- Email: [email protected]
Study of the effect of gamma-irradiation on the activation energy value from the thermoluminescence glow curve
Accepted Manuscript Title: Studying on effect of gamma-irradiation toward the activation energy value from the thermoluminescence glow curve Author: Nguyen Duy Sang PII: DOI: Reference:
S1658-3655(16)30085-1 http://dx.doi.org/doi:10.1016/j.jtusci.2016.10.006 JTUSCI 345
To appear in: Received date: Revised date: Accepted date:
30-5-2016 23-9-2016 7-10-2016
Please cite this article as: N.D. Sang, Studying on effect of gamma-irradiation toward the activation energy value from the thermoluminescence glow curve, Journal of Taibah University for Science (2016), http://dx.doi.org/10.1016/j.jtusci.2016.10.006 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Studying on effect of gamma-irradiation toward the activation energy value from the thermoluminescence
ip t
glow curve
cr
Nguyen Duy Sang1,2,*
College of Rural Development, Can Tho University, Can Tho 270000, Viet Nam
2
Faculty of Physics and Engineering Physics, University of Science, Ho Chi Minh
Abstract
[email protected]
M
*
an
700000, Viet Nam
us
1
d
The chilli powder samples were irradiated by 60Co gamma-source at the absorbed dose of
Ac ce pt e
2, 4, 6 and 8 kGy. This study calculates the activation energy value (E) from the thermoluminescence (TL) glow curves by the initial rise method (IR). For non-irradiated samples, the E value is 0.58 eV while the irradiated samples have higher value 0.84 eV. That allows us to distinguish between irradiated and non-irradiated chilli powder and be able to identify dose assessment of gamma irradiated samples.
Keywords
Thermoluminescence, activation energy, gamma-irradiation, chilli
1 Introduction Nowadays, there are over 55 countries in the world having accepted to use food, spices and fruits irradiated [1]. The food irradiation at a suitable dose helps prolong the lifespan 1
Page 1 of 12
of food, slow down sprouting of fruits, kill insects and parasites causing diseases, extend ripening time of fruits, avoid mold, and prevent rotting; therefore, these irradiated food and fruits can be used in longer period of time. However, overdose irradiated food makes reduce nutrient content and causing uncomfortable odor. Therefore, a reliable method to
ip t
check the authenticity of irradiated products is critically necessary. It is well-known that thermoluninescence (TL) materials usually exhibits a very complex
cr
TL glow curve structure with non-well peaks and as such, it cannot be analyzed by using the commonly accepted- physical models to explain the trap structure [2-4]. There are a
us
variety of methods used to explain TL process and evaluate the kinetic parameters from TL glow curves. These analysis methods include: glow curve deconvolution (GCD),
an
computerized glow curve deconvolution (CGCD), peak shape (PS), initial rise (IR), whole glow peak (WGP), isothermal decay (ID), three-points (TP) [2; 5-7] and etc. This paper reports on the estimation of the E values calculated from the TL glow curves of
M
polymineral phases isolated from the chilli powder samples in Vietnam by using the IR method in order to determine the activation energy (E) value for detecting irradiated food.
d
However, to distinguish irradiated and non-irradiated samples, the method of E
Ac ce pt e
estimation to detect irradiated food was used instead of basing on the TL glow ratios [8].
2 Experimental methods
The chilli powder was collected from the supermarket in Vietnam where the irradiation processing for food preservation has not yet implemented, and subdivided into nylon bags of sample which were about 20 g for each. Before irradiation and analysis, the samples were stored in the dark at room temperature. The TL analysis was also conducted on a non-irradiated sample to check the reliability of the method under investigation. The procedure recommended by the European Committee for Standardization [9] was followed to separate minerals from the chilli powder samples. The chilli powder samples as a whole, as well as minerals transferred on discs, were irradiated under electronic equilibrium conditions with a Cobalt-60 gamma-irradiator (Gamma chamber GC-5000, BRIT, India) at the Nuclear Research Institute (NRI), in Vietnam. The dose values were
2
Page 2 of 12
calculated to use irradiation time and the dose rate (3.6 kGy/h). An Rexon-reader machine UL-320 (equipped with PC and Windows applications software) was used to record and analyze the TL curves; the following instrumental setting were chosen: initial temperature: 70 °C, heating speed: 5 oC/s, final temperature: 100 oC to 250 oC. After
ip t
mineral isolation and after irradiation, specimens were stored at 50 oC overnight before TL measurements.
cr
Garlick and Gibson proposed a simple method to evaluate E in TL material that is an
initial rise method (IR) [10]. This method is based on the premise that occupancies of the
us
relevant states remain almost constant for the lowest temperature side of the TL peak and, consequently, this side of the peak will follow an exponential dependence regardless of
an
the kinetic order and the applicability of the quasi-equilibrium approximation where ITL ∝ exp(-E/kT). An Arrhenius plot (ln ITL vs 1/T) allows us to evaluate the E that can be obtained from the slope -E/k, regardless of any other kinetic parameters [8]. Fig. 1 shows
M
an example of an IR region of a glow peak. The low temperature peak tail in this region increase up to a critical temperature TC which is less than TM. The values of E from the
d
IR remain true for some critical values of temperature up to TC. TC should correspond to an intensity between 10 and 15% of IM [11]. The initial occupancies of traps and
Ac ce pt e
recombination centers are assumed to be constant only for a limited temperature range under TC.
3
Page 3 of 12
ip t cr us an M d
Ac ce pt e
Fig. 1. The initial rise (IR) region of a TL glow peak
3 Results and Discussion
The effect of the absorbed doses on the TL values in chilli powder obtained at different temperatures is presented in Fig. 2. It was seen that the TL value at each temperature increased together with increasing absorbed dose in the product. Maximum TL values for each dose were observed at 200 °C. As observed, the main differences between irradiated and non-irradiated samples are based on (i) the intensity and (ii) the shape of the glow emission [8]. The obtained ratio among the TL intensities of the samples allows us to discriminate irradiated from non-irradiated samples, even after longer periods of time (up to 1 month) and that is one order of magnitude less than the maximum recommended by the committee of experts from the FAO/WHO/IAEA [12] for conservation of herbs, spices or seasonings.
4
Page 4 of 12
ip t cr us an M d
Ac ce pt e
Fig. 2. Thermoluminescence intensities of irradiated chilli powder The E values obtained by the IR method for chilli powder are given in Table 1. The E values for different doses (0 and 8 kGy) at the same times of storage (360 h) is significantly different (Fig. 3). The IR method makes use of the existence, in the glowcurve, of a temperature range (Table 1) where, while the integral exponential factor remains practically unitary, the Boltzmann probability factor increases with T and therefore rules the curve shape [13]. The effect of the storage is appreciated in Fig. 4, where as expected, the intensity of the 8 kGy irradiated aliquots decreases with the elapsed time due to the fading effect that also contributes to modify the shape of the curve (Fig. 5). The 8 kGy TL curves stored for 360 h starts to grow at temperatures lower than 122 oC whereas the starting point of the glow emission from samples stored at 720 h raises at 128 oC. The E values for 8 kGy-irradiated samples stored from 360 h to 720 h where, as observed in Table 1, this kinetic parameter is gradually increasing with the
5
Page 5 of 12
passed time from 0.84 to 0.85 eV. For non-irradiated samples TL curves stored for 360 h and 720 h, the estimated E values showed Fig. 6. Therefore, we can consider that the estimation of the E values using the IR method could be used to determine the length of
Ac ce pt e
d
M
an
us
cr
ip t
time between irradiation processing and the TL analysis in Table 1 and Fig. 7.
Fig. 3. The E values for different doses (0 and 8 kGy) at the same times of storage
6
Page 6 of 12
ip t cr us an M d
Ac ce pt e
Fig. 4. The E values for different times of storage (360 and 720 h) at the same dose (8 kGy)
7
Page 7 of 12
ip t cr us an M d
Ac ce pt e
Fig. 5. TL emission from a 8 kGy gamma iradiated polymineral phases isolated from chilli powder after 360 and 720 h of storage
8
Page 8 of 12
ip t cr us an M d
Ac ce pt e
Fig. 6. The E values of non-irradiated samples for different times of storage (360 and 720 h)
9
Page 9 of 12
ip t cr us an M d
Ac ce pt e
Fig. 7. Arrhenius plot of the 0, 2, 4, 6 and 8 kGy gamma irradiated dust stored 360 h The calculation of the E using IR method can be considered as a reasonably good estimation, although they can vary according to the preheating temperature [8]. Compared to the detection of food irradiation based on the normal glow ratios in [9; 1415], the IR method is calculated to ensure fewer errors, correlation coefficient (r2) must be at least 0.999 to identify irradiated foods.
4 Conclusions
The E value of irradiated and non-irradiated samples is very different. (E value of nonirradiated sample 0.58 eV and gamma-irradiation never lower than 0.84 eV). With the gradual-increased dose of irradiation, the E value of the sample does not raise, but rather decline a small dose. Additionally, the sample spending the shorter time of storage has the smaller E value than the sample with the longer time of storage. The results showed 10
Page 10 of 12
that IR method can be used to determine for irradiation food. The determination is not based on food TL intensity which is based on E values. The samples do not need to reirradiation is still defined irradiation. Compared with other methods, the IR requires enough experimental data, but also for the positive results. Therefore, this method can be
ip t
applied in practice for determining the dose of the chilli powder in Vietnam. We can also
cr
study and application of IR method for agricultural products and other foodstuffs.
us
Acknowledgements
This research was supported by the Nuclear Research Institute (NRI) of Vietnam in 2015.
[3]
[4] [5]
[6]
[7]
[8]
M
d
[2]
J. z. Farkas, C. M. ´csi-Farkas (2011) History and future of food irradiation. Trends in Food Science & Technology 22(2-3):121-126 N. Kucuk, A. H. Gozel, M. Yuksel, T. Dogan, M. Topaksu (2015) Thermoluminescence kinetic parameters of different amount La-doped ZnB2O4. Appl Radiat Isot 104:186. doi:10.1016/j.apradiso.2015.07.007 M. Topaksu, A. N. Yazici (2007) The thermoluminescence properties of natural CaF2 after β-irradiation. Nucl Instrum Methods Phys Res B 264 (2):293-301. doi:10.1016/j.nimb.2007.09.018 A. N. Yazici, T. Mustafa (2003) The analysis of thermoluminescence glow peaks of unannealed synthetic quartz. J Phys D: Appl Phys 36 (6):620 M. Isik, T. Yildirim, N. M. Gasanly (2015) Determination of trapping parameters of thermoluminescent glow peaks of semiconducting Tl2Ga2S3Se crystals. J Physics Chem of Solids 82:56-59. doi:10.1016/j.jpcs.2015.03.007 M. H. A. Mhareb, S. Hashim, S. K. Ghoshal, Y. S. M. Alajerami, M. A. Saleh, S. A. B. Azizan, N. A. B. Razak, M. K. B. Abdul Karim (2015) Influences of dysprosium and phosphorous oxides co-doping on thermoluminescence features and kinetic parameters of lithium magnesium borate glass. J Radioanal Nucl Chem 305 (2):469. doi:10.1007/s10967-015-3984-x A. M. Sadek, H. M. Eissa, A. M. Basha, G. Kitis (2014) Resolving the limitation of the peak fitting and peak shape methods in the determination of the activation energy of thermoluminescence glow peaks. J Lumin 146:418. doi:10.1016/j.jlumin.2013.10.031 V. Correcher, J. Garcia-Guinea (2013) Potential use of the activation energy value calculated from the thermoluminescence glow curves to detect irradiated food. J Radioanal Nucl Chem 298 (2):821-825. doi:10.1007/s10967-013-2473-3
Ac ce pt e
[1]
an
References
11
Page 11 of 12
[13] [14]
M
an
[15]
ip t
[12]
cr
[10] [11]
EN_1788 (2001), Foodstuffs-Thermoluminescence detection of irradiated food from which silicate minerals can be isolated. Brussels: European Committee of Standardization G. F. J. Garlick, A. F. Gibson (1948). Proc Phys Soc 60:574-590 S. W. S. McKeever (1988), Thermoluminescence of solids, vol 3. Cambridge University Press, Cambridge WHO (1980) Wholesomeness of irradiated food, report of a joint FAO/lAEA (OIEA)/WHO (OMS) expert committee, technical report series 659. World Health Organization, WHO, Geneva V. Pagonis, G. Kitis, C. Furetta (2006), Numerical and Practical Exercises in Thermoluminescence. Springer, United States of America S. Elahi, I. Straub, K. Thurlow, P. Farnell, M. Walker (2008) Referee analysis of suspected irradiated food. Food Control 19 (3):269. doi:10.1016/j.foodcont.2007.04.003 B. Engin (2007) Thermoluminescence parameters and kinetics of irradiated inorganic dust collected from black peppers. Food Control 18 (3):243. doi:10.1016/j.foodcont.2005.10.002
us
[9]
List of Table
1 2 3 4 5 6 7 8 9 10
Ac ce pt e
d
Table 1 E values (in eV), range used for the IR analysis and the linear fitting parameters (where r2 is the regression coefficient of fitting) obtained from the TL glow emission of polymineral phase isolated from chilli powder in Vietnam at different doses and times of storage. 0 No E (eV) Dose/Storage Range ( C) r2 0 kGy/360 h 0 kGy/720 h 2 kGy/360 h 2 kGy/720 h 4 kGy/360 h 4 kGy/720 h 6 kGy/360 h 6 kGy/720 h 8 kGy/360 h 8 kGy/720 h
0.58 0.62 0.88 0.91 0.87 0.89 0.86 0.88 0.84 0.85
153-198 137-176 141-175 131-169 139-167 127-169 128-162 133-173 122-158 128-165
± 0.01 ± 0.03 ± 0.01 ± 0.02 ± 0.03 ± 0.04 ± 0.03 ± 0.02 ± 0.01 ± 0.02
0.9997 0.9996 0.9997 0.9996 0.9997 0.9996 0.9995 0.9995 0.9992 0.9996
12
Page 12 of 12
S1658-3655(16)30085-1 http://dx.doi.org/doi:10.1016/j.jtusci.2016.10.006 JTUSCI 345
To appear in: Received date: Revised date: Accepted date:
30-5-2016 23-9-2016 7-10-2016
Please cite this article as: N.D. Sang, Studying on effect of gamma-irradiation toward the activation energy value from the thermoluminescence glow curve, Journal of Taibah University for Science (2016), http://dx.doi.org/10.1016/j.jtusci.2016.10.006 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Studying on effect of gamma-irradiation toward the activation energy value from the thermoluminescence
ip t
glow curve
cr
Nguyen Duy Sang1,2,*
College of Rural Development, Can Tho University, Can Tho 270000, Viet Nam
2
Faculty of Physics and Engineering Physics, University of Science, Ho Chi Minh
Abstract
[email protected]
M
*
an
700000, Viet Nam
us
1
d
The chilli powder samples were irradiated by 60Co gamma-source at the absorbed dose of
Ac ce pt e
2, 4, 6 and 8 kGy. This study calculates the activation energy value (E) from the thermoluminescence (TL) glow curves by the initial rise method (IR). For non-irradiated samples, the E value is 0.58 eV while the irradiated samples have higher value 0.84 eV. That allows us to distinguish between irradiated and non-irradiated chilli powder and be able to identify dose assessment of gamma irradiated samples.
Keywords
Thermoluminescence, activation energy, gamma-irradiation, chilli
1 Introduction Nowadays, there are over 55 countries in the world having accepted to use food, spices and fruits irradiated [1]. The food irradiation at a suitable dose helps prolong the lifespan 1
Page 1 of 12
of food, slow down sprouting of fruits, kill insects and parasites causing diseases, extend ripening time of fruits, avoid mold, and prevent rotting; therefore, these irradiated food and fruits can be used in longer period of time. However, overdose irradiated food makes reduce nutrient content and causing uncomfortable odor. Therefore, a reliable method to
ip t
check the authenticity of irradiated products is critically necessary. It is well-known that thermoluninescence (TL) materials usually exhibits a very complex
cr
TL glow curve structure with non-well peaks and as such, it cannot be analyzed by using the commonly accepted- physical models to explain the trap structure [2-4]. There are a
us
variety of methods used to explain TL process and evaluate the kinetic parameters from TL glow curves. These analysis methods include: glow curve deconvolution (GCD),
an
computerized glow curve deconvolution (CGCD), peak shape (PS), initial rise (IR), whole glow peak (WGP), isothermal decay (ID), three-points (TP) [2; 5-7] and etc. This paper reports on the estimation of the E values calculated from the TL glow curves of
M
polymineral phases isolated from the chilli powder samples in Vietnam by using the IR method in order to determine the activation energy (E) value for detecting irradiated food.
d
However, to distinguish irradiated and non-irradiated samples, the method of E
Ac ce pt e
estimation to detect irradiated food was used instead of basing on the TL glow ratios [8].
2 Experimental methods
The chilli powder was collected from the supermarket in Vietnam where the irradiation processing for food preservation has not yet implemented, and subdivided into nylon bags of sample which were about 20 g for each. Before irradiation and analysis, the samples were stored in the dark at room temperature. The TL analysis was also conducted on a non-irradiated sample to check the reliability of the method under investigation. The procedure recommended by the European Committee for Standardization [9] was followed to separate minerals from the chilli powder samples. The chilli powder samples as a whole, as well as minerals transferred on discs, were irradiated under electronic equilibrium conditions with a Cobalt-60 gamma-irradiator (Gamma chamber GC-5000, BRIT, India) at the Nuclear Research Institute (NRI), in Vietnam. The dose values were
2
Page 2 of 12
calculated to use irradiation time and the dose rate (3.6 kGy/h). An Rexon-reader machine UL-320 (equipped with PC and Windows applications software) was used to record and analyze the TL curves; the following instrumental setting were chosen: initial temperature: 70 °C, heating speed: 5 oC/s, final temperature: 100 oC to 250 oC. After
ip t
mineral isolation and after irradiation, specimens were stored at 50 oC overnight before TL measurements.
cr
Garlick and Gibson proposed a simple method to evaluate E in TL material that is an
initial rise method (IR) [10]. This method is based on the premise that occupancies of the
us
relevant states remain almost constant for the lowest temperature side of the TL peak and, consequently, this side of the peak will follow an exponential dependence regardless of
an
the kinetic order and the applicability of the quasi-equilibrium approximation where ITL ∝ exp(-E/kT). An Arrhenius plot (ln ITL vs 1/T) allows us to evaluate the E that can be obtained from the slope -E/k, regardless of any other kinetic parameters [8]. Fig. 1 shows
M
an example of an IR region of a glow peak. The low temperature peak tail in this region increase up to a critical temperature TC which is less than TM. The values of E from the
d
IR remain true for some critical values of temperature up to TC. TC should correspond to an intensity between 10 and 15% of IM [11]. The initial occupancies of traps and
Ac ce pt e
recombination centers are assumed to be constant only for a limited temperature range under TC.
3
Page 3 of 12
ip t cr us an M d
Ac ce pt e
Fig. 1. The initial rise (IR) region of a TL glow peak
3 Results and Discussion
The effect of the absorbed doses on the TL values in chilli powder obtained at different temperatures is presented in Fig. 2. It was seen that the TL value at each temperature increased together with increasing absorbed dose in the product. Maximum TL values for each dose were observed at 200 °C. As observed, the main differences between irradiated and non-irradiated samples are based on (i) the intensity and (ii) the shape of the glow emission [8]. The obtained ratio among the TL intensities of the samples allows us to discriminate irradiated from non-irradiated samples, even after longer periods of time (up to 1 month) and that is one order of magnitude less than the maximum recommended by the committee of experts from the FAO/WHO/IAEA [12] for conservation of herbs, spices or seasonings.
4
Page 4 of 12
ip t cr us an M d
Ac ce pt e
Fig. 2. Thermoluminescence intensities of irradiated chilli powder The E values obtained by the IR method for chilli powder are given in Table 1. The E values for different doses (0 and 8 kGy) at the same times of storage (360 h) is significantly different (Fig. 3). The IR method makes use of the existence, in the glowcurve, of a temperature range (Table 1) where, while the integral exponential factor remains practically unitary, the Boltzmann probability factor increases with T and therefore rules the curve shape [13]. The effect of the storage is appreciated in Fig. 4, where as expected, the intensity of the 8 kGy irradiated aliquots decreases with the elapsed time due to the fading effect that also contributes to modify the shape of the curve (Fig. 5). The 8 kGy TL curves stored for 360 h starts to grow at temperatures lower than 122 oC whereas the starting point of the glow emission from samples stored at 720 h raises at 128 oC. The E values for 8 kGy-irradiated samples stored from 360 h to 720 h where, as observed in Table 1, this kinetic parameter is gradually increasing with the
5
Page 5 of 12
passed time from 0.84 to 0.85 eV. For non-irradiated samples TL curves stored for 360 h and 720 h, the estimated E values showed Fig. 6. Therefore, we can consider that the estimation of the E values using the IR method could be used to determine the length of
Ac ce pt e
d
M
an
us
cr
ip t
time between irradiation processing and the TL analysis in Table 1 and Fig. 7.
Fig. 3. The E values for different doses (0 and 8 kGy) at the same times of storage
6
Page 6 of 12
ip t cr us an M d
Ac ce pt e
Fig. 4. The E values for different times of storage (360 and 720 h) at the same dose (8 kGy)
7
Page 7 of 12
ip t cr us an M d
Ac ce pt e
Fig. 5. TL emission from a 8 kGy gamma iradiated polymineral phases isolated from chilli powder after 360 and 720 h of storage
8
Page 8 of 12
ip t cr us an M d
Ac ce pt e
Fig. 6. The E values of non-irradiated samples for different times of storage (360 and 720 h)
9
Page 9 of 12
ip t cr us an M d
Ac ce pt e
Fig. 7. Arrhenius plot of the 0, 2, 4, 6 and 8 kGy gamma irradiated dust stored 360 h The calculation of the E using IR method can be considered as a reasonably good estimation, although they can vary according to the preheating temperature [8]. Compared to the detection of food irradiation based on the normal glow ratios in [9; 1415], the IR method is calculated to ensure fewer errors, correlation coefficient (r2) must be at least 0.999 to identify irradiated foods.
4 Conclusions
The E value of irradiated and non-irradiated samples is very different. (E value of nonirradiated sample 0.58 eV and gamma-irradiation never lower than 0.84 eV). With the gradual-increased dose of irradiation, the E value of the sample does not raise, but rather decline a small dose. Additionally, the sample spending the shorter time of storage has the smaller E value than the sample with the longer time of storage. The results showed 10
Page 10 of 12
that IR method can be used to determine for irradiation food. The determination is not based on food TL intensity which is based on E values. The samples do not need to reirradiation is still defined irradiation. Compared with other methods, the IR requires enough experimental data, but also for the positive results. Therefore, this method can be
ip t
applied in practice for determining the dose of the chilli powder in Vietnam. We can also
cr
study and application of IR method for agricultural products and other foodstuffs.
us
Acknowledgements
This research was supported by the Nuclear Research Institute (NRI) of Vietnam in 2015.
[3]
[4] [5]
[6]
[7]
[8]
M
d
[2]
J. z. Farkas, C. M. ´csi-Farkas (2011) History and future of food irradiation. Trends in Food Science & Technology 22(2-3):121-126 N. Kucuk, A. H. Gozel, M. Yuksel, T. Dogan, M. Topaksu (2015) Thermoluminescence kinetic parameters of different amount La-doped ZnB2O4. Appl Radiat Isot 104:186. doi:10.1016/j.apradiso.2015.07.007 M. Topaksu, A. N. Yazici (2007) The thermoluminescence properties of natural CaF2 after β-irradiation. Nucl Instrum Methods Phys Res B 264 (2):293-301. doi:10.1016/j.nimb.2007.09.018 A. N. Yazici, T. Mustafa (2003) The analysis of thermoluminescence glow peaks of unannealed synthetic quartz. J Phys D: Appl Phys 36 (6):620 M. Isik, T. Yildirim, N. M. Gasanly (2015) Determination of trapping parameters of thermoluminescent glow peaks of semiconducting Tl2Ga2S3Se crystals. J Physics Chem of Solids 82:56-59. doi:10.1016/j.jpcs.2015.03.007 M. H. A. Mhareb, S. Hashim, S. K. Ghoshal, Y. S. M. Alajerami, M. A. Saleh, S. A. B. Azizan, N. A. B. Razak, M. K. B. Abdul Karim (2015) Influences of dysprosium and phosphorous oxides co-doping on thermoluminescence features and kinetic parameters of lithium magnesium borate glass. J Radioanal Nucl Chem 305 (2):469. doi:10.1007/s10967-015-3984-x A. M. Sadek, H. M. Eissa, A. M. Basha, G. Kitis (2014) Resolving the limitation of the peak fitting and peak shape methods in the determination of the activation energy of thermoluminescence glow peaks. J Lumin 146:418. doi:10.1016/j.jlumin.2013.10.031 V. Correcher, J. Garcia-Guinea (2013) Potential use of the activation energy value calculated from the thermoluminescence glow curves to detect irradiated food. J Radioanal Nucl Chem 298 (2):821-825. doi:10.1007/s10967-013-2473-3
Ac ce pt e
[1]
an
References
11
Page 11 of 12
[13] [14]
M
an
[15]
ip t
[12]
cr
[10] [11]
EN_1788 (2001), Foodstuffs-Thermoluminescence detection of irradiated food from which silicate minerals can be isolated. Brussels: European Committee of Standardization G. F. J. Garlick, A. F. Gibson (1948). Proc Phys Soc 60:574-590 S. W. S. McKeever (1988), Thermoluminescence of solids, vol 3. Cambridge University Press, Cambridge WHO (1980) Wholesomeness of irradiated food, report of a joint FAO/lAEA (OIEA)/WHO (OMS) expert committee, technical report series 659. World Health Organization, WHO, Geneva V. Pagonis, G. Kitis, C. Furetta (2006), Numerical and Practical Exercises in Thermoluminescence. Springer, United States of America S. Elahi, I. Straub, K. Thurlow, P. Farnell, M. Walker (2008) Referee analysis of suspected irradiated food. Food Control 19 (3):269. doi:10.1016/j.foodcont.2007.04.003 B. Engin (2007) Thermoluminescence parameters and kinetics of irradiated inorganic dust collected from black peppers. Food Control 18 (3):243. doi:10.1016/j.foodcont.2005.10.002
us
[9]
List of Table
1 2 3 4 5 6 7 8 9 10
Ac ce pt e
d
Table 1 E values (in eV), range used for the IR analysis and the linear fitting parameters (where r2 is the regression coefficient of fitting) obtained from the TL glow emission of polymineral phase isolated from chilli powder in Vietnam at different doses and times of storage. 0 No E (eV) Dose/Storage Range ( C) r2 0 kGy/360 h 0 kGy/720 h 2 kGy/360 h 2 kGy/720 h 4 kGy/360 h 4 kGy/720 h 6 kGy/360 h 6 kGy/720 h 8 kGy/360 h 8 kGy/720 h
0.58 0.62 0.88 0.91 0.87 0.89 0.86 0.88 0.84 0.85
153-198 137-176 141-175 131-169 139-167 127-169 128-162 133-173 122-158 128-165
± 0.01 ± 0.03 ± 0.01 ± 0.02 ± 0.03 ± 0.04 ± 0.03 ± 0.02 ± 0.01 ± 0.02
0.9997 0.9996 0.9997 0.9996 0.9997 0.9996 0.9995 0.9995 0.9992 0.9996
12
Page 12 of 12