A total of 178 aerosol samples in two size fractions, PM10-2.5 (coarse) and PM2.5 (fine), were collected on nucleopore films
using a Gent stacked filter unit sampler at the Graduate School of China Nuclear Industrial Group during May 2007 to November
of 2009. Black carbon was determined by a reflectometer. A total of 16 elements, Mg, Al, S, Si, P, Cl, Ca, K, Ti, Mn, Fe,
Ni, Cu, Zn, As and Pb, were determined by Particle Induced X-ray Emission. Mg, Al, Ca, K and Mn were also determined by Neutron
Activation Analysis. Concentrations of all these elements were used to identify possible pollution sources and directions
of the airborne particulate matter by means of softwares PMF and CPF. Some extraordinary events, such as sandstorms, firework
and transboundary fire smoke were pinpointed by a combination of time series of multielement, relevant meteorological data
and softwares Wind rose, Hysplit, and Google earth.
China Advance Research Reactor (CARR) at China Institute of Atomic Energy (CIAE), with a non-perturbed maximum thermal neutron
flux of 1 × 1015 cm−2 s−1 at the center of active area, is one of the most powerful research reactors in the world. Three neutron channels have been
allocated for conventional neutron activation analysis (NAA), thermal neutron prompt gamma activation analysis (PGAA) and
cold neutron PGAA, respectively. Two irradiation tube systems are installed in the conventional NAA channel. One of them is
for short irradiation with the rabbit size of diameter (Φ)19 × 40 mm, the other one is for long irradiation with the rabbit
size of Φ39 × 70 mm. The medium temperature is about 45 °C and the thermal neutron flux is about 3 × 1014 cm−2 s−1 at sample positions. The flux gradient is expected to be very small according to the designed neutron flux distribution.
Pneumatic systems are used for samples transfer. The speed of rabbits is designed to be about 20 m/s, and it takes 3 s to
travel from irradiation position to detector. Three sets of gamma counting systems and one delayed neutron counting system
are being equipped for routine analysis. They are designed for running continuously and automatically. And all the functions
can be operated at laboratory or office through remote controlled computer. Software has been made domestically for spectrum
peak search, concentration calculation with relative method and k0 method with interference corrections and some other functions for the convenience of users.
Authors:Hai-Qing Zhang, Bang-Fa Ni, Wei-Zhi Tian, Gui-Ying Zhang, Dong-Hui Huang, Cun-Xiong Liu, Cai-Jin Xiao, Peng Nie, and Hong-Chao Sun
An expression of γ-ray efficiency for large samples is proposed based on numerical integration of efficiencies over compositional
point sources. The widely used expression on radial variation of HPGe efficiency for point source originally proposed by Noguchi
et al. (Int J Appl Radiat Isot 32:17–22, 1980 [<cite>1</cite>]) was amended and a new expression was proposed. A comparison between the two expressions indicates that the newly proposed
expression brings about an obvious improvement, and Self-absorption correction for a voluminous source is also given out by
using the EID principle. The functional relationship between HPGe efficiency for γ-rays from a point source and the spatial
position of the source was established. The results of this study can be applied in order to determine γ attenuation effects
of unknown bulky samples with various shapes and materials.
Twenty different brands of Chinese tea were analyzed for multiple trace elements, including some essential and toxic elements,
by neutron activation analysis (NAA). A comparison among tea brands from China, India, US and other countries was made for
the ranges and averages of concentrations for Na, K, Mn, Cu, and Br. It has been observed that the trace element contents
in tea leaves are largely dependent upon the soil and the environment where the tea grows. Chinese tea is rich in Mn and Cu
comparing with those of other counties surveyed, but is indigent in Na. The transference ratio for each element determined
(i.e., the fraction of an element in tea leave transferred into solution when tea is leached by percolation) is also reported.
Adult daily intakes of some essential and toxic elements from tea drinking were also estimated.
Authors:Huang Donghui, Sun Hongchao, Ni Bangfa, Tian Weizhi, Zhang Yuanxun, Wang Pingsheng, Liu CunXiong, Zhang Guiying, Xiao Caijin, Zhang Haiqing, and Zhao Changjun
Sampling behavior of multielements for NIST SRM 2703, a marine sediment, was studied with sample sizes from 1 mg down to ng
level by a combination of INAA, PIXE and SRXRF. On 1 mg sample size level, sampling behavior for multielements in NIST SRM
2703 and its parent SRM 2702 were comparatively characterized by using INAA combining with Ingamells model. Results showed
that sampling uncertainties for 12 elements of both materials were found to be better than 1%, and those of four other elements
in SRM 2703 better than in SRM 2702. At sample sizes not able to be accurately weighed (<1 mg), PIXE and SRXRF were used and
the effective sample sizes estimated. Sampling uncertainties for nine elements were found to be better than 1% at sample sizes
of tenth mg level, and those for six elements better than 10% on ng levels.
Taking advantages of nuclear analytical techniques (NATs) with non-destruction, multielement capability, small and estimable
uncertainties over a wide range of sample sizes, the sampling behavior of multielements for a home-made natural matrix material
was studied with sample sizes ranging from several hundred mg down to tenths ng, namely nine orders of magnitude, by a combination
of three NATs, neutron activation analysis (NAA), proton induced X-ray emission (PIXE) and synchrotron radiation X-ray flurescence
(SR-XRF), in an effort to explore a procedure for the development of certified reference materials (CRMs) suitable for quality
control of microanalysis. For accurately weighable sample sizes (>1 mg), sampling uncertainties for 13 elements were found
to be less than 1% by INAA. For sample sizes unable to be accurately weighed (<1 mg), PIXE and SR-XRF were used, respectively.
Sampling uncertainties were found to be less than 1% at sample sizes of tenth mg level for seven elements, and less than 10%
on ng levels for three elements. Considering these three elements have satisfied homogeneity (sampling uncertainty less than
10%) at ng sample size level, any one of them can be served as a “relative balance” in sampling behavior characterization
of multielements on sample size levels larger than ng (e.g., μg level). On this basis, sampling uncertainties for nine elements
were found to be less than 10% on μg sample size level by INAA. The results indicate that the matrix is eligible as a candidate
of CRMs suitable for quality control of solid sampling microanalysis.