In order to determine thorium and uranium traces in geochemical and cosmochemical samples, we developed an ICP-MS procedure, in which an anion-exchange step was introduced after sample digestion to separate major matrix elements, leading to decrease the dilution factor and increase the sensitivity for Th and U. The ICP-MS procedure was compared to the RNAA procedure which we recently developed for the same purpose. Both ICP-MS and RNAA procedures developed were found to yield similar detection limits (sub ppb) for Th and U.
The concentrations of extractable organohalogens (EOX) and extractable persistent organohalogens (EPOX) in placenta, umbilical
cord and hair of mothers delivering disabled or normal newborns as well as the compositions of EPOCl in three analyzed matrices
were determined by a combination of NAA, gas chromatography and chemical separation. The results indicated that both EOX and
EPOX decreased in the order: hair > umbilical cord > placenta. Organochlorines were the major fraction of organohalogens.
More than 77% of EPOCl were unidentified. High organohalogens exposure may induce adverse health effects, and hair, as a biomonitor
for organohalogens assessment, is more recommendable.
Authors:Z. Zhang, J. Yang, H. Ouyang, Z. Li, Z. Chai, J. Zhu, J. Zhao, Z. Yu, and J. Wang
Sixty-two heroin samples were analyzed for their contents of 15 trace elements (Au, Ba, Br, Ca, Ce, Co, Cr, Fe, La, Na, Sb,
Sc, Sm, Th, and Zn) by neutron activation analysis (NAA). Large variations of elemental concentrations between samples were
found to possess statistical significance. Of all the elements calcium was the most abundant element, followed by zinc and
sodium. The concentrations of Au, Ce, Co, La, Sb, Sc, Sm, and Th in all the samples were below 1 mg·g−1. Classification of these heroin samples was achieved by the application of hierarchical cluster analysis. The results show
that NAA can provide useful information on the origin of the illicit drugs.
Authors:H. Zhang, Z. Chai, H. Sun, J. Zhang, H. Ouyang, L. Xin, and Y. Chuai
The concentrations and distributions of total halogen (TX), extractable organohalogen (EOX) and extractable persistent organohalogen
(EPOX) were determined in 20 kinds of yogurt specimens collected from Chinese supermarkets using neutron activation analysis
(NAA) and gas chromatography equipped with a 63Ni electron capture detector (GC-ECD). The results indicated that the halogens in yogurt mainly existed as non-extractable
organohalogen compounds. About 25–30% of EOX was EPOX. EOCl and EPOCl were the main organohalogen species in yogurt. The average
concentration of the identified organochlorine, such as organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs),
was below 4% of EPOCl.
Authors:J. Chai, Y. Miyamoto, Y. Kokubu, M. Magara, S. Sakurai, S. Usuda, Y. Oura, and M. Ebihara
In order to search for isotopic anomalies of U caused by the disintegration of 247Cm in meteorite samples, an analytical scheme for determining 235U/238U ratio for a small amount of uranium (less than 1 ng U) was established. The isotopic ratio of U was determined by double-focusing
inductively coupled plasma mass spectrometry (DF-ICP-MS). With a great improvement of chemical procedure for purifying the
uranium fraction separated from meteorite samples, a variation in 235U/238U ratios was resolved at an order of ±4‰ for 100 ppt or 200 pg U in solution. For applying the procedure in searching an evidence
of 247Cm as an extinct radionuclide in the early solar system, a selective chemical dissolution of constituent minerals of meteorites
using EDTA and HCl was introduced and a chemical purification scheme of uranium for ICP-MS was established.
Authors:F. Zhang, W. Feng, J. Shi, M. Wang, Y. Huang, W. He, and Z. Chai
The damage in the pup rat brain with low-level mercury exposure, and the concentration variation of trace elements in the
rat hippocampus was determined by synchrotron radiation X-ray fluorescence technique (SRXRF). Meanwhile, the levels and activities
of glutathione (GSH), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA)
in the hippocampus were also measured. The results showed that the low dose of inorganic mercury prenatal and postnatal exposure
could lead to the significant increase of both copper and zinc contents and remarkable decrease of iron content in pup rat
brain. Compared to the control group, the activities of antioxidant enzymes such as GSH-Px, SOD, the contents of GSH and MDA
in the pup rat hippocampus of mercury-exposed group fell down obviously.
Authors:S. Hu, Z. Chai, X. Mao, H. Oy, H. Wang, J. Zhang, and Y. Huang
Neutron activation analysis (NAA) and synchrotron radiation X-ray fluorescence analysis (SRXRF) were used to study the loss
and recuperation of inorganic elements of osteoporotic rat bone and the effects of Zhugu Capsule. The results of the animal
experiments showed that there was greater loss of multiple elements in cancellous bone than in cortical bone that was difficult
to be improved. Yet in the mid-shaft femur, which is mainly consisted of cortical bone, the contents of multiple elements
were notably recuperated. Zhugu Capsule could increase the content of not only of Ca, but also Zn and Sr. Further, it could
also improve the distribution of these elements in femur.
Authors:X. He, Z. Zhang, L. Feng, Z. Li, J. Yang, Y. Zhao, and Z. Chai
After an acute exposure to lanthanum chloride, the pharmacokinetics of calcium uptake in rats was studied by radioactive 47Ca tracer. The accumulated doses of calcium in the left femurs during 24 hours were determined. The results showed that the
area under the curves (AUC), specific activity of maximal blood 47Ca concentration (Cmax), distribution rate constant (Ka) and the accumulated dose of calcium in the left femur decreased while time to Cmax (Tpeak) increased with the rising dosage of lanthanum exposure. It indicated that lanthanum expose had a negative effect on calcium
Authors:Q. Qian, W. Feng, J. Chen, P. Zhang, C. Chai, J. Pan, Y. Wu, S. Zheng, X. Liu, and Z. Chao
The iron contents in the hair and blood samples of 37 juvenile athletes who were supplemented with 0, 8 and 16 mg Fe/day, respectively, in the food of ferrous gluconatecontaining chocolate for 3 months were determined before and after the supplementation by INAA, SRXRF and blood analysis. The experimental results showed that after supplementation of the iron-fortified food, the normal ferritin level in the blood of the male athletes was attained and the iron content in the hair was increased with supplementation, but both are not in the positive proportion. Most of the female athletes had similar results. It is suggested that supplementation of 8 mg iron/day to juvenile athletes may be desirable.
Authors:J. Wang, C. Chen, H. Yu, J. Sun, B. Li, Y. Li, Y. Gao, W. He, Y. Huang, Z. Chai, Y. Zhao, X. Deng, and H. Sun
The characterization of different sized TiO2 (25 nm, 80 nm, and 155 nm) was carried out by transmission electron microscopy (TEM) and the micro-distributions of TiO2 in the olfactory bulb of mice after nasal inhalation were investigated by microbeam SRXRF mapping techniques. The results
show that TiO2 particles can be translocated to the olfactory bulb through the olfactory nerve system after inhalation. The distributions
of Fe, Cu, and Zn in the olfactory bulb were also studied.