Authors:M. Mallah, F. Shemirani, and M. Ghannadi Maragheh
A new preconcetration method of dispersive liquid-liquid microextraction (DLLME) was developed for simultaneous preconcentration
of samarium, europium, gadolinium and dysprosium. DLLME technique was successfully used as a sample preparation method. In
this preconcentration method, an appropriate mixture of extraction solvent, disperser solvent was injected rapidly into an
aqueous solution containing Sm, Eu, Gd and Dy after complex formation using chelating reagent of the 1-(2-pyridylazo)-2-naphthol
(PAN). After phase separation, 0.5 mL of the settled phase containing enriched analytes was determined by inductively coupled
plasma optical emission spectrometry (ICP-OES). The main factors affected the preconcentration of Sm, Eu, Gd and Dy were extraction
and dispersive solvent type and their volume, extraction time, volume of chelating agent (PAN), centrifuge speed and drying
temperature of the samples. Under the best operating condition simultaneous preconcentration factors of 80, 100, 103 and 78
were obtained for Sm, Eu, Gd and Dy, respectively.
Authors:H. Faghihian, M. Ghannadi Maragheh, and A. Malekpour
Two natural zeolites from Iranian deposits (clinoptilolite and natrolite) were characterized and their ability for adsorption of iodide from nuclear wastewaters was evaluated. The adsorption behavior was studied on natural and modified zeolites by g-spectrometry using 131I as radiotracer. Adsorption isotherms and distribution coefficient (Kd) were measured. The results showed that clinoptilolite is a more promising zeolite for removal of iodide compared to natrolite. Furthermore, the adsorption was higher in silver, lead and thallium forms, whereas the lowest desorption was observed in lead modified zeolite.
Authors:M. Mallah, M. Ghannadi Maragheh, A. Badiei, and R. Habibzadeh Sbo
In the present work, results of γ-irradiation on normal and functionalized SBA-15 by aurintricarboxylic acid have been reported.
Characterization of normal and functionalized SBA-15 particles before and after γ-irradiation was carried out using Fourier-transform
infrared technique. Aurintricarboxylic acid ligand connected to SBA-15 was also analyzed using UV/Vis spectrophotometer. The
modified sorbent was then used as a new sorbent for separation of trace amounts of praseodymium and lutetium ions from nuclear
waste waters in batch techniques. Based on the results of distribution coefficients determination, and investigation of sorption
process in various conditions, the parameters were optimized for separation lanthanides. It can be concluded that the functionalized
SBA-15 is a promising sorbent for praseodymium and lutetium cations.
Authors:S. Shirmardi, M. Gandomkar, M. Mazidi, M. Shafiei, and M. Ghannadi Maragheh
Tumors such as prostate, small cell lung cancer, breast, gastric and colon cancer are known to overexpress receptors to bombesin
(BBN). In this study, a new bombesin analogue was labeled with 99mTc via HYNIC and tricine/EDDA as coligands and investigated further. HYNIC-GABA-Bombesin (7–14) NH2 was synthesized using a standard Fmoc strategy. Labeling with 99mTc was performed at 100 °C for 10 min and radiochemical analysis involved ITLC and HPLC methods. The stability of radiopeptide
was checked in the presence of humane serum at 37 °C up to 24 h. The receptor bound internalization and externalization rates
were studied in GRP receptor expressing PC-3 cells. Biodistribution of radiopeptide was studied in nude mice bearing PC-3
tumor. Labeling yield of >98% was obtained corresponding to a specific activity of ~2.6 MBq/nmol. Peptide conjugate showed
good stability in the presence of human serum. The radioligand showed high and specific internalization into PC-3 cells (14.63 ± 0.41%
at 4 h). In biodistribution studies, a receptor-specific uptake was observed in GRP-receptor-positive organs so that after
4 h the uptakes in mouse tumor and pancreas were 1.31 ± 0.18 and 1.2 ± 0.13% ID/g, respectively.
Authors:M. Tabasi, M. Ghannadi-Maragheh l, M. Shamsaii, and A. R. Khanchi
Separation and purification of 133Xe from acidic solution containing uranium, 99Mo and 131I has been developed. In the first step of this work, uranium pellets were dissolved under pressure (8-15 bar) in 8M nitric acid solution. Then133 Xe and other gases were conducted to activated charcoal cold trap. Final purification of 133Xe from impurities such as NOx, radioiodine and krypton was performed by passing through a molecular sieve preparative chromatographic column using helium as mobile phase. The final recovery of 133Xe from the separation-purification process was higher than 98%. Adsorption-desorption behavior of radioxenon on the charcoal and molecular sieves have also been studied and discussed.
Authors:Y. Yamini, P. Ashtari, A. Khanchi, M. Ghannadi-Maragheh, and M. Shamsipur
A simple and reliable method for the selective extraction and determination of uranium in water using octadecyl-bonded silica
membrane disks modified with bis (2-ethylhexyl) hydrogen phosphate and alpha-spectrometry is described. Extraction efficiency
and influence of sample matrix, optimum amount of extractant, type and minimum amount of organic eluent and flow rates were
evaluated. The limit of detection of the proposed method is 40 ng per 1000 ml. The influence of potential interfering cations
in water samples on the recovery of U(VI) was investigated. The method was successfully applied to the extraction and determination
of uranium in natural water.
Authors:H. Sepehrian, M. Ghannadi-Maragheh, S. Waqif-Husain, R. Yavari, and A. Khanchi
Five different samples of a new sorbent, modified mesoporous cerium(IV) silicate have been prepared with various mole ratios
of Si/Ce and Cetyltrimethylammonium bromide (CTMABr) as template. XRD, nitrogen sorption, SEM, IR, thermogravimetry and sorption
of radionuclides have been studied. Separation of Hg(II)-Th(IV), Hg(II)-Zr(IV) and Rb(I)-Zr(IV) have been developed on columns
of this novel sorbent.