Search Results

You are looking at 1 - 10 of 72 items for

  • Author or Editor: Z. Turel x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

Neutron activation analysis has become one of the most sensitive and selective analytical technique for the determination of trace elements in a wide variety of matrices. Neutron activation involves the irradiation of the test sample and a standard of the element to be determined with thermal neutrons in a reactor, followed by dissolution of the test sample in the presence of carrier of the element to be determined. The carrier and radioisotopes are separated from the bulk of other induced activities (employing precipitation, solvent extraction, ion exchange etc.) and then the activity induced in the sample is measured on a suitable detector. The standard is treated identically. From the ratios of the activity of the sample and standard and the weight of the standard irradiated, the concentration of element in the test sample is calculated. A rapid, selective and sensitive method of radiochemical separation is subtoichiometric extraction in which the same amount of carrier is added to the irradiated test sample and standard. Exactly the same amount of reagent is added to both the sample and standard but in substoichiometric amounts, followed by the separation of the species formed by extracting it with an organic solvent. The activities of the extracts are measured. The amount of element present in the sample is calculated with help of the ratio of the activities and the weight of the standard taken. The advantages of the method are discussed. Application of substoichiometry in neutron activation has been elucidated with reference to the determination of Au in various samples by substoichiometric neutron activation analysis.

Restricted access

Abstract  

A method has been developed for the extraction of Au(III) with 2-mercaptobenzimidazole into n-butanol.199Au has been used as a tracer for establishing the ideal extraction parameters such as effect of pH, time of equilibration, solvents and anions. Separation factor and decontamination factor have also been evaluated to determine the selectivity of the method with respect to various elements. The interfering elements were suppressed by the use of suitable masking agents which increased the selectivity. The stoichiometry of metal to reagent was determined by the method of substoichiometric extraction and slope ratio method.

Restricted access

Abstract  

A method has been developed for the determination of elements in normal and diseased tissues of the bone employing radiochemical and instrumental neutron activation analysis. Elements such as Na, Br, Au, Sb, Sc, Fe, Zn and Cr were subjected to irradiation in 252Cf or CIRUS reactor followed by measurement of the activity on a HPGe detector coupled to a PC based MCA unit. Elements such as Co, Ca and P were subjected to radiochemical separation prior to the measurement. The statistical evaluation with respect to accuracy and precision is discussed.

Restricted access

Abstract  

A new and rapid method has been developed for the quantitative extraction of Ru(III) with 2-mercaptobenzimidazole into n-butanol. The extraction coefficient of Ru(III) between n-butanol and an ethanolic solution of 1% 2-mercaptobenzimidazole showed a maximum value ofE=161 at a pH of 2.0. The effect of various other parameters on the extraction coefficient value of Ru(III) such as solvent effect, anions, cations, etc. have also been studied. The stoichiometry of metal to reagent has also been determined by the method of substoichiometric extraction and by the slope ratio method and was found to be 1∶3. Decontamination factor for various elements in the substoichiometric extraction of Ru(III) were also evaluated.

Restricted access

Abstract  

2-mercaptobenzothiazole has been used for the solvent extraction of Os(IV) in acidic medium. The extraction of Os(IV) was found to be better than 90% over the pH range of 3.0 to 5.0 with an equilibration time of 5.0 minutes. The stoichiometry of metal:reagent determined by substoichiometric extraction and slope ratio method was found to be 1∶4. Decontamination factor for various elements in the substoichiometric extraction of Os(IV) were also evaluated.

Restricted access

Abstract  

Quantitative determination of thallium and barium in aquatic environmental samples employing radiochemical neutron activation analysis technique was carried out. Cerium(IV) molybdate was used as an inorganic ion-exchanger. The accuracy, precision and sensitivity of the method was determined. The determination factor of various elements was also evaluated.

Restricted access

Abstract  

A rapid and simple method has been developed for the precipitation of Co(II) with 3,4-diaminobenzophenone. The effect of various parameters as pH, temperature, time of heating, anions and interference of cations have been evaluated. The stoichiometry of the metal to reagent was found to be 1∶2.

Restricted access

Abstract  

Ideal conditions for the extraction of Ir(III) with 2-mercaptobenzothiazole (2-HMBT) into chloroform have been established. The effects of various parameters such as pH, time of equilibration, time of heating, solvents, cation and anion interferences have been studied. The stoichiometry of metal to reagent has been evaluated.

Restricted access

Abstract  

Some macro and micronutrients in soils from some districts of Maharashtra State have been determined by instrumental neutron activation analysis. Neutrons from 252Cf have been used for irradiation. The activity induced was measured by a HPGe detector coupled to a MCA unit. The statistical evaluation of the method has been explained.

Restricted access

Abstract  

A rapid and selective method has been developed for radiochemical separation, and determination of Cs in complex matrices by thermal neutron activation analysis. Batch adsorption of 134Cs was carried out on zirconium phosphate ion exchanger. A large number of samples of the ore have been analysed for their Cs content and the results are discussed.

Restricted access