Nuclear Science and Technology, Vol. 4, No. 1 (2014), pp. 76-83
Some results of NAA collaborative study in white rice perfonned at Dalat Nuclear Research Institute
T.Q. Thien', C D . Vu, H.V. Doanh, N.T. Sy Dalat Nuclear Research Institute 01 Nguyen TuLuc St.. Dalat Lam Dong
*EmaiL [email protected] (Received 5 March 2014. accepted 14 March 2014)
Abstract: White rice is a main food for Asian people. In the framework of Forum for Nuclear Cooperation in Asia (FNCA), therefore, the eight Asian countries: China, Indonesia, Japan, Korea, Malaysia, the Philippines, Thailand and Vietnam selected whhe rice as a common target sample for a collaboration study since 2008. Accordingly, rice samples were purchased and prepared by following a protocol that had been proposed for this study. The groups of elements that were analyzed by using neutron activation analysis in the white rice samples were toxic elements and nutrient elements, including: Al, As, Br, Ca. CI, Co, Cr, Cs, Fe, K. Mg. Mn, Na, Rb and Zn. The analytical results were compared between the different countries and evaluated by using the Tolerable Intake Level of World Health Organization (WHO) and Recommended Dietary Allowance or Adequate Intake (AI) of the U.S. Institute of Medicine (lOM) guideline values. These tbta will be ver>' usehj] in the monitoring of the levels of food contamination and in the evaluation of the nutritional status for people living in Vietnam and other Asian countries.
Keywon]s: White rice, neutron activation analysis, FNCA,tolerable intake level, dietary reference intakes, adequate intake.
I. INTRODUCTION Utilization in the framework of the forum FNCA. Viemam has participated in the FNCA FNCA (Forum for Nuclear Cooperation ^ j ^ ^ ^ 200O
in Asia) was formally established in March
1999 at the 10* session of the Intemational ^ ^^ FN^A workshop held in Dalat, Conference on Nuclear Cooperation in Asia Vietnam, in 2008, the eight among twelve region ICNCA (Intemational Conference for "^^"^^^^ " ' " " ^ ^ ^ °f * ^ ^N^A which are Nuclear Cooperation in Asia) initiated and C^ina, hidonesia, Malaysia, Japan, Korea, the fiinded by the Japanese government. FNCA is Philippines, Thailand and Viemam. agreed to supposed to enhance mutual understanding, Participate in a collaborative study on the exchange ofinformation and experience to social ^^'y^is of food samples as a sub-project . , , • A - •!,„ „!, thematic m NAA. White rice has been selected and economic development in Asia through
,, , ^- . L I I- .- „^ as research subiects for this work because of its research, collaboration, technology applications "^ '^^^ J
initiatives for peaceful pmposes. Up to 2012, taponance as the basic staple food for people FNCA has 12 member countries, includmg: ^holives in Asia. Specifically, the major rice Australia, Bangladesh, Chma, Indonesia. Producmg countries in Asia are China. India, Malaysia, Japan. Kazakhstan, K o , ^ Mongolia, Indonesia, Malax sia, Bangladesh, Thailand, the Philippines. Thailand and Vietnam. Vietnam, etc. These countries accounts for over
80% of production and consumption of rice in NAA (Neutron Activation Analysis) is the world. This highlights the importance of the one of the projects under the ResearchReactor
TRAN QUANG THIEN et al.
n. EXPERIMENTS A. Sample collection and preparation information gained from the study because nee
is the staple food as well as providing a large portion ofthe calories in the Asian diet [1].
The objective of this study was to determine the inorganic elements in the white rice of Vietnam and compared it with seven Asian countries by NAA method, these resuUs are preliminary by the level of nutrients and toxic elements in rice for safety.
Table LThe information sampling of Vietnam's rice samples at Department of Agriculture and Rural Development Centre Tiengiang province
Eighteen samples were collected from the Department of Agriculture and Rural Development Centre Tiengiang province agricultural seed wherein rice is the most common type on the market which are presented in Table I.
No. Type
1 Ham Chau Rice 2
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
IR 50404 Rice Japan 504 Rice Jasmine 85 Rice
Jasmine Rice OM 4218 Rice OM 4900 Rice OM5451 Rice OM 5472 Rice OM 5976 Rice OM 6162 Rice OM 6377 Rice OM 6976 Rice Otim Rice
Seri Rice Tai Nguyen Rice Taiwan Fragrant Rice
Thom Lai Rice The collected rice samples were brought to the lab and washed with distilled water and then dried in a drying oven at a temperature of 60 ''C for 4 hours, then ground into fine particles using an agate mortar in order to prevent contamination. Rice samples were repeatedly ground until a particle size of 60 meshes. Finally, the samples were subdivided into subsamples weighing from 100-300 mg prior to analysis by INAA.[I]
B. Analysis
The rice samples were analyzed by INAA in Dalat Nuclear Research Institute. The analytical procedures are followed with ISO/IEC 17025 [2]. A concurrent analysis of reference standard samples for quality control was made for each batch of analysis. Analyses were made using a combination of both short and long irradiations. The HPGe detector with
77
SOME RESULTS OF NAA COLLABORATIVE STUDY IN WHITE RICE ...
multichannel analysis system was used to Tbe resuh of standard reference material measure the gamma rays from the sample after was shown in Table II and the result of fifteen elements concentrations in eighteen samples of white rice are in Table HI.
irradiation. The concentration of the elements was calculated using the relative method and/or k-zero method.
i n . RESULTS AND DISCUSSION A. Tbe content of elemente in vAute rice samples
Table II. Result of standard reference material IAEA-V-10
In Table II, The average result are caculated through 3 times analysis, it's not much different to the value of certificate. The Z-score of all elements is lower than 2, that mean this results are satisfactory.
No.
1 2 3 4 5 6 7 8 9 10 11 12 13
Ele.
Mg Ca CI Mn Na K Br Sc Cr Fe Co Zn Rb
Aver.
1579 20865 7360
46 507 20119
7.3 0.016
6.6 196 0.15 25.5 7.7
Sd.
121 2892 100
5 9 3530
0.5 0.002
0.5 21 0.03
2.2 0.5
Cert 1360 21600 47 500 21000
8 0.014
6.5 186 0.13 24 7.6
Z-score 1.81 -0.25
-
-0.20 0.78 -0.25 -1.40 1.00 0.20 0.48 0.67 0.68 0.20
Ana/Cot 1.161 0.966
-
0.979 1.014 0.958 0.913 1.143 1.015 1.054 I.I 54 1.063 1.013 A ver: A verage result:
Sd: Standart deviation Cert: Certificate
In Table m, the concentration of Mg element are not analyzed in all samples, elements concentration of Al, Ca and Fe are not obtamed and reported limit of detection, the result of other elements are included concentration and uncertainty. The highest concentration are K element the lowest come from Co and Cs. The other elements have no significant differences between all samples except Rb.
B. Comparing the elements concaitration in
^^lite rice of 8 countries
Results of fifteen elements: Al, As, Br,
Zn in rice samples determined by eight participating countries are summarized in Table 4. The results of quality control analysis for fifteen elements are summarized as a relative error (%) with absolute value and are shown in Fig. 1. The relative error of most of the elements evaluated in Fig. I were less than 15%, except for some few elements such as AI of Malaysia; Co of Vietnam; Mg of China, Korea and Vietnam, Mn and Na of Korea rice samples.
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SOME RESULTS OF NAA COLLABORATIVE STUDY IN WHITE RICE ..
Table IV. The analytical results of white rice (unit: mg/kg) [1]
Ele.
Al As Br Ca CI Co Cr Cs Fe K l l ^ Mn Na Rb Zn
"China
<4.46 0.55 0.35 N.A 264
<0.3 0.25
<0.D7 N.A 977 379 9.25 10.3
<3.35 15.3
Indonesia
<20.52 0.08 0.45
<4.53 210 0.77 0.38 0.09 4.65 739 131 9.95 7.7 7.64 24.2
"Japm
<1.66 0.1 0.5 49.5 239 N.A N.A N.A N.A 611 149 7.66 5.69 N.A 18.5
Korea
<l.38 0.13 0.19 53.9 193 0.005
<0.01 0.009 1.58 660 241 9.06 4.1 1.39 15.3
^Malaysia
<2 0.11 13.6
<10 225 0.026
<0.08 0.016
<5 573
<150 6.19 13.7 2.1 10.1
'Philippine
<2.82 0.07 5.35 39.1 236 N.A N.A N.A N.A 637 90 7.89 5.17 3.24 15.4
Thailand
<2.33 0.09 0.43
<15 239 0.022
<0.4 N.A
<16 620 59 9.23 4.58 1.34 21.4
"Vietnam (This work)
<5 0.12 0.33
<124 278 0.034
<0.5 0.045
<18 1077 N.A lO.l 17.4 6.8 22.5 N.A: not applicable; (a) Mean values are derived Svm four different samples; (b) Mean values &om a sample of known origin and two samples of unknown origin; (c) Mean values are derived £vm two different samples; (d) Mean values G-om four samples of unknown origin; (e) This work, average value of eighteen samples from known origins.
As can be seen from Table IV, the Al concentrations in rice saples from all participating countries were below the detection limit, hence only the limit of detection (LOD) were reported. Indonesia had an LOD value of 20.52 for Al, highest compared to other countries. Korea and Japan had the lowest LOD values in the eight countries. K concentration range is from 553 to
1077 mg/kg. K in Vietnam rice samples had the highest value which is 1077 mg/kg. CI and Mg have similarly eminent values. Seven elements of As, Br, CI, K, Mn, Na and Zn were determined by all participating countries, but LODs were not reported. As content of China had the highest value, 0.55 mg/kg and the other countries have equivalent levels of As, 0.1 mg/ks- Br concentrations of Malaysia
Indonesia and the Philippines were more than a dozen times higher than those of other countries. Five elements CI, K, Mn, Na and Zn did not differ significantly and the average content ofthe standard deviation were 236±27, 737±178, 8.67±1.32, 8.58±4.84 and 17.8±4.7 mg/kg respectively. Concentrations of Mg were reported by six countries excluding Malaysia and Vietnam. Thailand showed the lowest levels of Mg, 59 mg/kg, while the Mg content of China was the highest at 379 mg/kg.
Only three countries namely Japan, South Korea and the Philippines reported Ca data which were 49.5, 53.9 and 39.1 mg/kg respectively. In addition, the levels of Cr, Cs and Fe m Indonesian rice were higher compared to those of other countries.
T R A N Q U A N G THIEN et al.
C. Dietary intake level of the toxic elements and nutrition elements of 8 coimtries
To estimate the dietary intake level of inorganic constituents on consumption of white rice, it was necessary to conduct a survey of daily consumption of rice. For example, the amount of the average daily consumption of rice in Korea in 2000 was 256 grams, or in Vietnam in 2010 is 360 gram [3, 4] However,
rice consumption varies in different countries, and therefore a consensus value of 300 grams/day was set. to be able to compare the intake of As, CI. K, Mn. Na and Zn from rice consumption in all participating countries. This is to assess whether or not. the ingested levels ofthe elements can be considered as harmful or beneficial to human health. Data are shown in Table V.
Q China E3 Japan/Philippines
Al AS Br Ca CI Co Cr Cs Fe K Mg Mn Na Rb Zn Fig. 1. The absolute value ofthe relative error (%)Hthe value analysis to value certification/reference.
Table V. The RDA value of 6 elements each day through white rice, assuming consumption of 300 grams /day for adults[ 1 ]
Ele.
As (Hg) Cl(mg) K(mg) Mn (mg) Na (mg) Zn (mg)
China 165 79.2 293 2.78 3.09 4.59
Indonesia 24 63 222 2.99 2.31 7.26
Japan 30 71.7
183 2.30 1.71 5.55
Korea 39 57.9
198 2.72 1.23 4.59
pialaysia 33 67.5
172 1.86 4.11 3.03
Philippine 21 70.8
191 2.37 1.55 4.62
Thailand 27 71.7
186 2.77 1.37 6.42
Vietnam (This work)
36 83.4 323 3.03 522 6.75 The WHO has established a Tolerable
Intake Level for weekly consumption, which is 15 mg/kg of body weight for As [5]. Assuming a body weight of 70 kg of an adult, the Tolerable Intake Level for As daily consumption will be 150 microgram As. In addition, the Institute of Medicine (lOM) in the United States has established the value of the
Recommended Dietar> Allowance (RDA) or adequate intake (Ai) for the necessary elements [6. 7]. Zn has the highest RDA of 11 mg/day for men. Al highest values for CI. Mn defined by the lOM is 2 3 g/day for all adults, for Na and K. the highest Al values are respectively 1.5and4.7 2./dav.
SOME RESULTS OF NAA COLLABORATIVE STUDY IN WHITE RICE ., Calculations for the RDA or AI for the
elements As, CI, K, Mn, Na, Zn are shown in Figure 2.Tolerable hitake Level of As in China is higher than Tolerable Intake Level of WHO which was about 10%, for the other countries.
The level of Mn is almost equal to the value of the RDA of lOM. This shows just rice consumption of 300 g/day may provide sufficient Mn necessary for the human body.
The intake level for the remaining elements (CI, K, Na and Zn) were below the RDA or AI.
In the case of Zn, the range of daily consumption from 21.6% (Malaysia, Indonesia) to 51.9% (Indonesia) can only supply approximately 21.6% to 51.9% Zn necessary for the human body. Similarly, consumption of CI at 2.5% to 3.6%, K at 3.7%
to 6.2% and 0.3% Na were below the recommended values. These essential elements can be obtained anyway, from other foods such as meat, fish, vegetables, eggs, milk, etc. which are eaten together with the rice.
IV. CONCLUSIONS
A collaborative study on the determination of elemental abundance in rice using NAA was participated in by eight
countries namely China, Indonesia, Japan, Korea, Malaysia, the Philippines, Thailand and Vietnam. A total of fifteen elements in thirty five samples of white rice collected from eight countries were determined by INAA method.
Within the framework of project participants FNCA/NAA, NAA laboratory of Vietnam has collected and analyzed fifteen elements in eighteen samples of white rice types. Results of Vietnam's rice has been compared with the results of the seven countries participating members.
The analytical data were compared between the participatmg countries and assessed accordmg to the daily intake using the guideline values set by the WHO and lOM.
The results showed an elevated amount of As in Chinese rice which exceeded by approximately 10%, the RDA recommended by WHO. In addition the research gave an overview of the levels of nutritional elements Na, Mn, CI, K and Zn in rice consumed in the eight countries. Information on the intakes of Mn (of approximately 100%), Zn, Na, CI (21.6-51.9) % and K (lower than 10%) in comparison to the requirements of lOM was obtained from the study.
Fig. 2. Assess daily nutrient consumption (%) for the six elements through white rice.
TRAN QUANG THIEN et al.
In fiiture, FNCA will cany on to expand the scope of research in elemental abundance in food samples to strengthen the collaboration between Asian countries for the continued application of NAA in the assessment for contammation and mineral potentiality in the basic foodstuffs.
ACKNOWLEDGEMENTS We would like to thank the MEXT of Japan for support of this research.
REFERENCES
[I] J. H. Moon et. al, A NAA collaborative study in white rice performed in seven Asian countries, Joumal of Radio- analytical Chemistry, Volume 291, Issue 1, pp 217-221 (January 2012).
[2] Center for Analytical Techniques (CATech), Dalat Nuclear Research Instimte (NRI),
•TCCS-MSH from 01 to 03'', Dalat, (2011).
[3] Ministry of Agriculture and Forestry, Agricultural and forestry statistical yearbook 2003. Ministry of Agriculmre and Forestry, Seoul, (2003).
[4] National Instimte of Nutrition, A review ofthe nutrition situation in Vietnam 2009-2010, Medical Publishing House, Hanoi, (2011).
[5] Worid Health Organization, Evaluation of certain food additives and contaminants, (Thirty-thu-d report of the Joint FAO/WHO Expert Committee on Food Additives). WHO Technical Report Series, No. 776, (1989), [6] Institute of Medicine, Food and Nutrition
Board, Dietary reference intakes for vitamin A, vitamin K, arsenic, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, anrfzZnc, National Academy of Sciences, Washmgton DC, (2001).
[7] Institute of Medicine, Food and Nutrition Board, Dietary reference intakes for water, potassium, sodium, chloride and sulfate.
National Academy of Sciences, Washington DC, (2004).