Journal of Nuclear and Radiochemical Sciences, Vol. 1, No. 1, pp. 19−22, 2000

19

Modern Nuclear Analytical Techniques and Their Applications in China
Chai Zhifang*Institute of High Energy Physics and Laboratory of Nuclear Analytical Techniques, Chinese Academy of Sciences,
P.O.Box 2732, Beijing 100080, China
Received: October 13, 1999
The earliest activities of nuclear analytical techniques (NATs) in China were much later than those in the developed countries, but since the late fifties a vast progress in the development of NATs has been made. This paper
will describe some latest achievements in the field of modern nuclear analytical techniques, including molecular
activation analysis, scanning proton microscope, accelerator mass spectrometry, synchrotron radiation-based Xray analytical techniques, and position sensitive spectrometry, etc. and their applications in environmental, biological, geological, and material science. The analytical quality assurance and related topics, like new type referencematerials for microbeam analysis, biological and environmental specimen banking, and biological monitor forenvironmental quality survey, will be outlined as well.

The earliest activities of nuclear analytical techniques (NATs)
in China can be traced back to the early fifties, much later thanin the developed countries. However, since the first nuclear
research reactor and low energy accelerator was put into operation in 1958, the NATs in China experienced a rapid growthstage, which was characterized by establishment of various
NAT methods and their extensive applications in interdisciplinary fields. Recently, the Chinese government has defined six
national goals, i.e., agriculture, environment, human health,energy and resources, materials, and information, as a guideline of major research direction, which are becoming strong
impetus to the development of NATs, because NATs can playa significant role in the above 6 aspects. In this paper, the latest achievements of NATs and their applications in China will
be described.
1. Hardware
Nowadays there are 10 research reactors available in themainland China (one high flux reactor with neutron flux of
1×1014 n/cm2/s, one heavy water reactor with 8×1013 n/cm2/s, 4
swimming-pool type reactors with 2×1013 n/cm2/s and 4 miniature neutron source reactors (MNSR) with 1×1012 n/cm2/s. It
should be mentioned that five MNSRs have been exported toforeign countries. Hou et al.1,2 discussed the application of the
MNSR in neutron activation analysis (NAA), especially inepithermal NAA. The project to establish a new high flux
reactor with 5×1014 n/cm2/s has been approved, which, hopefully, will be completed until 2003. In addition, 2 synchrotron
radiation machines, 3 accelerator mass spectrometers (AMS), 3
scanning proton microprobes (SPM) and 2 intensive beam currency and low energy positron spectrometers are available.
Also, over 100 low energy accelerators have been providing
the routine service for PIXE and other nuclear analytical tasks.
2. Molecular Activation Analysis (MAA) 3,4
The MAA is a variety of activation analysis methods that isable to provide the information on chemical species of elements of interest in a studied specimen, although its exact definition remains to be assigned.3,4 The so-called MAA is, in fact,
a combination of conventional NAA with physical, chemical
or biological separation procedures in order to meet the ever*Corresponding author. E-mail: chaizf@lnat.ihepa.ac.cn. FAX:
+86-10-62573660.

increasing need for chemical species study. Recently, study ofthe chemical species of a number of trace elements in biological, environmental and geological samples have been extensively performed by MAA at Institute of High Energy Physics(IHEP). The typical examples in this aspect are as follows:a) Platinum Group Elements. 5−12 The chemical species ofanomalous iridium at the geological boundary sediments,
mainly at the Cretaceous-Tertiary, were analyzed by MAA
based on a step by step dissolution procedure and phase isolation technique combined with radiochemical NAA. 5 − 7Interestingly, almost 50 % of iridium at the K-T boundary
clays exist in an acid-insoluble phase regardless to their continental or marine sedimentation origin, which imply that thispart of Ir was likely originated from the extraterrestrial matters.
The related work can refer to References 8−12. Recently, Daiet al.13 studied the chemical species of Ir and their influence on
the absorption and desorption of Ir in marine system.
b) Rare Earth Elements (REEs).14−17 REEs have been widely
applied as fertilizer and feed in China to enhance the output ofagricultural products, like rice, wheat, corn, sugarcane, tea andtobacco, etc. and animal husbandry, e.g., pig, chicken, fish andshrimp, etc. However, the knowledge about the real mechanism of biological effect of REEs is scarce, although a lot of invitro simulation experiments were done. The critical point liesin whether REEs can be combined with biological macromolecules, e.g., proteins, polysaccharides and DNA, in natural samples. Wang et al.15,16 have successfully identified two new
REEs-bound proteins mainly containing two subunits withmolecular weight of 14000 and 38700 and 5 new REEs-boundpolysaccharides with small molecular weights (10000 to
20000) in a natural plant, a species of fern (Dicranopteris
Dichotoma). The latest finding in this aspect is that an experimental evidence about the existence of DNA-binding REE
compound has been obtained.17 The molecular weight of the
REE-DNA band was about 22 kb in agarose gel electrophoresis and the REE contents of the REE-DNA compounds accountfor 0.087 % of the total REEs in the fern leaves.
c) Chromium.18−21 Chromium is an element which is considered to be related to the glucose and ester metabolism. Ding etal.18 applied the MAA to study the chemical species of chromium in a Cr-rich yeast that is used as a supplement for diabetes.
The experimental results indicated that Cr can enter the yeast
cell through the cell wall during the culture process and about
80 % Cr in the yeast cell exist in the protoplast fraction, whichhave been converted to the organic chromium. Feng et al.19,20
studied the metabolism of physiological amount of Cr (III)© 2000 The Japan Society of Nuclear and Radiochemical Sciences

Chai

20 J. Nucl. Radiochem. Sci., Vol. 1, No. 1, 2000
intragastrial administration in normal rats by using activablestable isotope 50Cr compound as a tracer.
d) Selenium.22−24 Selenium is one of the essential trace elements to human being. However, up to now almost all
research about the biological functions and chemical species of
Se was limited to animal test. Chen et al.22 studied the subcellular distribution of selenium and Se-containing proteins in the
nuclei, mitochondria, lysosome, microsome and cytoplasm
fractions of human liver samples by MAA. They found 8
kinds of Se-containing proteins with molecular weight of 335,
249, 106, 84.6, 70.5, 45.6, 14.8 and 8.5 kDa, respectively.
Among them the 335, 84.6 and 8.5 kDa proteins were individually present in one subcellular fraction, whereas the others
coexisted in two, three or four subcellular fractions. The mostabundant Se-containing proteins, 70.5 and 14.8 kDa, accounted
for 33.6% and 48.5% of the whole-liver soluble Se-containing
protein, respectively. The former was enriched in cytosol andthe latter in nuclei and mitochondria. Other related researches
in the chemical species of Se in environmental and biologicalsamples were also reported.23,24
Besides, iodine in marine algae and human liver,25−28 mercury in human scalp hair of pregnant women and their new
babies, urine and blood, 29−32 platinum in serum protein ofmice ,33 and others34−36 were studied.
3. Scanning Proton Microscope (SPM) 37−40
Three SPM facilities are located at Shanghai Institute for
Nuclear Research (SINR), Fudan University and Institute ofPhysics. Their proton energies range from 2 to 4 MeV andspace resolutions are about 1 to 2 µm. The SPM has been
employed to localize the distribution of elements of interest in
various matrices. A typical example is to identify an unknown
Pt-bearing mineral isolated from ultramafic-mafic rocks at
Xinji, Sichuan Province, Southwest China.40 The experimental
results show no any correlation between platinum and nickel orcopper, both of which are the main compositions in this mineral. Interestingly, a positive correlation is evident between platinum and arsenic. The correlation coefficient is about 0.80.
Further, based on the quantitative calculation, the chemical
formula of the unknown mineral can be derived as Pt1.379 As2.
Another latest work is to identify the source of single atmospheric particle by SPM. The workers at SINR found that the
distribution of lead is inhomogeneous in atmospheric particle.
In addition, the single particles from different sources, e.g.,soil, cement, vehicle exhaust, petroleum, ferrous smelter andcoal combustion, etc. possess different fingerprint spectra ofchemical element compositions. Based on the artificial nerve
network (ANN) method, the contribution rates of various
atmospheric pollution sources at winter season in the Shanghai
urban region have been estimated.
4. Accelerator Mass Spectrometry (AMS) 41−45
There are 3 sets of accelerator mass spectrometers, of which
two are in Beijing and one in Shanghai. A large number oflong-term radioactive nuclides, e.g., 14C, 10Be, 36Cl and 129I, etc.
in various environmental, geological and biological samples
have been determined. Liu’s group at Peking University studied
DNA adduction with 14C labeled nicotine and nicotine-derived
nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone(NNK), by AMS in mouse liver at doses equivalent to lowlevel exposure of humans. 44 A linearly positive correlation
between the number of DNA adducts and dose has been
observed, which implies that the nicotine is a potential carcinogen. The detection limit of this AMS measurement for DNA
adduct was as sensitive as 1 adduct per 1011 nucleotide molecules, which was 10−104 better than that of other conventional

techniques used for quantitative analysis of DNA adducts.
Recently, they used AMS to measure the adduction of micelung DNA with nicotine and to study the genotoxicity of an
insecticide pirimicarb, 2-dimethylamino-5, 6-dimethyl-pyrimidin(-4-)yl-dimethylcarbamate in mice liver in low dose level.
Another typical example of application of the AMS is to
study the paleoclimate in China according to radiocarbon dating of a loess profile located at Weinan, Shaanxi Province,
northwest China, and of a stalagmite of 1.2 m long taken from
Panglongdong Cave at Guilin, Guangxi Autonomous Region.42
The analytical results indicated that the climate during the
Holocene in China was generally warm and damp, but afterwards it experienced a short cold period during 10000−11000 a
B.P. A latest major project is to dating the archeological relics
for the Xia, Shang and Zhou Dynasties chronology.
5. Synchrotron Radiation-based Analytical Techniques46−50
In the mainland China there are two synchrotron radiation
facilities located at Beijing and Hefei, respectively. A new socalled third generation SR facility will be established in
Shanghai. Taking the SR at Institute of High Energy Physics
as an example, versatile nuclear analytical techniques havebeen or are being implemented, mainly SR-XRF (X-ray fluorescence), SR-XD (X-ray diffraction), SR-SAS (small angular
scattering), EXAFS (Extended X-ray absorption fine structure)and XANES (X-ray absorption near edge spectroscopy), etc.
The SR provides a strong beam intensity of X-ray with microanalysis characteristics to enable the enhancement of analyticalsensitivity and the decrease of sampling amount. Feng et al.30
studied the change of mercury content in pregnant women’s
scalp hair during their pregnancy by SRXRF and found thatthe mercury content in their hair samples decreases in the periodof pregnancy. Further, on the basis of analysis of hair mercury
contents in their new-born babies, an interesting transformation phenomenon of mercury from mother to infant was
revealed. Other related work includes the observation of concentration variation of some essential trace elements in serum
protein of mice with and without the cis-platin therapy by thetechnique of SRXRF.33 Liu et al.46 studied the multi-elemental
position distribution in some biological tissues by micro-beam
SRXRF technique. Shao et al.47 applied the SRXRF microprobe
to observe the change of some elements in human gastric cancer tissue.
EXAFS is a powerful tool to study the structure of compounds.49,50 Wang et al. 50 used it to study the local atomic
structures of liquid GaSb and InSb.
6. Position Sensitive Spectroscopy (PSS) 51,52
In order to enhance the energy resolution of conventional Xray detection, e.g., Si (Li) detector, and to enable the chemical
species study of some important elements in systems of interest, a position sensitive spectroscopy has been established withthe energy resolution of eV order of magnitude, e.g., 25, 15
and 7 eV for 55Fe, Ti and Si, respectively.51 It is based on thedispersive function of flat crystal, which diffracts the X-rays
with different energies along a certain space direction. Then, aposition sensitive detector with high ability of space resolution
is used to record the X-rays at different space positions, whichenables the detection of X-ray with high ability of energy resolution. The results of Hu, et al.,51 clearly show the satellite
spectrum of Si Kα. Liu et al.52 also observed most of the main
characteristic X-rays of rare earth elements, which were wellseparated for just one time of detection by PSS. The problem
of serious overlapping and interference of adjacent line peaksof REEs in the conventional PIXE can be solved.

Modern Nuclear Analytical Techniques
7. Analytical Quality Assurance of NATs and Related
Work 53−60
The quality assurance is a critical factor for all analyticaltechniques. In a certain sense, the NATs are advantage overthe non-nuclear techniques, because their error sources aretraceable. Chai53 summarized the Chinese reference materials
for environmental and biological researches. Mao and Chai54
examined the change of the distribution homogeneity of elements with different chemical behaviors in a range of sampling
amount from milligram to microgram. Other certification
work of reference materials by NTAs and related techniques
can refer to References 55-57.
Recently, Shao et al.58,59 successfully prepared some standard reference materials for microbeam analysis. Metal, alloy
and compound films were prepared by vacuum evaporation.
Homogeneity of the films was examined by SRXRF and scanning electron microscope, which is comparable with that ofsimilar reference materials prepared in USA. The certified elements include As, Br, Ca, Co, Cr, Cu, F, Fe, Ga, K, Mn, Se
and Zn, which can basically meet the requirement for practicalsample analysis by microbeam techniques, e.g., SPM or
SRXRF.
The biological and environmental specimen banking(BESB) and biological monitoring for environmental pollution
are the other two related research topics. Zhang et al.60 reported a pilot BESB established at IHEP, where 62 normal humanliver samples and other biological and environmental samples
have been stored at –80oC. It is useful for environmental monitoring, retrospective analysis and analytical quality survey.
Another one is to collect various species of lichen and mossfrom different regions in China, which are analyzed by NATs
and other techniques. The emphasis is given to monitor theatmospheric pollution of the Beijing city.
8. Perspectives
It is foreseeable that the nuclear analytical techniques withthe following advanced characteristics in sensitivity, precision,
reliability, accuracy, space resolution, speed, cost, chemical
species, dynamics and in situ analysis, are desirable with thetremendous development of science and technology in the next
century.
Acknowledgement. This work is financially supported by
National Natural Science of Foundation of China (NSFC) andChinese Academy of Sciences (CAS).
References(1) X. L. Hou, K. Wang, and Z. F. Chai, J. Radioanal. Nucl.
Chem. Articles 210, 137 (1996).
(2) X. L. Hou, Z. F. Chai, Q. F. Qian, C. S. Li, and K. Wang,
Fresenius J. Anal. Chem. 357, 1106 (1997).
(3) Z. F. Chai, X. Y. Mao, and Y. Q. Wang, ibid. 363, 477(1999).
(4) Z. F. Chai, Radioanalysis (in Japanese) 5, 1-4 (1997).
(5) Z. F. Chai, P. Kong, X. Y. Mao, and S. L. Ma, Science in
China, B 34, 1492 (1991).
(6) P. Kong, Z. F. Chai, X. Y. Mao, and S. L. Ma, J.
Radioanal. Nucl. Chem., Articles 151, 201 (1991).
(7) Z. F. Chai, P. Kong, X. Y. Mao, and S. L. Ma, J.
Radioanal. Nucl. Chem., Articles 192, 101 (1995).
(8) P. X. Ma, X. Y. Mao, Q. L. Hou, Z. F. Chai, Z. Y.
Ouyang, and H. L. Xu, Science in China, D 26, 74 (1996).
(9) C. S. Li, Z. F. Chai, X. F. Yang, X. L. Hou, and X. Y.
Mao, Talanta 44, 1313 (1997).
(10) N. J. Evans, Z. F. Chai, Paleo-Geogr. Climat. Ecol. 132,
373 (1997).

J. Nucl. Radiochem. Sci., Vol. 1, No. 1, 2000 21(11) C. S. Li, Z. F. Chai, X. Y. Mao, and H. Ouyang, Anal.
Chim. Acta 374, 93 (1998).
(12) C. S. Li, Z. F. Chai, X. Y. Mao, and H. Ouyang, Fresenius
J. Anal. Chem. 363, 602 (1999).
(13) X. X. Dai, Z. F. Chai, and X. Y. Mao, Chem. Geol. (inpress).
(14) F. Q. Guo, Y. Q. Wang, J. X. Sun, and H. M. Chen, J.
Radioanal. Nucl. Chem., Articles 363, 602 (1996).
(15) Y. Q. Wang, J. X. Sun, H. M. Chen, and F. Q. Guo, ibid.
Letters, 209, 91 (1997).
(16) Y. Q. Wang, L. Xu, J. X. Sun, F. Q. Guo, H. M. Chen, and
G. Y. Chao, Science in China, B 41, 266 (1998).
(17) Y. Q. Wang, P. Jiang, F. Q. Guo, Z. Y. Zhang, J. X. Sun,
L. Xu, and G. Y. Cao, Science in China, B 42, 357 (1999).
(18) W. J. Ding, Q. F. Qian, X. L. Hou, Z. F. Chai, W. Y.
Feng, and C. Y. Chen, Acta Nutrimenta Sinica 21, 95(1999) (in Chinese).
(19) W. Y. Feng, W. J. Ding, Q. F. Qian, and Z. F. Chai, Nucl.
Tech. 21, 731 (1998) (in Chinese).
(20) W. Y. Feng, W. J. Ding, Q. F. Qian, and Z.F. Chai, J.
Radioanal. Nucl. Chem. 237, 15 (1998).
(21) W. J. Ding, Z. F. Chai, W. Y. Feng, and Q. F. Qian, Biol.
Tra. Elem. Res. 63, 231 (1998).
(22) C. Y. Chen, P. Q. Zhang, X. L. Hou, and Z. F. Chai,
Biochim. Biophys. Acta 1427, 205 (1999).
(23) Z. F. Chai, J. B. Tian, and Q. F. Qian, Biol. Tra. Elem.
Res. 43-45, 177 (1994).
(24) J. B. Tian, Q. F. Qian, Z. F. Chai, K. Wang, and T. Qu, J.
Radioanal. Nucl. Chem., Articles 151, 287 (1991).
(25) X. L. Hou, Z. F. Chai, Q. F. Qian, N. Q. Liu, P. Q. Zhang,and K. Wang, Sci. Tot. Environ. 193, 161 (1997).
(26) X. L. Hou, Z. F. Chai, Q. F. Qian, X. J. Yan, and X. Fan,
ibid. 204, 215 (1997).
(27) X. L. Hou, Z. F. Chai, Q. F. Qian, C. S. Li, and C. Y.
Chen, Biol. Tra. Elem. Res. 56, 225 (1997).
(28) X. L. Hou, W. Y. Feng, Q. F. Qian, and Z. F. Chai,
Analyst 123, 2209 (1998).
(29) Z. F. Chai, W. Y. Feng, and Q. F. Qian, Biol. Tra. Elem.
Res. 43-45, 423 (1994).
(30) W. Y. Feng, Z. F. Chai, Q. F. Qian, and P. Q. Zhang, J.
Radioanal. Nucl. Chem., Articles 195, 67 (1995).
(31) W. Y. Feng, Z. F. Chai, and Q. F. Qian, ibid., Letters, 212,
61 (1996).
(32) Z. F. Chai, W. Y. Feng, and Q. F. Qian, Biol. Tra. Elem.
Res. 63, 95 (1998).
(33) N. Q. Liu, P. S. Liu, K. J. Wang, D. F. Chen, J. Y. Zhao,
and Q. Xu, Biol. Tra. Elem. Res. 71 (1999) (in press).
(34) Q. F. Qian, W. Y. Feng, C. Y. Chen, P. Q. Zhang, and Z.
F. Chai, J. Radioanal. Nucl. Chem., Letters, 212, 51(1996).
(35) Z. F. Chai, X. Y. Mao, F. G. Liu, and H. B. Fu, ibid.,
Articles 205, 295 (1996).
(36) C. Y. Chen, P. Q. Zhang, X. L. Lu, X. L. Hou, and Z. F.
Chai, Fresenius J. Anal. Chem. 363, 512 (1998).
(37) J. Q. Zhu, Y. M. Wang, and G. J. Legge, F. Nucl. Instr.
and Meth. B 77, 478 (1993).
(38) J. Q. Zhu, R. R. Lu, A. Q. Le, Y. M. Gu, C. Y. Yang, andY. M. Wang, ibid. 77, 422 (1993).
(39) S. L. Feng, M. Zhong, M. Q. Reng, N. Q. Liu, Y. Wang, J.
Q. Zhu, A. Q. Le, and R. R. Lu, ibid. 77, 375 (1993).
(40) X. L. Li, J. Q. Zhu, Y. M. Gu, X. K. Wu, and C. H. Tong,
Nucl. Sci. Tech. 6, 221 (1995) (in Chinese).
(41) C. E. Chen, Z. Y. Guo, S. Q. Yan, R. X. Li, M. Xiao, K.
Li, K. X. Liu, H. T. Liu, and R. J. Zhang, Nucl. Instr. andMeth. B 79, 624 (1993).
(42) Z. Y. Guo, K. X. Liu, K. Li, J. J. Wang, B. Li, X. Y. Lu,
C. E. Chen, T. M. Chen, S. X. Yuan, and S. J. Gao,
Radiocarbon 37, 705 (1995).
(43) Y. F. Liu, Z. Y. Guo, X. Q. Liu, T. Qu, and J. L. Xie, Pure

22 J. Nucl. Radiochem. Sci., Vol. 1, No. 1, 2000
Appl. Chem. 66, 305 (1994).
(44) X. S. Li, H. F. Wang, X. Y. Wang, Y. F. Liu, K. Li, Z. Y.
Guo, K. X. Liu, X. Y. Lu, and J. J. Wang, Radiocarbon
38, 347 (1996).
(45) J. Y. Shi, H. F. Wang, X. H. Wu, X. S. Li, Y. F. Liu, K.
Li, X. Y. Lu, J. J. Wang, and K. X. Liu, Chin. Sci.
Bulletin 42, 1675 (1997) (in Chinese).
(46) N. Q. Liu, H. R. Shao, D. X. Ma, Y. Deng, P. Liu, Z. G.
Ren, and S. J. Zhou, Nucl. Instr. and Meth. B 109, 368(1996).
(47) H. R. Shao, Q. Xu, R. Hong, Y. R. Wu, and Z. Y. Chao,
Intern. J. PIXE 6, 421 (1996).
(48) Q. X. An, X. C. Zhan, Z. Y. Chao, Y. R. Wu, Y. N. Xiao,
and J. X. Pan, Nucl. Instr. and Meth. A 359, 295 (1995).
(49) T. D. Hu, Y. N. Xie, Y. L. Jin, and T. J. Liu, Phys.
Condens. Matter 9, 5507 (1997).
(50) Y. R. Wang, K. Q. Liu, and C. X. Li, Phys. Rev. Lett. 79,
3664 (1997).
(51) C. H. Hu, S. J. Liu, P. S. Liu, Z. H. Xia, G. H. Feng, andY. Yao, High Energ. Phys. Nucl. Phys. 23, 723 (1999) (inChai
Chinese).
(52) P. S. Liu, Q. Xu, and H. R. Shao, Intern. J. PIXE 6, 425(1996).
(53) Z. F. Chai, Fresenius J. Anal. Chem. 345, 93 (1993).
(54) X. Y. Mao and Z. F. Chai, ibid. 352, 174 (1995).
(55) C. S. Li, Z. F. Chai, X. L. Li, and X. Y. Mao, Geostand.
Newslett. 22, 195 (1998).
(56) X. L. Hou, C. S. Li, W. J. Ding, Q. F. Qian, and Z. F.
Chai, Fresenius J. Anal. Chem. 360, 423 (1998).
(57) X. L. Hou, Z. F. Chai, Q. F. Qian, and C. S. Li, IAEASM-344/6, 189 (1997).
(58) H. R. Shao and Q. Xu, Nucl. Instr. and Meth. B 104, 201(1995).
(59) Q. Xu, H. R. Shao, Q. F. Qian, P. Liu, and N. Q. Liu,
Intern. J. PIXE, 6, 405-408 (1996).
(60) P. Q. Zhang, Z. F. Chai, X. L. Lu, Q. F. Qian, and W. Y.
Feng, in Environmental Biomonitoring, Exposure
Assessement and Specimen Banking, ACS Symposium
Series 654, edited by K. S. Subramanian and G. V. Iyengar(Am. Chem. Soc., Washington, D. C., 1997), p.271.