99Mo/99mTc radioisotope generator based on adsorption of 99Mo (VI) on cerium (IV) molybdate column matrix

2018 ◽  
Vol 106 (12) ◽  
pp. 991-999 ◽  
Author(s):  
Hassan El-Said ◽  
Hala Ramadan ◽  
Mahmoud Abbas ◽  
Maher El-Hashash
Keyword(s):  
Sorption Capacity ◽  
Flow Rate ◽  
Radiochemical Purity ◽  
Specific Activity ◽  
Sorption Behavior ◽  
Nacl Solution ◽  
High Chemical ◽  
Column Matrix ◽  
Chromatographic Columns ◽  
Nitrate Solutions

Abstract Based on neutron activated 99Mo, a procedure for preparation of 99Mo/99mTc radioisotope generator was developed. Batch equilibration method was used to investigate the sorption behavior of Mo (VI) (10−4 M) in chloride and nitrate solutions on cerium (IV) molybdate gel matrix using 99Mo radiotracer. The breakthrough sorption capacity of cerium molybdate gel matrix for 99Mo (VI) (3×10−2 M) were found to be 0.54 mmol/g of the sorbent [1 g column (0.6 cm i.d.)]. Elution performance of the generated 99mTc from cerium molybdate-99Mo chromatographic column was investigated as a function of inside diameter of the column, amount of the bed matrix and flow rate of the eluent. Based on the obtained results, 99Mo/99mTc radioisotope generator was prepared based on adsorption of neutron activated 99Mo (VI) of low specific activity onto chromatographic columns packed with 5 g cerium molybdate gel matrix. The radioactivity of 99mTc is periodically eluted with 10 mL 0.9% NaCl solution at a flow rate of 1 mL/min. Elution yield of 78±5% was obtained with high chemical, radionuclidic (99Mo breakthrough 1×10−3±0.3×10−3%) and radiochemical purity (97±2%).

scholarly journals Effect of Fluid Flow on the Corrosion Performance of as-Cast and Heat-Treated Nickel Aluminum Bronze Alloy (UNS C95800) in Saline Solution

2021 ◽  
Vol 2 (1) ◽  
pp. 61-77
Author(s):  
Hamid Reza Jafari ◽  
Ali Davoodi ◽  
Saman Hosseinpour
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Flow Rate ◽  
Solution Temperature ◽  
Aluminum Bronze ◽  
Nickel Aluminum ◽  
Nacl Solution ◽  
Flow Conditions ◽  
Heat Treated ◽  
Nickel Aluminum Bronze

In this work, the corrosion behavior and surface reactivity of as-cast and heat-treated nickel aluminum bronze casting alloy (UNS C95800) in 3.5 wt% NaCl solution is investigated under stagnant and flow conditions. Increasing flow rate conditions are simulated using a rotating disk electrode from 0 to 9000 revolutions per minute (rpm). Optical micrographs confirm the decrease in the phase fraction of corrosion-sensitive β phase in the microstructure of C95800 after annealing, which, in turn, enhances the corrosion resistance of the alloy. Electrochemical studies including open circuit potentiometry, potentiodynamic polarization, and electrochemical impedance spectroscopy are performed to assess the effect of flow rate and heat treatment on the corrosion of samples at 25 and 40 °C in 3.5 wt% NaCl solution. For both as-cast and heat-treated samples, increasing the flow rate (i.e., electrode rotating rate) linearly reduces the corrosion resistance, indicating that the metal dissolution rate is significantly affected by hydrodynamic flow. Increasing the solution temperature negatively impacts the corrosion behavior of the as-cast and heat-treated samples at all flow conditions.

scholarly journals Influence of the Generator in-Growth Time on the Final Radiochemical Purity and Stability of Radiopharmaceuticals

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
L. Uccelli ◽  
A. Boschi ◽  
M. Pasquali ◽  
A. Duatti ◽  
G. Di Domenico ◽  
...  
Keyword(s):  
Nuclear Physics ◽  
Radiochemical Purity ◽  
Specific Activity ◽  
Growth Time ◽  
Direct Production ◽  
Theoretical Investigations ◽  
Standard Quality ◽  
Control Procedures ◽  
Italian National Institute ◽  
Preliminary Irradiation

At Legnaro laboratories of the Italian National Institute for Nuclear Physics (INFN), a feasibility study has started since 2011 related to accelerated-based direct production of by the100Mo(p,2n) reaction. Both theoretical investigations and some recent preliminary irradiation tests on100Mo-enriched samples have pointed out that both the / ratio and the specific activity will be basically different in the final accelerator-produced Tc with respect to generator-produced one, which might affect the radiopharmaceutical procedures. The aim of this work was to evaluate the possible impact of different / isomeric ratios on the preparation of different Tc-labeled pharmaceutical kits. A set of measurements with , eluted from a standard99Mo/ generator, was performed, and results on both radiochemical purity and stability studies (following the standard quality control procedures) are reported for a set of widely used pharmaceuticals (i.e., -Sestamibi, -ECD, -MAG3, -DTPA, -MDP, -HMDP, -nanocolloids, and -DMSA). These pharmaceuticals have been all reconstituted with either the first [O4]−eluate obtained from a99Mo/ generator (coming from two different companies) or eluates after 24, 36, 48, and 72 hours from last elution. Results show that the radiochemical purity and stability of these radiopharmaceuticals were not affected up to the value of 11.84 for the / ratio.

Self-radiation induced exchange between tritiated water and organic compounds. The labelling of L-chiro-inositol, myo-inositol and Hexa-O-methyl-L-chiro-inositol

1975 ◽  
Vol 28 (9) ◽  
pp. 1981 ◽  
Author(s):  
DHT Fong ◽  
CL Bodkin ◽  
MA Long ◽  
JL Garnett
Keyword(s):  
Organic Compounds ◽  
Radiochemical Purity ◽  
Specific Activity ◽  
Tritiated Water ◽  
High Specific Activity ◽  
Methyl Derivative ◽  
Radiation Induced ◽  
By Products ◽  
Gas Exposure

The stereochemistry of the tritiation of L-chiro-inositol, myo-inositol and hexa-O-methyl-L-chiro-inositol by self-radiation induced exchange with tritiated water of high specific activity has been investigated. Predominance of configurational retention was found to accompany tritium labelling in the two inositols, while substantial configurational inversion occurred in the hexa-O-methyl derivative. Tritiation occurred predominantly at C 1 in L-chiro-inositol, with slight inversion at this position alone accompanying the labelling. Comparison with Wilzbach T2 gas exposure results indicates the HTO method yields less by-products, myo-inositol having a radiochemical purity of 97%.

scholarly journals A Method for Leukokinetic Study in the Nonsteady State

Blood ◽  
1971 ◽  
Vol 38 (3) ◽  
pp. 302-311 ◽  
Author(s):  
G. ROTHSTEIN ◽  
C. R. BISHOP ◽  
J. W. ATHENS ◽  
H. E. ASHENBRUCKER
Keyword(s):  
Flow Rate ◽  
Early Phase ◽  
Specific Activity ◽  
Citrate Solution ◽  
Cell Agglutination ◽  
Nonsteady State ◽  
Radioactive Assay ◽  
Neutrophil Kinetics

Abstract In these studies, the DF32P leukokinetic technique has been modified so that neutrophil kinetics may be studied in the nonsteady state. In order to achieve this modification, an acid citrate solution was used in preparing leukocytes for radioactive assay. This results in a suspension free of cell agglutination so that a specific activity related only to neutrophils is obtained. This technique has been successfully employed in the study of the early phase of cortisol-induced granulocytosis, allowing measurement of cell flow rate in and out of the circulating granulocyte pool. This method is also useful in the study of subjects with pronounced neutropenia.

Radiosynthesis of a Novel PET Fluoronicotinamide for Melanoma Tumour PET Imaging; [18F]MEL050

2011 ◽  
Vol 64 (7) ◽  
pp. 873 ◽  
Author(s):  
Ivan Greguric ◽  
Stephen Taylor ◽  
Tien Pham ◽  
Naomi Wyatt ◽  
Cathy D. Jiang ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Large Scale ◽  
Radiochemical Purity ◽  
Specific Activity ◽  
Phase 1 ◽  
Radiochemical Yield ◽  
Synthesis Time ◽  
Clinical Phase ◽  
One Step ◽  
No Carrier Added

[18F]6-Fluoro-N-[2-(diethylamino)ethyl]nicotinamide [18F]MEL050 is a novel nicotinamide-based radiotracer, designed to target random metastatic dissemination of melanoma tumours by targeting melanin. Preclinical studies suggest that [18F]MEL050 has an excellent potential to improve diagnosis and staging of melanoma. Here we report the radiochemical optimization conditions of [18F]MEL050 and its large scale automated synthesis using a GE FXFN automated radiosynthesis module for clinical, phase-1 investigation. [18F]MEL050 was prepared via a one-step synthesis using no-carrier added K[18F]F-Krytpofix® 222 (DMSO, 170°C, 5 min) followed by HPLC purification. Using 6-chloro-N-[2-(diethylamino)ethyl]nicotinamide as precursor, [18F]MEL050 was obtained in 40–46% radiochemical yield (non-decay corrected), in greater than 99.9% radiochemical purity and specific activity ranging from 240 to 325 GBq μmol–1. Total synthesis time including formulation was 40 min and [18F]MEL050 was stable (99.8%) in PBS for 6 h.

An improved ultrafiltration method for free thyroxine and triiodothyronine in serum.

1980 ◽  
Vol 26 (1) ◽  
pp. 159-162 ◽  
Author(s):  
J Sophianopoulos ◽  
I Jerkunica ◽  
C N Lee ◽  
D Sgoutas
Keyword(s):  
Radiochemical Purity ◽  
Specific Activity ◽  
Equilibrium Dialysis ◽  
Free Ligand ◽  
High Specific Activity ◽  
Free Thyroxine ◽  
Free Triiodothyronine ◽  
Men And Women ◽  
Adult Men ◽  
Hyperthyroid Patients

Abstract We describe an ultrafiltration technique for rapidly and directly determining free triiodothyronine or free thyroxine, or both. After equilibrating serum at 37 degrees C with purified tracer of high specific activity, we placed 0.15 mL of serum in 2.8 mL of phosphate buffer (0.1 mol/L, pH 7.4) in the ultrafiltration cell and obtained successive 0.2- and 0.6-mL fractions of protein-free ultrafiltrate. Under our conditions free ligand concentration was independent of flow rate. After purifying the second fraction with protein-coated charcoal, we could determine the proportion of free triiodothyronine or free thyroxine. Samples from normal adult men and women, including women who were taking oral contraceptives or were pregnant, and from hypo- and hyperthyroid patients gave results that agreed with those obtained by equilibrium dialysis. Speed is the main advantage of the method: one technologist can complete the procedure in 2 h and, using a multi-micro-ultrafiltration system, can process many samples in one day. For laboratories where index-type reactions are performed routinely and direct free triiodothyronine or free thyroxine is determined only on selected specimens, this method is superior to dialysis. It is also very convenient for rapidly purifying tracers, to at least 97% radiochemical purity, with 94% recovery and no dilution.

Liquid and protein dynamics using a new minimally invasive pleural catheter in rabbits

1992 ◽  
Vol 72 (3) ◽  
pp. 851-857 ◽  
Author(s):  
V. C. Broaddus ◽  
M. Araya
Keyword(s):  
Minimally Invasive ◽  
Flow Rate ◽  
Protein Concentration ◽  
Liquid Flow Rate ◽  
Specific Activity ◽  
Total Radioactivity ◽  
Pleural Space ◽  
Liquid Volume ◽  
Protein Marker ◽  
Pleural Catheter

To obtain continuous access to the pleural space without causing injury, we tested a new transdiaphragmatic pleural catheter for its ability 1) to drain the pleural space without injury and 2) to drain liquid at a rate equal to normal pleural liquid production. In 13 anesthetized rabbits, we opened the abdomen and dissected through the diaphragm to insert a flared-tip catheter into the ventral pleural space on one side and then turned the rabbit prone. In 10 of the rabbits (8 for 6 h, 2 for 24 h), we continuously collected draining pleural liquid, and in 3 rabbits (6 h), we did not open the catheter. We injected radiolabeled albumin intravenously as a protein marker. Terminally, we collected pleural liquid from both pleural spaces and lavaged for total radioactivity. In 14 awake control rabbits without catheters, we measured normal pleural liquid production by the rate of equilibration of radiolabeled albumin from plasma to pleural liquid. We found that, although the percentage of neutrophils was increased on the side with the catheter (54 vs. 1% in control rabbits), the pleural liquid volume, protein concentration, specific activity of albumin, and total radioactivity in the pleural space were the same on the side with the catheter as on the opposite side and in the control rabbits. The liquid flow rate through the catheter over 6 h was 53 +/- 23 microliters/h [0.017 +/- 0.008 (SD) ml.kg-1.h-1], which was not significantly different from the computed rate of normal pleural liquid production in the control rabbits, 49 +/- 14 microliters/h (0.016 +/- 0.004 ml.kg-1.h-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Synthesis of 18F-labelled 2-fluoroethyl-nitrosoureas

1984 ◽  
Vol 62 (11) ◽  
pp. 2107-2112 ◽  
Author(s):  
Simin Farrokhzad ◽  
Mirko Diksic ◽  
Lucas Y. Yamamoto ◽  
William Feindel
Keyword(s):  
Radiochemical Purity ◽  
Specific Activity ◽  
Radiochemical Yield ◽  
Nucleophilic Attack ◽  
Aziridine Ring ◽  
Geometrical Isomers ◽  
Isomeric Mixture

18F-labelled 1,3-bis-(2-fluoroethyl) nitrosourea (18F-BFNU) (9) and 1-(2-chloroethyl)-3-(2-fluoroethyl) nitrosourea (18F-CFNU) (isomeric mixture, 11,12) were synthesized by nucleophilic attack of 18F-labelled tetra-n-butylammonium fluoride on the aziridine ring of 1,3-substituted ureas. Diethyleneurea (DEU) (5), 1-(2-fluoroethyl)-3-ethyleneurea (FEU) (7), and 1-(2-chloroethyl)-3-ethyleneurea (CEU) (14) were used as starting materials in the synthesis. Nitrosation of 18F-labelled 1,3-bis-(2-fluoroethyl) urea (18F-BFU) (6) produced 18F-BFNU with a radiochemical yield of 5–10%. Nitrosation of 18F-labelled 1-(2-chloroethyl)-3-(2-fluoroethyl) urea (18F-CFU) (15) gave 18F-CFNU as a mixture of two isomers. Geometrical isomers of CFNU were separated by hplc, and the radiochemical yield of the two isomers ranged from 8% to 15%, with a radiochemical purity exceeding 96%. Syntheses, which took about 60 min, yielded products with specific activity of 680 mCi/mmol when n-Bu4N+F− was used, or 300 mCi/mmol when HF was used to complete the opening of the aziridine ring.

Sorption Behavior of Neptunium on Bentonite-Effect of Calcium Ion on the Sorption -

1994 ◽  
Vol 353 ◽  
Author(s):  
Naofumi Kozai ◽  
Toshihiko Ohnuki ◽  
Susumu Muraoka
Keyword(s):  
Distribution Coefficient ◽  
Sorption Capacity ◽  
Calcium Ion ◽  
Strong Acid ◽  
Sorption Behavior ◽  
Exchangeable Cation ◽  
Batch Type ◽  
Ph Range

AbstractThe sorption behavior of neptunium on bentonite was studied with batch type sorption and desorption experiments over a pH range of 2 to 8. A series of parallel studies using Na-smectite, Ca-smectite and admixtures of Na-smectite and calcite quantified the capacity of Ca2+ (which occurs in bentonite as an exchangeable cation of smectite and as a component of calcite) to inhibit the sorption of neptunium. The distribution coefficient (Kd) of neptunium for bentonite was constant from pH 2 to 7, while for pure Na-smectite Kd increased below pH 5 due to “specific sorption” of neptunium on Na-smectite. Specific sorption was defined as occurring when neptunium could be desorbed by a strong acid (1 M HCl) but was stable in the presence of 1 M KCl. It was found that the quantity of neptunium sorbed on Na-smectite was inversely proportional to the concentration of Ca2+ in solution, an effect most pronounced at pH <5. These results show that Ca2+ limits the specific sorption capacity of Na-smectite for neptunium. Similarly, in the mixture of Na-smectite and calcite, sufficient Ca2+ was solubilized to depress neptunium sorption. This investigation demonstrates that Ca2+ contained in bentonite as exchangeable cation and released from calcite reduces the specific sorption of neptunium.

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