Duration Of Equilibration Research Articles

Specifics of vitrification of in vitro-produced cattle embyos at various development stages

Producing embryos in vitro is an important technology used to improve the genetic potential of cattle and perfect the programs of their breeding. Regardless of the way they are produced, all embryos that had not been used for transplantation to recipients must be conserved. Because of significantly increased interest in the problem of cryoconservation of embryos, both coming from scientists and businesses, there are emerging new commercial environments that allow the facilitation of cryoconservation and the increase in the embryo survival. Oocyte-cumulus complexes obtained from the ovaries of slaughtered clinically healthy cows matured in 22–24 h in in vitro conditions. The oocytes were co-cultured with spermatozoids in Fertilization medium, and the obtained zygotes were cultured in Culture medium with Sodium-Pyruvate for 4 or 7 days up to the stage of morula or blastocyste, respectively. For the vitrification of cow embryos, we used a commercial kit for the vitrification of human embryos, having compared the duration of equilibration. According to the results of the studies, we observed high efficiency of cryoconservation of cow embryos using the commercial kit for vitrification of human embryos. The results revealed the significant effect of equilibration on survival and further development of embryos. In addition, we described the dependence of development stage of cattle embryo on the duration of the contact of embryo with equilibration solution. Therefore, optimal time of contact of cattle embryos at the morula stage with equilibration solution was 12 minutes. On the 24th h after thawing, 46.7 ± 3.3% of the embryos were observed to undergo blastulation, and on 48th h, this parameter increased to 96.7 ± 3.3%, which corresponded to the parameters in the group of embryos that had not been subjected to cryoconservation. In the conditions of further cultivation, the percentage of blastocystes that hatched in the experimental group was no different from that of the control. At the same time, the highest efficiency of vitrification of blastocystes of cows was seen after the contact with the equilibration solution for 15 min, since the percentage of hatched blastocystes was the same as in the control group. Therefore, using the commercial kit for vitrification of human embryos is beneficial, for it promotes the parameters of cow embryos after vitrification/thawing that are similar to such of intact embryos (without freezing). The data we analyzed and presented in the paper could help to increase the efficiency of cryoconservation of cattle embryos for both scientific and commercial purposes.

Impact of equilibration duration combined with temperature on the outcome of bovine oocyte vitrification

The cryopreservation of mammalian oocytes and embryos has become an integral part of assisted reproduction in both humans and veterinary species. However, the methods used to cryopreserve bovine oocytes still have significant shortcomings. A wide variety of approaches has been used to try to improve and optimize methods of cryopreservation. However, these procedures employed are not always designed to specifically take account of the osmotic tolerance response of the cells according to the temperature and time of cryoprotectant (CPA) addition. When these properties are considered, optimal procedures for the addition of CPAs can be designed proactively. Based on in silico and in vitro osmotic observations, we propose shorter dehydration-based protocols at different temperatures (25°C vs. 38.5°C) towards defining an improved cryopreservation method. In vitro matured oocytes were exposed to equilibration solution (ES) at 25°C and 38.5°C and effects of optimized exposure times for each temperature were determined prior to vitrification/warming on oocyte spindle configuration, DNA fragmentation, and further embryo development. Upon exposure to standard ES (7.5% dimethyl sulfoxide + 7.5% ethylene glycol in TCM199 medium + 20% fetal bovine serum), original oocyte volume was recovered within 2 min 30 s at 38.5°C and 5 min 30 s at 25°C. In vitro matured oocytes were then exposed to the aforementioned cryoprotectants at both temperature/duration conditions and vitrified/warmed. While similar percentages of oocytes exhibiting a normally configured spindle and DNA fragmentation were observed in the fresh control group and oocytes vitrified at 38.5°C, significantly higher apoptosis rate and lower percentages of normal spindle configuration were observed in oocytes vitrified at 25°C when compared to control fresh oocytes. Similar cleavage rates and blastocyst yields were observed in the vitrified/38.5°C and fresh controls, while these rates were lower in vitrified/25°C. These results revealed that the limitation of the exposure time of the oocytes to the ES to the point of osmotic equilibrium volume recovery could be a more efficient approach to prepare them for vitrification. Therefore, exposure time to ES to 2 min 30 s at 38.5 °C appears to improve the quality of vitrified/warmed oocytes by protecting spindle integrity and reducing DNA fragmentation thus improving blastocyst rates and embryo quality.

Adsorption of uranium by diethylenetriamine functionalized magnetic mesoporous silica

The iron oxide (Fe3O4) embedded mesoporous silica was prepared and functionalized with diethylenetriamine (DETA) functional groups for the separation of uranium from aqueous medium. The prepared product was abbreviated as Fe-MCM-DETA. The Fe-MCM-DETA was characterized by Raman spectroscopy, particle size distribution, X-ray diffraction, BET surface area, BJH pore size distribution, thermogravimetry, FT-IR, scanning electron microscopy, and transmission electron microscopy. The adsorption of uranium on Fe-MCM-DETA was evaluated as a function of various aqueous phase parameters such as pH, duration of equilibration, concentration of uranium in the aqueous phase, and presence of interfering ions. The adsorption of uranium on Fe-MCM-DETA followed the second-order rate equation. The maximum adsorption capacity of uranium was determined to be ∼470 mg.g−1 at pH 6 by Langmuir adsorption isotherm modeling. The results obtained from adsorption studies and the physical properties of Fe-MCM-DETA were compared with DETA functionalized on Fe3O4 (Fe-DETA), silica gel (Si-DETA), and mesoporous silica (MCM-DETA). The uranium loaded on Fe-MCM-DETA was retrieved using Na2CO3 solution, the feasibility for recycling of Fe-MCM-DETA without much loss of adsorption capacity was studied, and the results are reported in this paper.

Me2SO perfusion time for whole-organ cryopreservation can be shortened: Results of micro-computed tomography monitoring during Me2SO perfusion of rat hearts.

Cryopreservation of whole organs and specific tissues is an important and continually expanding field of medicine. The protocols currently used for organ preservation do not ensure survivability and functionality; the protocols for ovarian tissue lead to acceptable outcomes, but these are still capable of further improvement. In general, cryopreservation protocols need to be optimized. One important approach to improving cryopreservation protocols in general involves reducing exposure to cytotoxic cryoprotective agents prior to freezing. This study, therefore, evaluated the real-time tissue penetration of dimethyl sulfoxide, a cryoprotective agent that is widely used in cryopreservation. Dimethyl sulfoxide penetration in rat hearts perfused with a 15% (v/v) dimethyl sulfoxide solution was examined in real-time using dynamic contrast-enhanced micro-computed tomography imaging. Viability of cardiomyocytes was not significantly affected by the dimethyl sulfoxide perfusion procedure. Two different perfusion rates were evaluated and compared with perfusion using a common iodine-based contrast agent (iomeprol). The dynamic contrast-enhanced micro-computed tomography imaging data showed that dimethyl sulfoxide flushes both the extracellular and intracellular spaces in rat heart tissue to 95% equilibration after ≈ 35 s via perfusion. Subsequent wash-out via perfusion is completed to 95% within ≈ 49 s. The equilibration duration routinely used in dimethyl sulfoxide–based protocols for cryopreservation should therefore be questioned. Shorter incubation duration would perhaps be sufficient, as well as being beneficial in relation to cell survivability. It would be helpful to have techniques for non-invasive real-time monitoring of the penetration of cryoprotective agents and such techniques should be used to revise cryopreservation protocols. Switching to perfusion-based equilibration procedures might be beneficial, if feasible.

High capacity amidic succinic acid functionalized mesoporous silica for the adsorption of uranium

The nuclear reactors operating worldwide are currently using the uranium mined from the resources available on the earth's crust. A significant volume of aqueous waste containing a small quantity of uranium was generated during the processing of ores. There is a growing demand to remove this toxic uranium from these aqueous streams, owing to the limit of tolerable daily intake (15 μg L−1) for uranium imposed by the World Health Organization. This demand throws huge challenges to the separation chemists to engineer the solid phase adsorbents having high capacity, excellent selectivity and satisfactory throughputs for processing a vast quantity of aqueous waste containing traces of uranium. In this context, the task specific amidic succinic acid (SUC) functional groups tailored on mesoporous silica having wide porosity and large surface area have been prepared and characterized by BET surface area, pore and particle size distribution, thermogravimetry, SEM-EDX analysis, FT-IR and Raman spectroscopy. The adsorption behavior of uranium (VI) from the aqueous phase on the tailored adsorbent (MCM-SUC) was studied as a function of pH of the aqueous phase, duration of equilibration, uranium concentration in the aqueous phase, and the results were compared with the adsorbent containing the same functional group but grafted on silica gel (Si-SUC), which exhibited adsorption capacity of 61 mg g−1. The fast kinetics of adsorption and significantly high Langmuir adsorption capacity of uranium (807 mgg −1), as compared to the other mesoporous adsorbents reported in literature, achieved in MCM-SUC was due to controlled synthesis of SUC functionalized mesoporous silica that favoured high degree of SUC number density on the mesoporous material. The adsorbed uranium was recovered using 0.1 M nitric acid.

Diethylenetriamine tethered mesoporous silica for the sequestration of uranium from aqueous solution and seawater

Mesoporous silica (MCM-41) with large surface area and porosity has been synthesized and tethered covalently with the uranium (VI) specific ligand, namely diethylenetriamine (DETA) on MCM-41. The adsorbent, abbreviated as MCM-DETA, was characterized by BET surface area, BJH pore size and particle size distribution, thermogravimetry, SEM-EDX analysis, and FT-IR spectroscopy, and studied for the adsorption of uranium from aqueous solution. The parameters evaluated were the effect of pH of the aqueous phase, duration of equilibration, concentration of uranium in the aqueous phase, and the effect of interfering ions on the adsorption of uranium (VI) on MCM-DETA. The adsorption behavior of uranium from seawater (U(VI) = 10 mg.L−1) was studied by batch equilibration method. The results revealed that MCM-DETA showed rapid adsorption kinetics (k2 = 2.85 × 10-3 mol.L−1. min−1), extremely large Langmuir adsorption capacity (1067 mg.g−1), good selectivity over other interfering ions, and efficient adsorption of uranium from seawater (680 mg.g−1) spiked with uranium, indicating that MCM-DETA a promising candidate for the adsorption of uranium from aqueous solution and seawater.

Selective separation of zirconium(IV) from uranium(VI) using dioxoamide ligand present in ammonium based ionic liquid: An application towards spent metallic fuel reprocessing

The alloy of an actinide (U or Pu) with zirconium (6%) has been proposed as metallic fuel. The removal of zirconium from the dissolver solution is required prior to the separation of actinides during reprocessing. In this context, the extraction behavior of zirconium was studied in a solution of 2-ethylhexyl- and the decyl-derivative of benzodioxodiamide, abbreviated as BD and BDD, respectively, in ionic liquid medium. Instead of the conventional imidazolium ionic liquid that displayed several drawbacks, strongly hydrophobic ionic liquids such as methyltributylammonium bis(trifluoromethylsulfonyl)imide ([N1444][NTf2]) and methyltrioctylammonium bis(trifluoro-methylsulfonyl)imide ([N1888][NTf2]) have been employed, as a diluent, in conjunction with the BD and BDD ligands for the extraction of Zr(IV). The effect of nitric acid concentration in aqueous phase, duration of equilibration, interference of uranium and the effect of temperature on the extraction of Zr(IV) in BD present in ionic liquid was studied. The number of BD-ligands involved in the extraction of zirconium was determined. The results showed the possibility of removing zirconium from the bulk quantity of uranium present in the dissolver solution.

Preparation and ion exchange studies of cesium and strontium on sodium iron titanate

Sodium iron titanate (NaFeTiO) inorganic ion exchanger was synthesized and the ion exchange behaviour of cesium, strontium and europium ion on NaFeTiO was studied. The sodium iron titanate was prepared by the hydrolysis of tetraethyl ortho titanate with sodium hydroxide in the presence of ferric chloride at the Ti/Fe mole ratio of 25.7. The ion exchange material was characterized by elemental analysis, sodium exchange capacity, X-Ray diffraction, thermogravimetry, and Raman spectroscopy. The distribution coefficient (Kd, mL/g) of cesium, strontium and europium on NaFeTiO was measured as a function of pH of the aqueous phase, duration of equilibration, concentration of sodium, cesium, strontium and europium ion in aqueous phase. The Kd of cesium gradually increased with increase of pH, and that of strontium also increased up to pH 6 followed by saturation in Kd values. However, the distribution coefficient of europium increased up to pH 4 followed by the precipitation of europium at higher pH values. The rate of ion exchange of cesium and strontium on NaFeTiO was rapid in the initial stages of equilibration followed by the establishment of equilibrium occurring after 200 min. The kinetics of extraction was fitted in to pseudo-first order and -pseudo-second order rate equations. The NaFeTiO was found to follow the ion exchange mechanism, in which the sodium ion from NaFeTiO was exchanged with cesium or strontium ion from aqueous phase. The strontium exchange capacity on NaFeTiO was determined to be 233 mg g−1. The loaded metal ions was recovered using 0.5 M nitric acid.

Impact of equilibration duration during oocyte vitrification protocol: preliminary results of a prospective observational study

Impact of equilibration duration during oocyte vitrification protocol: preliminary results of a prospective observational study

Sequestration of U(VI) from aqueous phase using diethylenetriamine anchored polystyrene-divinylbenzene copolymer

Abstract Diethylenetriamine (DETA) moiety was chemically anchored on polystyrene-divinylbenzene (PS-DVB) co-polymer, and the resultant resin (PS-DETA) was studied for the extraction of uranium from aqueous solution. The extraction behavior of U(VI) was studied in PS-DETA a function of duration of equilibration, pH of the feed solution, concentration of U(VI), CO 3 2 − , Fe2＋, Co 2 + and Ni 2 + ions. The rate of extraction of uranium in PS-DETA was fitted into pseudo-first order and pseudo-second order rate equations. The extraction isotherm of uranium was fitted to Langmuir adsorption model. Recycling option of the resin PS-DETA was studied by subjecting the resin to repeated extraction and back-extraction of uranium. The performance of PS-DETA under the dynamic condition was evaluated by following the breakthrough curve of uranium. The extracted uranium was quantitatively recovered by using dilute nitric acid.

Amidic succinic acid moiety anchored silica gel for the extraction of UO22+ from aqueous medium and simulated sea water

A solid phase adsorbent containing amidic carboxylic acid functional group on the surface of the silica gel was prepared by organo-surface modification reactions and characterized the product, Si-SUC, by FT-IR, Raman, thermogravimetry, X-ray diffraction, SEM-EDX and pH titration techniques. The extraction behaviour of U(VI) from aqueous solution was studied as a function of various parameters such as the aqueous phase pH, duration of equilibration, presence of interfering ions and concentration of U(VI) in aqueous phase to evaluate the feasibility using Si-SUC for the recovery of U(VI) from sea water. The kinetic data on the extraction of U(VI) was fitted into second order rate equation, and the U(VI) extraction isotherm was fitted using Langmuir, Freundlich, Dubinin- Radushkevich and Temkin adsorption models. The performance of Si-SUC was evaluated under dynamic conditions by following a break-through behaviour of U(VI) in the column study. The effect of flow-rate and concentration of U(VI) in the feed solution, on the break-through behaviour of U(VI) was studied and fitted the breakthrough curve using Thomas model.

Studies on the uptake of Am(III) and Eu(III) on ionic liquid modified polystyrene-divinyl benzene

Abstract Imidazolium bis(2-ethylhexyl)phosphate ionic liquid was anchored on a polystyrene-divinylbenzene (PS-DVB) copolymer and the product (R-Im-DEHP) was studied for the extraction of Am(III) and Eu(III) from dilute nitric acid medium to examine the feasibility using the anchored adsorbent for their mutual separation. The effect of various parameters such as the duration of equilibration, concentration of nitric acid, europium ion, and diethylenetriaminepentaacetic acid (DTPA) in aqueous phase on the distribution coefficient (K d) of Am(III) and Eu(III) was studied. The distribution coefficient of Am(III) and Eu(III) decreased with increase in the concentration of nitric acid. Rapid extraction of metal ions in the initial stages of equilibration followed by the establishment of equilibrium occurred within 4 h. The data on the rate of uptake of Am(III) and Eu(III) were fitted into pseudo-first order and pseudo-second order rate equation. The extraction isotherm was fitted to Langmuir and Freundlich adsorption models and the apparent europium extraction capacity was determined. The mechanism of extraction was elucidated and the conditions needed for efficient separation of Am(III) from Eu(III) was optimized using DTPA. The study indicated the possibility of using R-Im-DEHP for the separation of Eu(III) from Am(III) with high separation factors.

A magnetic adsorbent for the mutual separation of Am(III) and Eu(III) from dilute nitric acid medium

Iron oxide (Fe3O4) particles anchored with 1-butyl-3-methylimidazolium bis(2-ethylhexyl)diglycolamate (Fe–Si-MeIm-DEHDGA) was synthesized and characterized by X-ray diffraction, Raman spectroscopy and scanning electron microscopy (SEM) etc. The adsorption behavior of Am(III) and Eu(III) in Fe–Si-MeIm-DEHDGA was studied from dilute nitric acid medium to examine the feasibility of using Fe–Si-MeIm-DEHDGA for the magnetic assisted mutual separation of trivalent actinides and lanthanides. The effect of various parameters such as the duration of equilibration, concentration of nitric acid and diethylenetriaminepentaacetic acid (DTPA) in aqueous phase on the distribution coefficient (Kd) of Am(III) and Eu(III) was studied. The distribution coefficient of ~104mL/g was obtained for both Am(III) and Eu(III) at pH3 and it decreased with increase in the concentration of nitric acid. Rapid adsorption of metal ions in the initial stages of equilibration followed by the establishment of equilibrium occurred within 2h. The study indicated the possibility of using Fe–Si-MeIm-DEHDGA particles for the magnetic separation of Eu(III) from Am(III) with high separation factors.

Comparison in the extraction properties of Pu(IV) in piperidinium and pyrrolidinium nitrate anchored anion exchange resins

Abstract Piperidinium nitrate (Pip − NO3) and pyrrolidinium nitrate (Pyr − NO3) functional groups were anchored on a poly(styrene-divinylbenzene) matrix and evaluated the resultant anion exchange resin for the extraction of plutonium from nitric acid medium. The distribution coefficient (K d, mL/g) of Pu(IV) in these resins increased with the concentration of nitric acid, reaching a maximum K d at 7 M nitric acid, followed by decrease. The extraction of Pu(IV) increased with the duration of equilibration followed by the establishment of equilibrium, occurred within four hours of equilibration. The kinetic data were fitted with pseudo-first order and pseudo-second order rate equations. The apparent plutonium exchange capacity was determined to be ∼256 mg/g for Pip − NO3 resin and 285 mg/g for Pyr − NO3 resin at 7 M nitric acid. The radiolytic degradation of Pip − NO3 and Pyr − NO3 in presence of nitric acid (7 M) was studied upto a dose of 200 KGy and the results are reported in this paper.

Diglycolamic acid anchored on polyamine matrix for the mutual separation of Eu(III) and Am(III)

Abstract Diglycolamic acid was anchored on a polyamine matrix and the product (PA-DGAH) was characterized by ion-exchange capacity measurement, TG-DTA and FT-IR spectroscopy. The extraction behavior of Am(III) and Eu(III) in PA-DGAH was studied from dilute nitric acid medium to examine the feasibility using the anchored adsorbent for their mutual separation. The effect of various parameters such as the duration of equilibration, concentration of europium, nitric acid and diethylenetriaminepentaacetic acid (DTPA) in aqueous phase on the distribution coefficient (K d) of Am(III) and Eu(III) was studied. The distribution coefficient decreased with increase in the concentration of nitric acid. Rapid extraction of metal ions in the initial stages of equilibration followed by the establishment of equilibrium occurred within 4 h. The data on the rate of uptake of Am(III) and Eu(III) were fitted into pseudo-first order and pseudo-second order rate equation. The extraction isotherm was fitted to Langmuir and Freundlich adsorption models and the apparent europium extraction capacity was determined. The mechanism of extraction was elucidated and the conditions needed for efficient separation of Am(III) from Eu(III) was optimized using DTPA. The study indicated the possibility of using PA-DGAH for the separation of Eu(III) from Am(III) with high separation factors.

Novel Diglycolamic Acid Functionalized Iron Oxide Particles for the Mutual Separation of Eu(III) and Am(III)

Iron oxide (Fe3O4) particles functionalized with diglycolamic acid (Fe-DGAH) were synthesized and characterized by TG-DTA, X-Ray diffraction,1H NMR, and scanning electron microscopy (SEM). The extraction behavior of Am(III) and Eu(III) in Fe-DGAH was studied from dilute nitric acid medium to examine the feasibility for the mutual separation of trivalent actinides and lanthanides using Fe-DGAH. For this purpose, the effect of various parameters such as the duration of equilibration and concentrations of europium, nitric acid, and diethylenetriaminepentaacetic acid (DTPA) in the aqueous phase on the distribution ratio (Kd) of Am(III) and Eu(III) was studied. The conditions needed for the efficient separation of Am(III) from Eu(III) were optimized using DTPA. The distribution ratio of ˜104 mL/g was obtained for both Am(III) and Eu(III) at pH 3, and it decreased with an increase in the concentration of nitric acid. However, a separation factor of Eu(III) over Am(III) of ˜150 was achieved in the presence of DTPA. Rapid sorption of metal ions in the initial stages of equilibration followed by the establishment of equilibrium occurred within 2 h. The sorption data were fitted to the Langmuir adsorption model, and the apparent europium sorption capacity was determined to be ˜50 mg/g. The study indicated the feasibility of using Fe-DGAH particles for magnetic separation of Eu(III) from Am(III) with high separation factors.

Extraction Behavior of Americium(III) in Benzoylpyrazolone Dissolved in Pyrrolidinium Based Ionic Liquid

Extraction of Am(III) from nitric acid medium was carried out in a solution of benzoylpyrazolone (HPMBP) dissolved in 1-butyl-1-methylpyrrolidinium bis(trifluoro-methanesulfonyl)imide ([C4mpyr][NTf2]) ionic liquid. The extraction behavior of Am(III) in ionic liquid phase was investigated as a function of various parameters, such as pH of aqueous phase, duration of equilibration, and concentration of ionic liquid and nitrate in aqueous phase. Appreciable extraction was obtained at low pH medium (< pH 2) unlike other diketone based extractant. Extraction of Am(III) in ionic liquid was compared with that observed in a molecular diluent, n-dodecane (n-DD) under similar experimental condition. Remarkably high distribution ratio was observed in IL medium as compared to n-DD medium. The slope analysis of the extraction data was carried out to evaluate the mechanistic aspects of extraction. Extraction mechanism was different from conventional molecular diluent. Recovery of americium from the loaded ionic liquid phase was also studied using nitric acid.

Magnetic Assisted Separation of Trivalent F- Elements from Dilute Nitric Acid Medium

The thio glycolamic acid functional groups were chemically anchored on magnetic iron oxide (Fe3O4) particles and it was characterized by TG-DTA, XRD, and scanning electron microscopy. The extraction behavior of hazardous Am(III) and Eu(III) from dilute nitric acid medium in the sorbent (abbreviated as Fe-SDGAH) was studied. The effect of various parameters such as the duration of equilibration, and concentrations of nitric acid and europium ion in aqueous phase on the distribution coefficient (Kd) of Am(III) and Eu(III) was studied. The studies indicated the possibility of using Fe-SDGAH particles for magnetic separation of Eu(III) and Am(III) with high decontamination factors.

A new 2-oxy-N,N-dioctylacetamide grafted resin for the separation of trivalent actinides from nitric acid medium

Abstract A novel 2-oxy-N,N-dioctylacetamide anchored on Merrifield resin was synthesized and characterized by elemental analysis, TG-DTA and IR spectroscopy, for the first time. The extraction behavior of Am(III) and Eu(III) from nitric acid medium in the dioctylacetamide anchored resin (R-DOA) was studied as a function of various parameters such as duration of equilibration, concentration of nitric acid and sodium nitrate etc. The distribution coefficient (K d) of Am(III) and Eu(III) in R-DOA increased with increase in concentration of nitric acid. The K d values reached a maximum at 3–4 M nitric acid concentration in both cases, followed by decrease in K d values. Rapid extraction of Am(III) and Eu(III) from nitric acid medium was observed in the initial stages of equilibration followed by the establishment of equilibrium occurred within 60 min. The extraction data was fitted in to the first order rate equation. The recovery of Am(III) and Eu(III) from the loaded organic phase was studied using dilute nitric acid. The results revealed that 2-oxyacetamide functionalized resin is the promising candidate for the separation of trivalent actinides and lanthanides from nitric acid medium.

Diglycolamic acid modified silica gel for the separation of hazardous trivalent metal ions from aqueous solution

The surface of the silica gel was modified with diglycolamic acid moieties and the product (Si-DGAH) was characterized by elemental analysis, TG–DTA, 1H and 29Si NMR and scanning electron microscopy (SEM). The adsorption behavior of hazardous americium (III) and europium (III) in Si-DGAH was studied from aqueous nitric acid medium to examine the feasibility using the modified silica for the separation of Am(III) and Eu(III) from aqueous wastes. In this context, the effect of various parameters such as the duration of equilibration, and concentrations of europium, nitric acid, sodium nitrate and diethylenetriaminepentaacetic acid (DTPA) in aqueous phase, on the distribution coefficient (Kd) of Am(III) and Eu(III) was investigated. The distribution coefficient of ∼103mL/g (>99.9% extraction) was obtained for both Am(III) and Eu(III) at pH 3, and the Kd values decreased with increase in the concentration of nitric acid. Rapid kinetics of extraction in the initial stages of equilibration, followed by the establishment of equilibrium occurred within 30min. The extraction data were fitted into Langmuir adsorption model and the apparent europium extraction capacity was determined. Europium loading capacity of the sorbent was determined at various feed pH by column method. The study indicated the possibility of using diglycolamic acid-modified silica for the separation of Eu(III) and Am(III) from aqueous wastes.