scholarly journals Proposal to correct for the effect of background and density in the determination of gamma emitters using sodium iodide detectors

2021 ◽  
pp. 14-25
Author(s):  
Ana Milena Velásquez ◽  
Fernando Mosos ◽  
Giovanni Vela
Keyword(s):  
Relative Efficiency ◽  
Sodium Iodide ◽  
Activity Concentration ◽  
Germanium Detector ◽  
General Interest ◽  
Natural Background ◽  
Soil Sediment ◽  
Comparison Of The Results ◽  
Concentration Levels

This study develops a modification to the spectra decomposition method for sodium iodide scintillation equipment, including correcting the natural background counts for the activity concentration calculation. A comparison of the results obtained between two sodium iodide detectors of 2 X 2 in and 3 x 3 in versus a hyper-pure germanium detector of 50 % relative efficiency is performed for soil, sediment, and water samples. It is found that background correction significantly improves activity concentration results in higher energy regions. The concentration values determined by the different spectrometric systems for the samples analyzed do not show significant differences, which supports the results obtained with the proposed calculation method. The uncertainty associated with the measurement and detection limits for the NaI (Tl) detectors is higher than those obtained with the GeHp detector due to the operation of the two technologies and the presence of interferences in the regions of interest. The study carried out in this work establishes an analytical milestone. The methodological model proposed makes it possible to quantify, with reliable results, low concentration levels of NORM materials and even 131I using sodium iodide detectors, among other analytical applications of general interest.

scholarly journals Test spectra experimental construction for evaluating gamma-spectrometry computer codes for the 235U determination

2014 ◽  
Vol 29 (suppl.) ◽  
pp. 1-7 ◽  
Author(s):  
Konstantinos Karfopoulos ◽  
Dimitrios Karangelos ◽  
Marios Anagnostakis ◽  
Simos Simopoulos
Keyword(s):  
Gamma Spectrometry ◽  
Energy Region ◽  
Environmental Samples ◽  
Activity Concentration ◽  
Germanium Detector ◽  
Computer Code ◽  
High Background ◽  
Spectrometry Analysis ◽  
Background Continuum ◽  
Concentration Levels

The determination of 235U in environmental samples from its 185.72 keV photons may require the deconvolution of the multiplet photopeak at ~186 keV, due to the co-existence of the 186.25 keV photons of 226Ra in the spectrum. Successful deconvolution depends on many parameters, such as the detector characteristics, the activity concentration of the 235U and 226Ra in the sample, the background continuum in the 186 keV energy region and the gamma-spectrometry computer code used. In this work two sets of experimental test spectra were constructed for examining the deconvolution of the multiplet photopeak performed by different codes. For the construction of the test spectra, a high-resolution low energy germanium detector was used. The first series consists of 140 spectra and simulates environmental samples containing various activity concentration levels of 235U and 226Ra. The second series consists of 280 spectra and has been derived by adding 137Cs, corresponding to various activity concentration levels, to specific first series test spectra. As the 137Cs backscatter edge is detected in the energy region of the multiplet photopeak at ~186 keV, this second series of test spectra tests the analysis of the multiplet photopeak in high background continuum conditions. The analysis of the test spectra is performed by two different g-spectrometry analysis codes: (a) spectrum unix analysis code, a computer code developed in-house and (b) analysis of germanium detector spectra, a program freely available from the IAEA. The results obtained by the two programs are compared in terms of photopeak detection and photopeak area determination.

scholarly journals Determination of the activity concentration levels of the artificial radionuclide137Cs in soil samples collected from Qatar using high-resolution gamma-ray spectrometry

2016 ◽  
Vol 44 ◽  
pp. 1660237
Author(s):  
Huda Al-Sulaiti ◽  
Tabassum Nasir ◽  
K. S. Al Mugren ◽  
N. Alkhomashi ◽  
N. Al-Dahan ◽  
...  
Keyword(s):  
High Resolution ◽  
Nuclear Power ◽  
Activity Concentration ◽  
Gamma Ray ◽  
Germanium Detector ◽  
Soil Samples ◽  
Gamma Ray Spectrometry ◽  
Activity Concentrations ◽  
High Resolution Gamma

The goal of this study was to establish the first baseline measurements for radioactivity concentration of the artificial radionuclide [Formula: see text]Cs in soil samples collected from the Qatarian peninsula. The work focused on the determination of the activity concentrations levels of man-made radiation in 129 soil samples collected across the landscape of the State of Qatar. All the samples were collected before the most recent accident in Japan, “the 2011 Fukushima Dai-ichi nuclear power plant accident”. The activity concentrations have been measured via high-resolution gamma-ray spectrometry using a hyper-pure germanium detector situated in a low-background environment with a copper inner-plated passive lead shield. A radiological map showing the activity concentrations of [Formula: see text]Cs is presented in this work. The concentration was[Formula: see text]found to range from 0.21 to 15.41 Bq/kg. The highest activity concentration of [Formula: see text]Cs was observed in sample no. 26 in North of Qatar. The mean value was found to be around 2.15 ± 0.27 Bq/kg. These values lie within the expected range relative to the countries in the region. It is expected that this contamination is mainly due to the Chernobyl accident on 26 April 1986, but this conclusion cannot be confirmed because of the lack of data before this accident.

The determination of trace amounts of natural 133Xe in gas under high radon activity concentration levels

2013 ◽  
Vol 122 ◽  
pp. 9-15 ◽  
Author(s):  
Chongyang Zhou ◽  
Guoqing Zhou ◽  
Shujuan Feng ◽  
Yuren Jin ◽  
Xinhua Zhao ◽  
...  
Keyword(s):  
Activity Concentration ◽  
Radon Activity ◽  
Concentration Levels

Determination of Activity Concentration Levels of 238U, 232Th, and 40K in Drinking Water in a Gold Mine in Ghana

2010 ◽  
Vol 99 ◽  
pp. S149-S153
Author(s):  
A. R. Awudu ◽  
E. O. Darko ◽  
C. Schandorf ◽  
E. K. Hayford ◽  
M. K. Abekoe ◽  
...  
Keyword(s):  
Drinking Water ◽  
Activity Concentration ◽  
Gold Mine ◽  
Determination Of Activity ◽  
Concentration Levels

Features of phosphorus-calcium metabolism in children with neurogenic disorders of urination

2020 ◽  
Vol 24 (1) ◽  
pp. 45-50
Author(s):  
Yu. F. Lobanov ◽  
D. Y. Latyshev ◽  
Ya. F. Zverev ◽  
N. A. Tekuteva ◽  
N. M. Mikheeva
Keyword(s):  
Connective Tissue ◽  
Calcium Metabolism ◽  
Point System ◽  
Industry Standards ◽  
Muscular Dysfunction ◽  
Connective Tissue Dysplasia ◽  
Calcium And Phosphorus ◽  
Comparison Of The Results ◽  
Neurogenic Disorders

THE AIM: To study the characteristics of phosphorus-calcium metabolism in patients with neurogenic disorders of urination, taking into account the severity of the manifestations of connective tissue dysplasia. PATIENTS AND METHODS. The study included 90 children, including 60 children with neuro-muscular dysfunction of the bladder (NMDB) and 30 children with enuresis from the age of 5 to 15 years. The diagnosis was established based on a comprehensive examination and according to industry standards. Connective tissue dysplasia was diagnosed in children with the detection of 6 or more small external or visceral manifestations involving 3 or more organs from different systems. Assessment of the severity (severity) of connective tissue dysplasia was carried out according to the point system proposed by T.I. Kadurina et al. Each group was divided into subgroups depending on the severity of the manifestations of connective tissue dysplasia. The determination of the level of calcium and phosphorus in the blood and urine, as well as the calculation of the calcium-creatinine coefficient followed by a comparison of the results in these groups and subgroups. To assess the significance of differences, the Mann-Whitney test was calculated, p <0.05 was considered significant. RESULTS. he level of calcium and phosphorus in the urine was slightly higher in children with enuresis, especially in the morning portion of urine, where the concentration of calcium was 26% higher than in patients with NMDB. At the same time, the value of calcium /creatinine coefficient was significantly higher in the group of patients with enuresis and was 2 times higher than the normative indicators, which indicates the importance of hypercalciuria in the development of enuresis. СONCLUSION. According to the obtained data, the severity of calciuria, determined by the value of the calcium-creatinine coefficient, is significantly higher in patients with enuresis than with NMDB.

Laser optoacoustic detection of trace concentration levels of ethylene, vinylchloride, and styrene in the atmosphere

1989 ◽  
Vol 54 (10) ◽  
pp. 2667-2673 ◽  
Author(s):  
Vojtěch Steiner ◽  
Pavel Engst ◽  
Zdeněk Zelinger ◽  
Milan Horák
Keyword(s):  
Detection Limit ◽  
Emission Line ◽  
Laser Line ◽  
Laser Source ◽  
Trace Concentration ◽  
Selective Determination ◽  
Hygienic Standard ◽  
Trace Concentrations ◽  
Concentration Levels

The optoacoustic analyzer with a tunable CO2 laser source employed in the present work permits a selective determination of ethylene in trace concentrations higher than 5 ppb (=detection limit for the 10P(14) emission line of the CO2 laser, ν = 949.5 cm-1) and of vinylchloride higher than 42 ppb (= detection limit for the 10P(22) CO2 laser line, ν= 942.4 cm-1). this method covers for both compounds the concentration range corresponding to the hygienic standard. It can be also used for the determination of styrene vapour with concentrations higher than 1.5 ppm.

Spectrophotometric Determination of Raceophenidol in Feed at Very Low Levels

1968 ◽  
Vol 51 (4) ◽  
pp. 752-755
Author(s):  
Edward L Pratt ◽  
Morris E Auerbach
Keyword(s):  
Spectrophotometric Determination ◽  
Growth Promotion ◽  
Ultraviolet Spectrum ◽  
Average Value ◽  
Collaborative Studies ◽  
Low Levels ◽  
Concentration Levels

Abstract Raceophenidol in feed at concentration levels intended for growth promotion of poultry can be estimated by a curvature inversion measurement related to the ultraviolet spectrum of derived p-methylsulfonylbenzaldehyde. The drug can be accurately measured at the 0.0005% level. Collaborative studies on the method showed an average value of 94 ± 10% of claim. The method is recommended for adoption as official, first action.

scholarly journals New Kinetic Spectrophotometric Method for Determination of Folic Acid in Pharmaceutical Formulations

2015 ◽  
Vol 50 ◽  
pp. 169-178
Author(s):  
Mouhammed Khateeb ◽  
Basheer Elias ◽  
Fatema Al Rahal
Keyword(s):  
Folic Acid ◽  
Spectrophotometric Method ◽  
Pharmaceutical Formulations ◽  
Fixed Time ◽  
Rate Data ◽  
Sulfuric Acid Medium ◽  
Significant Difference ◽  
Kinetic Spectrophotometric ◽  
Comparison Of The Results

A simple and sensitive kinetic spectrophotometric method has been developed for the determination of folic acid (FA) in bulk and pharmaceutical Formulations. The method is based on the oxidation of FA by Fe (III) in sulfuric acid medium. Fe (III) subsequently reduces to Fe (II) which is coupled with potassium ferricyanide to form Prussian blue. The reaction is followed spectrophotometrically by measuring the increase in absorbance at λmax 725 nm. The rate data and fixed time methods were adopted for constructing the calibration curves. The linearity range was found to be 1–20 μg mL-1 for each method. The correlation coefficient was 0.9978 and 0.9993, and LOD was found to be 0.91 and 0.09 μg mL-1 for rate data and fixed time methods, respectively. The proposed method has been successfully applied to the determination of FA in formulations with no interference from the excipients. Statical comparison of the results shows that there is no significant difference between the proposed and pharmacopoeial methods

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