated oil.

A rapid method of simultaneous chromatographic purification of Li and Mg for isotopic analyses using MC-ICP-MS

Lithium (Li) and Magnesium (Mg) isotopes have been widely used as valuable tracers to study geological processes. In general, several column separation procedures have been used to separate Li and Mg. In this study, we present an optimized protocol for the rapid and simultaneous purification of Li and Mg, which significantly reduces the separation time, required reagent volume, and procedural blanks compared to previous methods. Samples with small amounts of Li (generally 5 ng Li yielding Mg masses of 1–1200 μg) were separated, with the corresponding yields of Li and Mg being nearly 100%. Lithium and Mg isotope analyses were performed using an MC-ICP-MS (Thermo Scientific NEPTUNE Plus) and only <0.2 ng Li and <150 ng Mg were consumed for each analysis. Matrix-doping experiments reveal that the matrix effect is negligible for the determination of Li and Mg isotopes from a wide array of geological samples using our protocol. The robustness of the protocol has been validated by replicated analyses of standard solutions and geological standards, which yield long-term external 2σ precision better than ±0.6‰ for δ7Li and ±0.08‰ for δ26Mg. Lithium and Mg isotopic ratios of all reference materials measured in this study agreed well with previous data within uncertainties. The method developed in this study allows for the rapid and high-purity separation of Li and Mg and subsequent high-precision isotopic analyses of these elements.

Establishment and validation of a UPLC-MS/MS bioassay for the quantification of infigratinib in rat plasma

Infigratinib (INF) is a fibroblast growth factor receptor (FGFR)-specific tyrosine kinase inhibitor for the therapy of advanced cholangiocarcinoma. However, CYP3A4 polymorphisms and CYP3A4 inducers or inhibitors might affect the pharmacokinetics of INF. Clinical evaluation of drug-drug interactions and adverse effects in these patients was necessary with reference to INF levels in vivo . The presently conducted study optimized a reproducible and rapid ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) analytic technique, which was validated and applied to determine INF concentrations in Sprague-Dawley (SD) rat plasma and pharmacokinetic studies. Protein was precipitated by adding acetonitrile to plasma samples, followed by gradient elution on a Waters Acquity UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) for complete chromatographic separation of the analyte and derazantinib (used as internal standard, IS). A gradient elution of 0.1% formic acid aqueous solution and acetonitrile at a flow rate of 0.30 mL/min was applied as the mobile phase for this analysis. The ion transitions of INF and IS were m / z 599.88 → 313.10 and m / z 468.96 → 382.00 during UPLC-MS/MS detection, respectively, by multiple reaction monitoring (MRM). The methodological validation demonstrated that INF presented high linearity over the concentration of 2–600 ng/mL. The lower limit of quantification (LLOQ) for this experiment was 2 ng/mL, of which the precisions and accuracies were within the permissible levels. Inter-day and intra-day precisions were demonstrated to be within reasonable limits, which were within 15%, and the accuracies were determined to be between 2.2% and 11.4%. Moreover, the values of recovery, stability and matrix effect of INF were within the limits of acceptability. The pharmacokinetics of INF in SD rats was investigated by gavage administration of 10 mg/kg INF, followed by the application of the developed UPLC-MS/MS analytical method to detect the content in plasma and derive the main pharmacokinetic parameters.

Preparation of aurum chloride complex and its use for industrial acetylene hydration catalyst process

The use of a modern homogeneous metal complex catalyst for the hydration of acetylenes is being investigated. The process is relevant both for the industry of basic organic synthesis and for the perfume industry. The analysis of existing processes used in industry for the production of acetaldehyde was carried out. Significant shortcomings of existing processes are revealed: low environmental friendliness and high energy consumption. To solve this problem, the reaction of hydration of an acetylene compound was studied using a modern homogeneous catalyst based on gold, which is not toxic. The study was conducted by selecting aliquots during the reaction. Using the 1H NMR spectroscopy method, the conversion values of phenylacetylene were calculated for the time values corresponding to the moments of aliquot sampling. The reaction order with respect to phenylacetylene was calculated and the reaction constant under the reaction conditions was calculated. When reacting in the presence of the proposed catalyst, a conversion of phenylacetylene of 86.96 % is achieved in 3 hours. The data obtained provide grounds for carrying out the process of catalytic hydration of acetylenes, namely phenylacetylene, with the production of acetophenone, which is important for use in the perfume industry. The data obtained can be applied to the process of hydration of acetylene with the formation of acetaldehyde, which is widely used in the industry of basic organic synthesis. For the process of catalytic hydration of acetylene compounds, a hardware design is proposed, a gas-liquid reactor with a changing hydrodynamic situation, which, together with the product separation column, is combined into a single installation. Using an optimized method, a catalyst based on gold chloride was synthesized from a gold alloy.

Surface-Charged Hybrid Monolithic Column for MS-Compatible Peptide Separation with High Peak Capacity and Its Application in Proteomic Analysis.

For bottom-up proteomics, peptide separation with high peak capacity under MS-compatible conditions is of vital significance to increase proteome coverage. Herein, a surface-charged ethane-bridged hybrid monolithic column was prepared based on the efficient ring-opening reaction of N-methyl-aza-2,2,4-trimethyl-silacyclopentane after C18-functionalization. The existence of secondary amino groups on the surface was beneficial to reduce the secondary interactions of silanol groups and increase peak capacity for peptide separation with MS-compatible mobile phases (e.g., using 0.1% FA as the mobile phase modifier). Such columns offered a 4-fold increase in peak capacity compared with ethane-bridged hybrid monolithic columns without surface charge modification. By a 100 cm length surface-charged ethane-bridged hybrid capillary column, high peak capacity of 700 was achieved within a 240 min gradient for the separation of Hela tryptic peptides with 0.1% FA-containing mobile phases, under the low backpressure of ∼200 bar. On average, 44493 ± 459 peptides corresponding to 5148 ± 47 proteins were identified from 750 ng Hela tryptic digests. Finally, the surface-charged ethane-bridged hybrid monolithic column was successfully applied in the quantitative proteomic analysis of dopaminergic neuron death model of N-methyl-4-phenylpyridinium iodide induced SH-SY5Y cells. These results demonstrated great promise of such surface-charged ethane-bridged hybrid monolithic columns for bottom-up proteomic analysis in complex samples.

Hierarchical covalent organic frameworks-modified diatomite for efficient separation of bisphenol A from water in a convenient column mode

To optimize the highly stacked, lamellar covalent organic frameworks (COF) with more easily accessible micropores for molecular separations, a facile and economical strategy, using the naturally available diatomite (Dt) as a substrate, is proposed to fabricate hierarchical Dt@COF hybrids through an in-situ solvothermal method to grow a uniform COF shell on Dt. This strategy not only enormously enhances the adsorption capacity of diatomite through introducing abundant micropores, but also endows the grown COFs with highly accessible adsorption sites for molecular adsorption owing to the ultrathin COFs shell and the intrinsic porosity of the diatomite matrix. The maximum adsorption capacity of COFs from Dt@COF-0.04 is 686 mg g−1 toward bisphenol A (BPA), outperforming the bulk COFs adsorbent (∼381 mg g−1). Significantly, in a more convenient column separation mode, the equilibrium adsorption amount of Dt@COF-0.04 is ∼3 times greater than that of the COF/Dt mixture. It is found that the thin COFs shell and the intrinsic microchannels of diatomite nanoplates synergistically facilitate the diffusion of water molecules and pollutants, leading to the outstanding performance of Dt@COF adsorbents. The results indicate that the hierarchical Dt@COF hybrids have great application potential in the separation of organic pollutants from water for environmental remediation.

Study of the separation ability differences of three covalent organic frameworks as coated materials in capillary electrochromatography

Covalent organic frameworks (COFs) have great potential applications in chromatographic separation. So it is crucial to understand the relationship between the separation ability of COFs and their structures. Here we report a strategy to evaluate the separation ability of three 2D COFs and explore the relationship between separation ability and their molecular structures. The three 2D COFs (COF-LZU1, COF-42 and COF-LZU8) have one same building unit 1,3,5-triformylbenzene, while varied from the conjugated linking units and functional side-chains. They were used to construct coated capillary column for capillary electrochromatographic separation of same groups of phthalates. They exhibited different separation efficiencies. COF-42 and COF-LZU8 coated capillary columns provided good signal resolutions and high column efficiencies with high theoretical plate numbers. It is demonstrated that COFs with hydrazone unit and longer side-chains provided higher selectivity and resolutions for the phthalates separation. Molecular simulations and DFT calculations were further proceeded to explore the deep reason why the three COFs coated CEC displayed different separation ability based on the host−guest interactions on molecular level. This work highlights a new opportunity to select or design functional COFs and improve their efficiency in chromatographic separation based on host−guest chemistry.

A study of diabatic distillation in a column with a low pressure drop

This paper examines diabatic columns with a new type of tray. The design provides effective liquid reflux flow in each column tray and a low pressure drop. The contact devices comprise a stack of multi-diameter plates with raised edges. The vertical tubes of the dephlegmator integrated into the column centre pass across all plates, and are used for heat removal. Vapors of the ascending mixture partially condense onto the plate surfaces and the dephlegmator, resulting in vapor enrichment. The liquid flow down the column forms a thin layer on the surfaces of the middle and bottom plates. When the condensate drops onto the smaller-diameter top tray, it partially evaporates, is then mixed with the liquid flow on the underlying plates, and partially evaporates again. An algorithm calculation of distillation parameters for a diabatic column, with a known reflux flow rate, vapor velocity and heat transfer coefficient, is proposed and approbated. The column separation efficiency is assessed depending on the temperature and cooling-water flow rate in the dephlegmator pipe. Several approaches for enhancing the heat transfer intensity in the column dephlegmator pipe were analysed. Several heat removal methods, including liquid film flow cooling of the inner dephlegmator pipe surface, were examined. Experimental tests were carried out using an ethanol-water binary mixture and a raw spirit complex mixture. Comparison of the characteristics of the new diabatic unit and a packed column with a spiral prismatic packing showed that the plate column with the same separation efficiency has a lower pressure drop and metal consumption. The results encourage further research on this new diabatic column design.

Development of Narrow-Bore C18 Column for Fast Separation of Peptides and Proteins in High-Performance Liquid Chromatography.

Separation with high efficiency and good resolution is constantly in demand in the pharmaceutical industry. The fast and efficient separation of complex samples such as peptides and proteins is a challenging task. To achieve high efficiency with good resolution, chromatographers are moving towards small particles packed into narrow-bore columns. Silica monolith particles (sub-2 µm) were derivatized with chlorodimethyl octadecyl silane (C18) and packed into stainless steel columns (100 mm × 1.8 mm i.d) by a slurry-packing method. The developed columns were used for the separation of peptides and proteins. A separation efficiency (N) of 40,000 plates/column (400,000 plates/m) was achieved for the mixture of five peptides. Similarly, the fast separation of the peptides was carried out using a high flow rate, and the separation of the five peptides was achieved in one minute with high efficiency (N ≅ 240,000 plates/m). The limit of detection (DL) and the limit of quantification (QL) for each analyte were determined by developing a linear regression curve with relatively very low concentrations of the target compound. The average values of the QL for the peptide and proteins were 0.55 ng and 0.48 ng, respectively, using short C18 column (1.8 mm × 100 mm) UV (at 214 nm). The fast analysis of peptides and proteins with such high efficiency and good resolution has not been reported in the literature yet. Owing to high efficiency, these home-made columns could be used as an alternative to the expensive commercial columns for peptide and protein separation.

Determination of valsartan in its pharmaceutical preparations using high-performance liquid chromatography technique

High-performance liquid chromatography technique was used to estimate valsartan in its pure form and in some pharmaceutical preparations. It was found through the results obtained that the proposed method is sensitive and accurate, and the estimation was done in a short time. In this work, a No L1, 150mm separation column was used to separate the components as they were type The UV spectrometer was used as a wavelength of 239 nm, the column temperature was 40°C, and the mobile phase consisted of 50:50 (acetonitrile: methanol: drops of triethylamine, pH = 2.4) at a flow rate of 1 ml/min. Through what was reached, we find that the method is sensitive, accurate and compatible, as the percentage recovery reached (100.63-103.35), and the linearity was (40-120 mcg/ml) for valsartan. The method was applied to a number of pharmaceutical preparations available in the local market, and the method was successful in the quantitative estimation of valsartan.

Use of high-performance liquid chromatography technique for the simultaneous determination of amlodipine and valsartan

This technique was used in the estimation of amlodipine and valsartan simultaneously. The method was sensitive and accurate, and the estimation was done in a short time. In this work, a separation column of type L1, 150 mm was used to separate and sold. The group also found the ultraviolet spectrophotometer that used a wavelength of 239 nm, the temperature of the column was 40 degrees Celsius, and the mobile phase, consisting of 50:50 (acetonitrile: methanol: drops of triethylamine, pH = 2.4) was long. Through what was reached, we find that the method is sensitive, accurate and medium in size (101.43-99.13) and (100.17-99.53), and linear punches (6-14 mcg/ml) and (48-112 mcg/ml) for the two drugs, respectively. The method was applied to a number of pharmaceutical preparations available in the local market, successful in the real-time quantification of amlodipine and valsartan, respectively.

An analytical quality by design approach towards a simple and novel HPLC-UV method for quantification of the antifibrotic peptide N-acetyl-seryl-aspartyl-lysyl-proline

N-acetyl-seryl-aspartyl-lysyl proline (Ac-SDKP) is a tetrapeptide possessing anti-fibrotic, angiogenic, anti-inflammatory, anti-apoptotic, and immunomodulatory properties. Currently, the main method to quantify the peptide is liquid chromatography-tandem mass spectrometry (LC-MS/MS) and enzyme-linked immunosorbent assay (ELISA), both of which are labour intensive and require expensive equipment and consumables. Furthermore, these techniques are generally utilised to detect very low or trace concentrations, such as in biological samples. The use of high concentrations of analyte might overload the extraction column or the separation column in LC-MS/MS or the ELISA plates, so the response could be a non-linear relationship at high analyte concentrations. Thus, they are not ideal for formulation development where detection of dose-equivalent concentrations is typically required. Therefore, a cost-effective, simple, and accurate quantification method for the peptide at a higher concentration needs to be developed. In this study, a simple and novel HPLC-UV method is proposed and validated using an Analytical Quality by Design (AQbD) approach. The method is first screened and optimised using chromatographic responses including capacity factor, resolution, tailing factor, and theoretical plate counts, fulfilling the International Council for Harmonisation (ICH) Q2 (R1) guidelines. The resultant optimised chromatography conditions utilised 10 mM phosphate buffer at pH 2.5 and acetonitrile as mobile phases, starting at 3% (v/v) acetonitrile and 97% (v/v) buffer and increasing to 9.7% (v/v) acetonitrile and 90.3% (v/v) buffer over 15 min at a flow rate of 1 mL/min at the column temperature of 25 °C. The injection volume is set at 10 μL and the VWD detector wavelength is 220 nm. The method established is suitable for detecting the peptide at a relatively high concentration, with a quantifiable range from 7.8 μg/mL to 2.0 mg/mL. In addition, the use of a relatively simple HPLC-UV approach could significantly reduce costs and allow easier access to quantify the peptide concentration. A limitation of this method is lower sensitivity compared with using LC-MS/MS and ELISA methods but running costs are lower and the methodology is simpler. The method is capable to quantify the peptide in various tested matrix solutions, with successful quantitation of the peptide in samples obtained from in vitro drug release study in PBS and from a chitosan-TPP nanogels formulation. Therefore, the method developed here offers a complementary approach to the existing quantification methods, quantifying this peptide at increased concentrations in simple to intermediately complex matrix solutions, such as HBSS, DMEM and FluoroBrite cell culture media.

Development of Chemical Procedures for Isotope Harvesting: Separation of Trace Hafnium from Tungsten

ABSTRACT The separation of trace hafnium from bulk tungsten alloys is of interest for isotope harvesting at the National Superconducting Cyclotron Laboratory and the Facility for Rare Ion Beams because 172Hf, the parent of 172Lu, accumulates in tungsten alloy beam blockers at these facilities. In this work, a procedure for the separation of trace hafnium from a bulk tungsten alloy (454 g) was established using tracer isotopes (175Hf, 88Zr, 173Lu, and 88Y). The procedure employed dissolution in an HF–HNO3 solution followed by a calcium fluoride precipitation, and then extraction chromatography was used for more selective separation steps. Two stages of column separations using LN resin (HDEHP based) and TRU resin (CMPO based) were performed. Gamma-ray spectroscopy and mass spectrometry were used to analyze the final hafnium sample and follow the steps in the chemical processing. The final recovery of hafnium was high (90 ± 8)%, and the mass of tungsten and other transition metals was reduced to near background levels (as determined by ICP-MS of the blank acid solutions). Zirconium follows hafnium quantitatively in this procedure; there was no detectable 173Lu in the final hafnium sample.