scholarly journals Determination of Cobalt in Seawater Using Neutron Activation Analysis after Preconcentration by Adsorption onto γ-MnO2 Nanomaterial

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Van-Phuc Dinh ◽  
Ngoc-Chung Le ◽  
Ngoc-Tuan Nguyen ◽  
Quang-Thien Tran ◽  
Van-Dong Nguyen ◽  
...  

The γ-MnO2 nanomaterial has been used to adsorb cobalt in the seawater at Phan Thiet City, Binh Thuan Province, Vietnam. Its concentration is determined by using the neutron activation analysis (NAA) method at the Dalat nuclear research reactor. Factors affecting the uptake of cobalt on the γ-MnO2 material such as the pH, adsorption time, and initial cobalt(II) concentration are investigated. The irradiated experiment data are calculated using the K0-Dalat program. The results obtained show that the trace dissolved cobalt in Phan Thiet seawater is found equal to 0.25 ± 0.04 μg/L (n=5, P=95%) with the adsorption efficiency being higher than 95% (n=4, P=95%).

2015 ◽  
Vol 5 (4) ◽  
pp. 23-29
Author(s):  
Thi Sy Nguyen ◽  
Manh Dung Ho ◽  
Van Doanh Ho ◽  
Quang Thien Tran ◽  
Sam Chung Yong

The k0-based neutron activation analysis (k0-NAA) has been applied for determination of trace multi-element in 5 fruits: Orange, tomato, persimmon, pear and apple. The samples were collected in Vietnam and Korea, and dried-frozen in laboratory at a temperature of -650C, weighed approximately 50 mg or 100 mg each sample, and put in clean polyethylene bags for short and long time irradiations, respectively. The NIST-1547 (Peach Leaves) and IAEA-V-10 (Hay Powder) were used for the purpose of quality control. Both analytical and standard samples were irradiated in the 500 kW Dalat research reactor (Vietnam) and the 20 MW HANARO research reactor (Korea). Concentration of 16 elements: Al, As, Au, Br, Ca, Cl, Co, Eu, Fe, K, La, Mg, Mn, Na, Rb and Zn were determined. By comparison the concentrations of trace elements in the investigated Vietnam and Korea’s fruits, revealed that they are mostly similar between two places. However, the Ca concentration in orange from Vietnam was approximately 2.5 times higher than that one from Korea, whereas the Ca concentration in pear from Vietnam was approximately 21 times lower than that one from Korea. The Mn concentrations in all of fruits that collected in Vietnam were mostly higher than those collected in Korea, ranging between 1.4 to 2.2 times.


2014 ◽  
Vol 4 (1) ◽  
pp. 84-90
Author(s):  
V. Doanh H. ◽  
D. Vu C. ◽  
Q. Thien T. ◽  
N. Son P. ◽  
T. Sy N. ◽  
...  

An auto-pneumatic transfer system has been installed at the Dalat research reactor for rapid instrument neutron activation analysis based on very short-lived nuclides. This system can be used to perform short irradiations in seconds either in the vertical channel 13-2 or in the horizontal thermal column of the reactor. The transferring time of sample from irradiation to measurement position is approximately 3.2 seconds. A loss-free counting system using HPGE detector has been also setup in compacting with the pneumatic transfer system for measurement of sample’s activity, automatically starting for data acquisition at irradiated sample’s arrival. This new facility was tested and shown to have high potential for the determination of short-lived nuclides with half-lives from 10 ¸ 100 seconds. This work presents the results of timing parameter measurements, characterization of irradiation facilities, and application of this system to determining Selenium concentration in several biological reference materials.


2016 ◽  
Vol 19 (4) ◽  
pp. 147-153
Author(s):  
Son An Nguyen ◽  
Tien Van Dang ◽  
Thang Huu Ho ◽  
Hieu Bao Quoc Phan

Neutron beam diameter is a very important parameter in the experimental nuclear research. Determination of the correct neutron beam diameter is the best method to prepare corectly the optimal sample size correctly, reduced data analysis errors. To measure the neutron diameter, some methods were used: Simulation by Monte – Carlo method, neutron image, and neutron activation analysis. In this report, we determined the neutron beam diameter of the 3rd horizontal channel of the Dalat nuclear reactor that activated gold foils. The result shows that this method offer quick and more correct results than other methods which had been published preiously [1, 2].


2021 ◽  
Vol 9 (1A) ◽  
Author(s):  
João Pedro Oliveira Flores ◽  
Paulo Sérgio Cardoso Silva ◽  
Mauro Silva Dias ◽  
Marina Fallone Koskinas ◽  
Denise Simões Moreira ◽  
...  

The short irradiation facility of the IEA-R1 nuclear research reactor at IPEN, São Paulo,  Brazil, has been used for short irradiation of samples for the purpose of determining the concentration of elements of these samples through the use of the instrumental neutron activation analysis technique. With the aim of implementing the k0-NAA method at the Neutron Activation Analysis Laboratory (LAN), the reactor parameters a and f were obtained using the bare triple method. In this method, a set of three neutron flux monitors were irradiated without Cd-cover. The efficiency curve of the gamma-ray spectrometer used was determined by measuring calibrated radioactive sources at the commonly used counting geometries. The results for the parameters a and f were respectively 0.0384±0.0016 and 35.67±0.26. This value of f shows that the neutrons in the irradiation position are well thermalized.The variation of these parameters was studied with time and the reproducibility was verified.  


2014 ◽  
Vol 4 (3) ◽  
pp. 36-42
Author(s):  
Van Doanh Ho ◽  
Quang Thien Tran ◽  
Thi Sy Nguyen ◽  
Nhi Dien Nguyen

A rapid neutron activation analysis technique for determination of the concentration of selenium in biological materials using short-lived radionuclide 77mSe (half-life = 17.4 seconds) has been developed at Dalat Nuclear Research Institute (DNRI). The technique is very simple and rapid. It involves irradiation of a sample for 20 s, decay for 20 s and counting for 20 s. The accuracy of the method has been evaluated by analyzing a number of biological standard reference materials of varied selenium levels. An agreement between measured and certified values was acceptable in regarding to the deviation of the above mentioned two values within 8 percent. The result shows that the utilization of short-lived radionuclide 77mSe is more useful in comparison with long-lived radionuclide 75Se (half-life = 120 days). In addition, it is suggested that a further study for cyclic irradiations should be done in order to enhance the detection limit of the determination of the short-lived radionuclide 77mSe.


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