Rubel Chakravarty | Bhabha Atomic Research Centre (original) (raw)
Papers by Rubel Chakravarty
Chromatographia, Jan 1, 2011
Abstract The present work demonstrates the utility of polymer embedded nanocrystalline titania (T... more Abstract The present work demonstrates the utility of polymer embedded nanocrystalline titania (TiP) as a new, accessible and viable solid sorbent for the chromatographic separation of high specific activity 77 As from neutron irradiated natural GeO 2. ...
… of Chromatography A, Jan 1, 2011
Barium-137m availed from a (137)Cs/(137m)Ba generator is an attractive industrial radiotracer for... more Barium-137m availed from a (137)Cs/(137m)Ba generator is an attractive industrial radiotracer for liquid flow rate measurement owing to its short half-life (T(1/2)=2.5 min) and emission of highly energetic gamma radiation (E(γ)=661.7 keV). Ammonium molybdophosphate (AMP) impregnated alumina microspheres (AMP-Al(2)O(3)), an engineered form of sorbent material was synthesized by Gel Entrapment Technique (GET). The utility of the material in the preparation of (137)Cs/(137m)Ba generator was evaluated. Various experimental parameters were optimized for efficient retention of (137)Cs and selective elution of (137m)Ba. A chromatographic 0.74 GBq (20 mCi) (137)Cs/(137m)Ba generator was developed using this material and its performance was evaluated for 6 months. Barium-137m could be eluted from the generator using 0.1 M NH(4)NO(3)+0.5 M HNO(3) solution with >80% yield and with acceptable radionuclidic purity suitable for industrial radiotracer investigations.
Journal of Radioanalytical …, Jan 1, 2011
Abstract A novel electrochemical process to avail clinical grade 99m Tc from (n, γ) 99 Mo has bee... more Abstract A novel electrochemical process to avail clinical grade 99m Tc from (n, γ) 99 Mo has been demonstrated. The electrochemical parameters were optimized to maximize the 99m Tc yield with minimal 99 Mo contamination. 99 Mo/99m Tc generators containing up ...
Applied Radiation and …, Jan 1, 2011
... generator performance. Radiochim. Acta. 92, 259-264. 16 Sarkar, SK, Saraswathy, P.,Arjun, G, ... more ... generator performance. Radiochim. Acta. 92, 259-264. 16 Sarkar, SK, Saraswathy, P.,Arjun, G, Ramamoorthy, N., 2004. ... generator performance. Radiochim. Acta. 92, 259-264. 16 Sarkar, SK, Saraswathy, P., Arjun, G, Ramamoorthy, N., 2004. ...
Applied Radiation and …, Jan 1, 2011
Radiochimica …, Jan 1, 2012
... radionuclidic impurities [7]. As 169Yb decays by electron capture route (100% electron captur... more ... radionuclidic impurities [7]. As 169Yb decays by electron capture route (100% electron capture, T1/2 = 32 d) followed by the emission of low energy gamma photons [Eγ = 177 keV (22.5%), 197 keV (35.9%)] to stable 169Tm, the presence of 169Yb in 175Yb is not ex-pected to ...
Analytical …, Jan 1, 2011
The (188)W/(188)Re generator using an acidic alumina column for chromatographic separation of (18... more The (188)W/(188)Re generator using an acidic alumina column for chromatographic separation of (188)Re has remained the most popular procedure world over. The capacity of bulk alumina for taking up tungstate ions is limited (∼50 mg W/g) necessitating the use of very high specific activity (188)W (185-370 GBq/g), which can be produced only in very few high flux reactors available in the world. In this context, the use of high-capacity sorbents would not only mitigate the requirement of high specific activity (188)W but also facilitate easy access to (188)Re. A solid state mechanochemical approach to synthesize nanocrystalline γ-Al(2)O(3) possessing very high W-sorption capacity (500 mg W/g) was developed. The structural and other investigations of the material were carried out using X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer Emmett Teller (BET) surface area analysis, thermogravimetric-differential thermal analysis (TG-DTA), and dynamic light scattering (DLS) techniques. The synthesized material had an average crystallite size of ∼5 nm and surface area of 252 ± 10 m(2)/g. Sorption characteristics such as distribution ratios (K(d)), capacity, breakthrough profile, and elution behavior were investigated to ensure quantitative uptake of (188)W and selective elution of (188)Re. A 11.1 GBq (300 mCi) (188)W/(188)Re generator was developed using nanocrystalline γ-Al(2)O(3), and its performance was evaluated for a period of 6 months. The overall yield of (188)Re was >80%, with >99.999% radionuclidic purity and >99% radiochemical purity. The eluted (188)Re possessed appreciably high radioactive concentration and was compatible for the preparation of (188)Re labeled radiopharmaceuticals.
Applied Radiation and …, Jan 1, 2009
A novel method to prepare 90 Y-EGMP patches has been developed for brachytherapy applications.EGM... more A novel method to prepare 90 Y-EGMP patches has been developed for brachytherapy applications.EGMP films of 1 cm  1 cm size, incorporating $185 MBq of 90 Y were prepared and sealed between thin plastic sheets with uniform distribution of 90 Y. The leachability of 90 Y from radioactive patches was less than 0.01%. There was no leakage of radioactivity from radioactive patches, when tested in water or saline. The studies related to establish therapeutic efficacy of these patches are warranted.
Nuclear Medicine and …, Jan 1, 2011
Most of the commercially available (68)Ge/(68)Ga generator systems are not optimally designed for... more Most of the commercially available (68)Ge/(68)Ga generator systems are not optimally designed for direct applications in a clinical context. We have developed a nano-zirconia based (68)Ge/(68)Ga generator system for accessing (68)Ga amenable for the preparation of radiopharmaceuticals. Nano-zirconia was synthesized by the in situ reaction of zirconyl chloride with ammonium hydroxide in alkaline medium. The physical characteristics of the material were studied by various analytical techniques. A 740 MBq (20 mCi) (68)Ge/(68)Ga generator was developed using this sorbent and its performance was evaluated for a period of 1 year. The suitability of (68)Ga for labeling biomolecules was ascertained by labeling DOTA-TATE with (68)Ga. The material synthesized was nanocrystalline with average particle size of ~7 nm, pore-size of ~4 Å and a high surface area of 340±10 m(2) g(-1). (68)Ga could be regularly eluted from this generator in 0.01N HCl medium with an overall radiochemical yield >80% and with high radionuclidic (<10(-5)% of (68)Ge impurity) and chemical purity (<0.1 ppm of Zr, Fe and Mn ions). The compatibility of the product for preparation of (68)Ga-labeled DOTA-TATE under the optimized reaction conditions was found to be satisfactory in terms of high labeling yields (>99%). The generator gave a consistent performance with respect to the elution yield and purity of (68)Ga over a period of 1 year. The feasibility of preparing an efficient (68)Ge/(68)Ga generator which can directly be used for biomedical applications has been demonstrated.
Chromatographia, Jan 1, 2010
The feasibility of using tetragonal nano-zirconia (t-ZrO 2 ) as an effective sorbent for developi... more The feasibility of using tetragonal nano-zirconia (t-ZrO 2 ) as an effective sorbent for developing a 99 Mo/ 99m Tc chromatographic generator was demonstrated. The structural characteristics of the sorbent matrix were investigated by different analytical techniques such as XRD, BET surface area analysis, FT-IR, TEM etc. The material synthesized was nanocrystalline, in tetragonal phase with an average particle size of *7 nm and a large surface area of 340 m 2 g -1 . The equilibrium sorption capacity of t-ZrO 2 is >250 mg Mo g -1 . The present study indicates that 99 Mo is both strongly and selectively retained by t-ZrO 2 at acidic pH and 99m Tc could be readily eluted from it, using 0.9% NaCl solution. A 9.25 GBq (250 mCi) t-ZrO 2 based chromatographic 99 Mo/ 99m Tc generator was developed and its performance was repeatedly evaluated for 10 days. 99m Tc could be eluted with >85% yield having acceptable radionuclidic, radiochemical and chemical purity for clinical applications. The compatibility of the product in the preparation of 99m Tc labeled formulations such as 99m Tc-EC and 99m Tc-DMSA was evaluated and found to be satisfactory.
… Applied Materials & …, Jan 1, 2010
The (68)Ge/(68)Ga generator has high potential for clinical positron emission tomography (PET) im... more The (68)Ge/(68)Ga generator has high potential for clinical positron emission tomography (PET) imaging. However, because of the unavailability of a suitable sorbent material, the commercially available (68)Ge/(68)Ga generators are not directly adaptable for the preparation of (68)Ga-labeled radiopharmaceuticals. In view of this, a new nanoceria-polyacrylonitrile (PAN) composite sorbent has been synthesized by decomposition of a cerium oxalate precursor to cerium oxide and its subsequent incorporation in PAN matrix for the development of a clinical grade (68)Ge/(68)Ga generator. The X-ray diffraction (XRD) studies and BET nitrogen adsorption technique revealed that nanocrystalline ceria had an average particle size of approximately 10 nm, surface area of 72 +/- 3 m(2)/g and an average pore size of 3.8 +/- 0.1 A. Investigation of the distribution ratio (K(d)) values for the prepared sorbent in 0.01 N HCl medium revealed the suitability of the sorbent for the quantitative retention of (68)Ge and efficient elution of clinical grade (68)Ga. A 370 MBq (10 mCi) (68)Ge/(68)Ga chromatographic generator was developed using this sorbent. (68)Ga could be regularly eluted from this generator with >80% elution yield. The eluted (68)Ga possess high radionuclidic purity (<1 x 10(-5)% of (68)Ge impurity), chemical purity (<0.1 ppm of Ce, Fe and Mn ions) and was amenable for the preparation of (68)Ga-labeled radiopharmaceuticals. The generator gave a consistent performance with respect to the elution yield and purity of (68)Ga over an extended period of 7 months.
Applied Radiation and …, Jan 1, 2010
High specific activity 188 Re required for nuclear medicine is mostly obtained from 188 W/ 188 Re... more High specific activity 188 Re required for nuclear medicine is mostly obtained from 188 W/ 188 Re generators. As the parent radionuclide 188 W is of low specific activity (o 185 GBq/g), a relatively large volume of 0.9% saline is required for the elution of 188 Re. Post-elution concentration is needed in order to increase the radioactive concentration of the eluted 188 Re. An electrochemical procedure to concentrate 188 Re suitable for the preparation of radiopharmaceuticals is developed. 188 Re eluted from an alumina generator could be concentrated $ 100 fold, and it could be used to label DMSA and HEDP with 4 98% yield.
Chromatographia, Jan 1, 2009
An industrial chromatographic 99 Mo-99m Tc generator has been developed with the aid of chromatog... more An industrial chromatographic 99 Mo-99m Tc generator has been developed with the aid of chromatographic alumina to obtain 99m Tc in a non-aqueous medium. This generator system takes advantage of tributyl phosphate to extract 99m Tc selectively with appreciable yield and in high radiochemical and radionuclidic purity. This facile, versatile and efficient approach provides 99m Tc at industrial sites in a medium soluble in hydrocarbon solvents, for radiotracer applications.
Applied Radiation and …, Jan 1, 2008
Article in Applied radiation and isotopes: including data, instrumentation and methods for use in... more Article in Applied radiation and isotopes: including data, instrumentation and methods for use in agriculture, industry and medicine · a b s t r a c t 60 Co sources (37 kBq) in the form of a thin film are widely used in position identification of perforation in offshore oil-well explorations. This paper describes the large-scale preparation of such sources using a radioactive polymer containing 60 Co. 60 Co was extracted into chloroform containing 8-hydroxyquinoline. The chloroform layer was mixed with polymethyl methacrylate (PMMA) polymer. A large film was prepared using the polymer solution containing the complex. The polymer film was then cut into circular sources, mounted on a source holder and supplied to various users.
Nuclear medicine and …, Jan 1, 2010
Introduction: A novel two-step separation process for the production of no-carrier-added (NCA) 17... more Introduction: A novel two-step separation process for the production of no-carrier-added (NCA) 177 Lu from neutron irradiated Yb target through an electrochemical pathway employing mercury-pool cathode has been developed. Methods: A two-cycle electrolysis procedure was adopted for separation of 177 Lu from 177 Lu/Yb mixture in lithium citrate medium. The influence of different experimental parameters on the separation process was investigated and optimized for the quantitative deposition of Yb in presence of 177 Lu. The first electrolysis was performed for 50 min in the 177 Lu/Yb feed solution at pH 6 applying a potential of 8 V using platinum electrode as anode and mercury as the cathode. The second electrolysis was performed under the same conditions using fresh electrodes. The radionuclidic and chemical purity of 177 Lu was determined by using gamma ray spectrometry and atomic absorption spectrometry. The suitability of 177 Lu for biomedical applications was ascertained by labeling 1,4,7,10-tetraazacyclododecane-1,4,7,10tetraacetic acid D-Phe 1 -Tyr 3 -octreotate(DOTA-TATE) with 177 Lu. Results: This process could provide NCA 177 Lu with N99.99% radionuclidic purity and an overall separation yield of ∼99% was achieved within 3-4 h. The Hg content in the product was determined to be b1 ppm. Radiolabeling yield of N98% was obtained with DOTA-TATE under the optimized reaction conditions. Conclusions: An efficient strategy for the separation of NCA 177 Lu, suitable for biomedical applications, has been developed.
![Research paper thumbnail of A novel electrochemical technique for the production of clinical grade 99mTc using (n,[gamma]) 99Mo](https://attachments.academia-assets.com/51126959/thumbnails/1.jpg)
](Nuclear medicine and biology, Jan 1, 2010
Introduction: In order to meet the growing demand for 99m Tc and to reduce the reliance on fissio... more Introduction: In order to meet the growing demand for 99m Tc and to reduce the reliance on fission-produced 99 Mo, an electrochemical pathway for accessing 99m Tc through the (n, γ) 99 Mo was explored as a back-up measure and to supplement 99m Tc supply for radiopharmaceuticals application. Methods: 99m Tc from an equilibrium mixture of 99 Mo/ 99m Tc was selectively deposited on a platinum cathode in an electrochemical cell by applying optimal voltage and stripped back again into the 0.9% saline solution. The radiochemical and radionuclidic purity of the product were determined using standard techniques. 99m Tc thus obtained was used for labeling standard ligands such as dimercaptosuccinic acid (DMSA) and ethylene dicysteine (EC), to ascertain the usability. Results: Selective deposition of 99m Tc on the platinum electrode was achieved at a potential of 5 V over a period of 1 h in NaOH electrobath. The overall yield of 99m Tc was N90%, with N99.99% radionuclidic purity and N99% radiochemical purity. The performance of the generator remained consistent over a period of 10 days. The compatibility of the product in the preparation of 99m Tc-labeled formulations such as 99m Tc-DMSA and 99m Tc-EC was found to be satisfactory in terms of high labeling yields (N98%). Conclusion: A novel and attractive method has been developed to obtain highly concentrated 99m Tc, without using fission-produced 99 Mo.
Chromatographia, Jan 1, 2009
Currently, 188 Re is obtained from 188 W/ 188 Re chromatographic generator containing alumina whi... more Currently, 188 Re is obtained from 188 W/ 188 Re chromatographic generator containing alumina which has a limited capacity (*80 mg Wg -1 ) for 188 W. This results in high bolus volumes of 188 Re, which often needs to be concentrated before radiolabeling. We have demonstrated the feasibility of using polymer embedded nano crystalline titania (TiP), a novel high capacity sorbent material (*300 mg Wg -1 ), for developing a 188 W/ 188 Re chromatographic generator. A TiP based chromatographic 188 W/ 188 Re generator was developed in which 188 Re could be eluted with 0.9% saline solution. About 90% of the 188 Re could be recovered in the first 4-5 mL of total activity with more than 80% yield. The purity of 188 Re is adequate for clinical applications.
Radiochimica …, Jan 1, 2009
Abstract Rhenium-188 is a well recognized therapeutic radionuclide and its use in a variety of ap... more Abstract Rhenium-188 is a well recognized therapeutic radionuclide and its use in a variety of applications has been reported. The current methods of obtaining no-carrier added 188Re from conventional alumina based generators require 188W of very high specific ...
Chromatographia, Jan 1, 2011
Abstract The present work demonstrates the utility of polymer embedded nanocrystalline titania (T... more Abstract The present work demonstrates the utility of polymer embedded nanocrystalline titania (TiP) as a new, accessible and viable solid sorbent for the chromatographic separation of high specific activity 77 As from neutron irradiated natural GeO 2. ...
… of Chromatography A, Jan 1, 2011
Barium-137m availed from a (137)Cs/(137m)Ba generator is an attractive industrial radiotracer for... more Barium-137m availed from a (137)Cs/(137m)Ba generator is an attractive industrial radiotracer for liquid flow rate measurement owing to its short half-life (T(1/2)=2.5 min) and emission of highly energetic gamma radiation (E(γ)=661.7 keV). Ammonium molybdophosphate (AMP) impregnated alumina microspheres (AMP-Al(2)O(3)), an engineered form of sorbent material was synthesized by Gel Entrapment Technique (GET). The utility of the material in the preparation of (137)Cs/(137m)Ba generator was evaluated. Various experimental parameters were optimized for efficient retention of (137)Cs and selective elution of (137m)Ba. A chromatographic 0.74 GBq (20 mCi) (137)Cs/(137m)Ba generator was developed using this material and its performance was evaluated for 6 months. Barium-137m could be eluted from the generator using 0.1 M NH(4)NO(3)+0.5 M HNO(3) solution with >80% yield and with acceptable radionuclidic purity suitable for industrial radiotracer investigations.
Journal of Radioanalytical …, Jan 1, 2011
Abstract A novel electrochemical process to avail clinical grade 99m Tc from (n, γ) 99 Mo has bee... more Abstract A novel electrochemical process to avail clinical grade 99m Tc from (n, γ) 99 Mo has been demonstrated. The electrochemical parameters were optimized to maximize the 99m Tc yield with minimal 99 Mo contamination. 99 Mo/99m Tc generators containing up ...
Applied Radiation and …, Jan 1, 2011
... generator performance. Radiochim. Acta. 92, 259-264. 16 Sarkar, SK, Saraswathy, P.,Arjun, G, ... more ... generator performance. Radiochim. Acta. 92, 259-264. 16 Sarkar, SK, Saraswathy, P.,Arjun, G, Ramamoorthy, N., 2004. ... generator performance. Radiochim. Acta. 92, 259-264. 16 Sarkar, SK, Saraswathy, P., Arjun, G, Ramamoorthy, N., 2004. ...
Applied Radiation and …, Jan 1, 2011
Radiochimica …, Jan 1, 2012
... radionuclidic impurities [7]. As 169Yb decays by electron capture route (100% electron captur... more ... radionuclidic impurities [7]. As 169Yb decays by electron capture route (100% electron capture, T1/2 = 32 d) followed by the emission of low energy gamma photons [Eγ = 177 keV (22.5%), 197 keV (35.9%)] to stable 169Tm, the presence of 169Yb in 175Yb is not ex-pected to ...
Analytical …, Jan 1, 2011
The (188)W/(188)Re generator using an acidic alumina column for chromatographic separation of (18... more The (188)W/(188)Re generator using an acidic alumina column for chromatographic separation of (188)Re has remained the most popular procedure world over. The capacity of bulk alumina for taking up tungstate ions is limited (∼50 mg W/g) necessitating the use of very high specific activity (188)W (185-370 GBq/g), which can be produced only in very few high flux reactors available in the world. In this context, the use of high-capacity sorbents would not only mitigate the requirement of high specific activity (188)W but also facilitate easy access to (188)Re. A solid state mechanochemical approach to synthesize nanocrystalline γ-Al(2)O(3) possessing very high W-sorption capacity (500 mg W/g) was developed. The structural and other investigations of the material were carried out using X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer Emmett Teller (BET) surface area analysis, thermogravimetric-differential thermal analysis (TG-DTA), and dynamic light scattering (DLS) techniques. The synthesized material had an average crystallite size of ∼5 nm and surface area of 252 ± 10 m(2)/g. Sorption characteristics such as distribution ratios (K(d)), capacity, breakthrough profile, and elution behavior were investigated to ensure quantitative uptake of (188)W and selective elution of (188)Re. A 11.1 GBq (300 mCi) (188)W/(188)Re generator was developed using nanocrystalline γ-Al(2)O(3), and its performance was evaluated for a period of 6 months. The overall yield of (188)Re was >80%, with >99.999% radionuclidic purity and >99% radiochemical purity. The eluted (188)Re possessed appreciably high radioactive concentration and was compatible for the preparation of (188)Re labeled radiopharmaceuticals.
Applied Radiation and …, Jan 1, 2009
A novel method to prepare 90 Y-EGMP patches has been developed for brachytherapy applications.EGM... more A novel method to prepare 90 Y-EGMP patches has been developed for brachytherapy applications.EGMP films of 1 cm  1 cm size, incorporating $185 MBq of 90 Y were prepared and sealed between thin plastic sheets with uniform distribution of 90 Y. The leachability of 90 Y from radioactive patches was less than 0.01%. There was no leakage of radioactivity from radioactive patches, when tested in water or saline. The studies related to establish therapeutic efficacy of these patches are warranted.
Nuclear Medicine and …, Jan 1, 2011
Most of the commercially available (68)Ge/(68)Ga generator systems are not optimally designed for... more Most of the commercially available (68)Ge/(68)Ga generator systems are not optimally designed for direct applications in a clinical context. We have developed a nano-zirconia based (68)Ge/(68)Ga generator system for accessing (68)Ga amenable for the preparation of radiopharmaceuticals. Nano-zirconia was synthesized by the in situ reaction of zirconyl chloride with ammonium hydroxide in alkaline medium. The physical characteristics of the material were studied by various analytical techniques. A 740 MBq (20 mCi) (68)Ge/(68)Ga generator was developed using this sorbent and its performance was evaluated for a period of 1 year. The suitability of (68)Ga for labeling biomolecules was ascertained by labeling DOTA-TATE with (68)Ga. The material synthesized was nanocrystalline with average particle size of ~7 nm, pore-size of ~4 Å and a high surface area of 340±10 m(2) g(-1). (68)Ga could be regularly eluted from this generator in 0.01N HCl medium with an overall radiochemical yield >80% and with high radionuclidic (<10(-5)% of (68)Ge impurity) and chemical purity (<0.1 ppm of Zr, Fe and Mn ions). The compatibility of the product for preparation of (68)Ga-labeled DOTA-TATE under the optimized reaction conditions was found to be satisfactory in terms of high labeling yields (>99%). The generator gave a consistent performance with respect to the elution yield and purity of (68)Ga over a period of 1 year. The feasibility of preparing an efficient (68)Ge/(68)Ga generator which can directly be used for biomedical applications has been demonstrated.
Chromatographia, Jan 1, 2010
The feasibility of using tetragonal nano-zirconia (t-ZrO 2 ) as an effective sorbent for developi... more The feasibility of using tetragonal nano-zirconia (t-ZrO 2 ) as an effective sorbent for developing a 99 Mo/ 99m Tc chromatographic generator was demonstrated. The structural characteristics of the sorbent matrix were investigated by different analytical techniques such as XRD, BET surface area analysis, FT-IR, TEM etc. The material synthesized was nanocrystalline, in tetragonal phase with an average particle size of *7 nm and a large surface area of 340 m 2 g -1 . The equilibrium sorption capacity of t-ZrO 2 is >250 mg Mo g -1 . The present study indicates that 99 Mo is both strongly and selectively retained by t-ZrO 2 at acidic pH and 99m Tc could be readily eluted from it, using 0.9% NaCl solution. A 9.25 GBq (250 mCi) t-ZrO 2 based chromatographic 99 Mo/ 99m Tc generator was developed and its performance was repeatedly evaluated for 10 days. 99m Tc could be eluted with >85% yield having acceptable radionuclidic, radiochemical and chemical purity for clinical applications. The compatibility of the product in the preparation of 99m Tc labeled formulations such as 99m Tc-EC and 99m Tc-DMSA was evaluated and found to be satisfactory.
… Applied Materials & …, Jan 1, 2010
The (68)Ge/(68)Ga generator has high potential for clinical positron emission tomography (PET) im... more The (68)Ge/(68)Ga generator has high potential for clinical positron emission tomography (PET) imaging. However, because of the unavailability of a suitable sorbent material, the commercially available (68)Ge/(68)Ga generators are not directly adaptable for the preparation of (68)Ga-labeled radiopharmaceuticals. In view of this, a new nanoceria-polyacrylonitrile (PAN) composite sorbent has been synthesized by decomposition of a cerium oxalate precursor to cerium oxide and its subsequent incorporation in PAN matrix for the development of a clinical grade (68)Ge/(68)Ga generator. The X-ray diffraction (XRD) studies and BET nitrogen adsorption technique revealed that nanocrystalline ceria had an average particle size of approximately 10 nm, surface area of 72 +/- 3 m(2)/g and an average pore size of 3.8 +/- 0.1 A. Investigation of the distribution ratio (K(d)) values for the prepared sorbent in 0.01 N HCl medium revealed the suitability of the sorbent for the quantitative retention of (68)Ge and efficient elution of clinical grade (68)Ga. A 370 MBq (10 mCi) (68)Ge/(68)Ga chromatographic generator was developed using this sorbent. (68)Ga could be regularly eluted from this generator with >80% elution yield. The eluted (68)Ga possess high radionuclidic purity (<1 x 10(-5)% of (68)Ge impurity), chemical purity (<0.1 ppm of Ce, Fe and Mn ions) and was amenable for the preparation of (68)Ga-labeled radiopharmaceuticals. The generator gave a consistent performance with respect to the elution yield and purity of (68)Ga over an extended period of 7 months.
Applied Radiation and …, Jan 1, 2010
High specific activity 188 Re required for nuclear medicine is mostly obtained from 188 W/ 188 Re... more High specific activity 188 Re required for nuclear medicine is mostly obtained from 188 W/ 188 Re generators. As the parent radionuclide 188 W is of low specific activity (o 185 GBq/g), a relatively large volume of 0.9% saline is required for the elution of 188 Re. Post-elution concentration is needed in order to increase the radioactive concentration of the eluted 188 Re. An electrochemical procedure to concentrate 188 Re suitable for the preparation of radiopharmaceuticals is developed. 188 Re eluted from an alumina generator could be concentrated $ 100 fold, and it could be used to label DMSA and HEDP with 4 98% yield.
Chromatographia, Jan 1, 2009
An industrial chromatographic 99 Mo-99m Tc generator has been developed with the aid of chromatog... more An industrial chromatographic 99 Mo-99m Tc generator has been developed with the aid of chromatographic alumina to obtain 99m Tc in a non-aqueous medium. This generator system takes advantage of tributyl phosphate to extract 99m Tc selectively with appreciable yield and in high radiochemical and radionuclidic purity. This facile, versatile and efficient approach provides 99m Tc at industrial sites in a medium soluble in hydrocarbon solvents, for radiotracer applications.
Applied Radiation and …, Jan 1, 2008
Article in Applied radiation and isotopes: including data, instrumentation and methods for use in... more Article in Applied radiation and isotopes: including data, instrumentation and methods for use in agriculture, industry and medicine · a b s t r a c t 60 Co sources (37 kBq) in the form of a thin film are widely used in position identification of perforation in offshore oil-well explorations. This paper describes the large-scale preparation of such sources using a radioactive polymer containing 60 Co. 60 Co was extracted into chloroform containing 8-hydroxyquinoline. The chloroform layer was mixed with polymethyl methacrylate (PMMA) polymer. A large film was prepared using the polymer solution containing the complex. The polymer film was then cut into circular sources, mounted on a source holder and supplied to various users.
Nuclear medicine and …, Jan 1, 2010
Introduction: A novel two-step separation process for the production of no-carrier-added (NCA) 17... more Introduction: A novel two-step separation process for the production of no-carrier-added (NCA) 177 Lu from neutron irradiated Yb target through an electrochemical pathway employing mercury-pool cathode has been developed. Methods: A two-cycle electrolysis procedure was adopted for separation of 177 Lu from 177 Lu/Yb mixture in lithium citrate medium. The influence of different experimental parameters on the separation process was investigated and optimized for the quantitative deposition of Yb in presence of 177 Lu. The first electrolysis was performed for 50 min in the 177 Lu/Yb feed solution at pH 6 applying a potential of 8 V using platinum electrode as anode and mercury as the cathode. The second electrolysis was performed under the same conditions using fresh electrodes. The radionuclidic and chemical purity of 177 Lu was determined by using gamma ray spectrometry and atomic absorption spectrometry. The suitability of 177 Lu for biomedical applications was ascertained by labeling 1,4,7,10-tetraazacyclododecane-1,4,7,10tetraacetic acid D-Phe 1 -Tyr 3 -octreotate(DOTA-TATE) with 177 Lu. Results: This process could provide NCA 177 Lu with N99.99% radionuclidic purity and an overall separation yield of ∼99% was achieved within 3-4 h. The Hg content in the product was determined to be b1 ppm. Radiolabeling yield of N98% was obtained with DOTA-TATE under the optimized reaction conditions. Conclusions: An efficient strategy for the separation of NCA 177 Lu, suitable for biomedical applications, has been developed.
Nuclear medicine and biology, Jan 1, 2010
Introduction: In order to meet the growing demand for 99m Tc and to reduce the reliance on fissio... more Introduction: In order to meet the growing demand for 99m Tc and to reduce the reliance on fission-produced 99 Mo, an electrochemical pathway for accessing 99m Tc through the (n, γ) 99 Mo was explored as a back-up measure and to supplement 99m Tc supply for radiopharmaceuticals application. Methods: 99m Tc from an equilibrium mixture of 99 Mo/ 99m Tc was selectively deposited on a platinum cathode in an electrochemical cell by applying optimal voltage and stripped back again into the 0.9% saline solution. The radiochemical and radionuclidic purity of the product were determined using standard techniques. 99m Tc thus obtained was used for labeling standard ligands such as dimercaptosuccinic acid (DMSA) and ethylene dicysteine (EC), to ascertain the usability. Results: Selective deposition of 99m Tc on the platinum electrode was achieved at a potential of 5 V over a period of 1 h in NaOH electrobath. The overall yield of 99m Tc was N90%, with N99.99% radionuclidic purity and N99% radiochemical purity. The performance of the generator remained consistent over a period of 10 days. The compatibility of the product in the preparation of 99m Tc-labeled formulations such as 99m Tc-DMSA and 99m Tc-EC was found to be satisfactory in terms of high labeling yields (N98%). Conclusion: A novel and attractive method has been developed to obtain highly concentrated 99m Tc, without using fission-produced 99 Mo.
Chromatographia, Jan 1, 2009
Currently, 188 Re is obtained from 188 W/ 188 Re chromatographic generator containing alumina whi... more Currently, 188 Re is obtained from 188 W/ 188 Re chromatographic generator containing alumina which has a limited capacity (*80 mg Wg -1 ) for 188 W. This results in high bolus volumes of 188 Re, which often needs to be concentrated before radiolabeling. We have demonstrated the feasibility of using polymer embedded nano crystalline titania (TiP), a novel high capacity sorbent material (*300 mg Wg -1 ), for developing a 188 W/ 188 Re chromatographic generator. A TiP based chromatographic 188 W/ 188 Re generator was developed in which 188 Re could be eluted with 0.9% saline solution. About 90% of the 188 Re could be recovered in the first 4-5 mL of total activity with more than 80% yield. The purity of 188 Re is adequate for clinical applications.
Radiochimica …, Jan 1, 2009
Abstract Rhenium-188 is a well recognized therapeutic radionuclide and its use in a variety of ap... more Abstract Rhenium-188 is a well recognized therapeutic radionuclide and its use in a variety of applications has been reported. The current methods of obtaining no-carrier added 188Re from conventional alumina based generators require 188W of very high specific ...