The adsorption behaviour of Mo tagged with99Mo (in the form of molybdate and phosphomolybdate) and99mTc as pertechnetate werw measured using silver-coated carbon, activated carbon and an equal mixture of both at HNO3 concentrations ranging from 0.01 to 2M. It was found that, on activated carbon and silver-coated carbon, molybdate and phosphomolybdate
have high absorption values at 0.01 M HNO3 and activated carbon has a high adsorption value for99mTcO
at the same low acid concentration. The capacity of Ag−C, C and Ag−C/C for molybdate at pH 2–3 has been found to be 240 mg
MoO3/g, 320 mg MoO3/g and 360 mg MoO3/g, respectively. For phosphomolybdate, the capacity of the same substrates at pH2–3 was found to be 550 mg MoO3/g, 650 mg MoO3/g and 1000 mg MoO3/g, respectively. These results indicate that with phosphomolybdate the capacity of Mo on the substrates is 2–3 times higher
than with molybdate.
Extraction of Eu3+ from 0.1M aqueous perchlorate medium by thenoyltrifluoroacetone (HTTA) and by mixtures of HTTA and tributylphosphate (TBP), HTTA and triphenylphosphine oxide (TPPO), HTTA and trioctylphosphine oxide (TOPO) and HTTA and triphenylarsine oxide (TPAsO) has been studied at various temperatures allowing for the elucidation of the mechanism of extraction in each case and a comparison between the various bases.
Authors:N. Botros, S. El-Bayoumy, M. El-Garhy, and S. Marei
Adsorption behaviour of Sm3+, Gd3+, Tb3+ and Tm3+ on potassium zinc hexacyanoferrate (PZF) was investigated. The effect of K+ and Zn2+ concentrations on the distribution coefficient was studied. The mechanism of ion exchange and possible separation of the lanthanides used are discussed.
Authors:M. Shehata, S. El-Bayoumy, and M. El-Garhy
The distribution of Mo(VI) and the interfering radiocontaminants U(VI), Zr(IV) and Nb(V) have been investigated between chromatographic
alumina and aqueous hydrochloric acid solutions of concentrations ranging from 0.5M to 11M. At low acidities (less than 1M HCl) the distribution coefficients increase with the decrease of acid concentration, while in the region of 2–4M they increase with the increase of the acid concentration. Above 4M HCl, the increase inKD continues with the acid concentration for both Zr(IV) and Nb(V), but constant values are reached for U(VI) and Mo(VI).
Authors:E. Hallaba, S. El-Bayoumy, and G. El-Shaboury
The exchange of Rose-Bengal in the mono-sodium salt with elementary131I in an organic medium allows for the preparation of a labelled product substantially higher in radiochemical purity than
that produced by other methods. Purification of the starting material before the labelling process has been done by adsorption
chromatography. Under the conditions described a radiochemical yield more than 97% can be obtained within 30–60 minutes. The
product was stable during sterilization and storage for 10 days and was found to be free of131I.
The extractability of99Mo-molybdophosphoric acid H3/PMo12O40/ and99mTc-pertechnetic acid /PTcO4/ in 20% (v/v) bis /2-ethylhexyl/ phosphoric acid /HDEHP/ in benzene has been investigated at different concentrations of HCl, HBr and HNO3 acids. The effect of extractant concentration and diluent on the extractability of molybdophosphoric and pertechnetic acids with 20% (v/v) HDEHP in benzene from different concentrations of HCl acid has also been studied.99Mo-molybdo-phosphoric acid was found to be selectively extracted and separated from99mTc-pertechnetic acid with 20% HDEHP in benzene at an acidity of about 0.49M HCl, HBr and HNO3. The extractability of H3/PMo12O40/ from these acids generally follows the decreasing order HBr>HCl>HNO3. The separation factors /Kd molybdophosphoric/Kd pertechnetic/ were found to be 12.9×105 and 7.6×105 for HBr and HCl, respectively. The extractability of pertechnetic acid follows the order HCl>HBrHNO3. Benzene is the diluent due to its radiation stability. A new procedure for the separation of99mTc from99Mo was suggested.
Authors:G. El-Shaboury, K. Farah, and S. El-Bayoumy
The present investigation deals with a study of the isotope exchange reaction of iodine between sodium iodide [Na131I] and [4-127I]iodoantipyrine in organic medium, using different iodinating radioiodine reagents of different carrier-iodine concentration. A maximum saturation yield over 90% of pure [4-131I]iodoantipyrine has been obtained by performing the isotope exchange reaction in ethanol at 80°C in 30 min. The same yield has been obtained using the same concentrations by performing the reaction at room temperature (17–20°C) for 3 h. Also the rate of the isotope exchange reaction was found to be carrier-iodine dependent as well as time and temperature dependent. According to these results and reaction conditions, a kit form method was elaborated for the synthesis of [4-131I]iodoantipyrine as well as [4-123I]iodoantipyrine.
Authors:M. El-Garhy, M. Shehata, and S. El-Bayoumy
The radioisotope99Mo generated through the fission of neutron-irradiated uranium targets was separated in an extremely radiochemically pure
state. The target dissolution mixture was run on a silica gel column whereby the95Zr−95Nb activity, the serious radiocontaminants of99Mo, was adsorbed on the gel. The effluent from the gel column was processed and treated with sodium dihydrogen phosphate.
The processed solution was run on an activated alumina column whereby99Mo was adsorbed as phospho-molybdate complex ion, then desorbed from the column as the molybdate ion by eluting with 10% NaOH
solution. By recycling the adsorption and desorption steps on alumnia,99Mo was finally obtained totally free from all other radiocontaminants.
Authors:M. El-Garhy, M. Shehata, and S. El-Bayoumy
Dissolution of a neutron-irradiated uranium target in a medium of 6N HCl containing a few drops of very dilute HNO3 yielded a matrix solution which on running on a silica gel column allowed the complete adsorption of the95Zr−95Nb activity formed in the fission process. The95Zr−95Nb activity is cleanly and totally eluted with 0.5% oxalic acid solution. None of the uranium or the activity of the other
fission products was found to be adsorbed on the column.
Authors:N. Farouk, M. El-Tawoosy, S. Ayoub, and A. El-Bayoumy
Celecoxib was labelled effectively with 99mTc. The labeling yield was found to be influenced by the amount of celecoxib, the amount of stannous chloride dihydrate, the
reaction time, the temperature and the pH of the reaction mixture. The importance of stannous chloride dihydrate arises from
its function as a reducing agent for pertechnetate to form complex celecoxib. The suitable amount required to produce high
labeling yield of 99mTc-celecoxib was 500 μg SnCl2·2H2O. The pH of the reaction medium was found to play a significant role in this labeling process. The labeling reaction was
performed at a neutral medium (pH 7). The labeling reaction proceeds well at room temperature (25 ± 1 °C) and the complex
decomposes by heat. The labeled celecoxib (99mTc-celecoxib) showed a good localization in inflamed foci and a good imaging must be taken 4 h post injection.