共查询到20条相似文献,搜索用时 15 毫秒
1.
Vassileva Emilia Azemard Sabine Mandjukov Petko 《Accreditation and quality assurance》2018,23(1):29-37
Accreditation and Quality Assurance - Marine sediment certified reference material (CRM), IAEA-456 was recently produced by the Environment Laboratories of the International Atomic Energy Agency... 相似文献
2.
E. Cortés N. Gras L. Muñoz V. Cassorla 《Journal of Radioanalytical and Nuclear Chemistry》1982,69(1-2):401-415
Seven trace elements were determined in milk formulas, powder milk and infant food. Instrumental neutron activation analysis
was used for the analysis of Fe, Zn, Co, Cr and Rb, while As and Cu content was determined using radiochemical neutron activation
analysis. Differences were found in the trace element content of foods of the same type. Milk formulas are comparable with
human milk according to the results obtained for the elements analyzed. The samples of powder cow's milk presented similar
concentrations of the elements studied. Liver with vegetables was found to have the highest Cu content. A meal prepared at
home, made of beef and fresh vegetables showed a higher trace element content than its similar commercial one. An estimation
of the daily intake of the elements analyzed was made and compared with minimum recommended daily ingestion. 相似文献
3.
K. Kostic R. J. Draškovic M. Ratkovič D. Kostić R. S. Draškovic 《Journal of Radioanalytical and Nuclear Chemistry》1977,37(1):405-413
In our biological investigations some trace elements have been determined by instrumental radioactivation analysis in organs
of normal rats. The results of trace element distribution of Cr, Zn, Br, Sb, Fe, Co, Sc, Ag and Na in liver, spleen, brain,
lung, kidney and heart of normal rats are presented in the paper. 相似文献
4.
K. B. Dasari R. Acharya N. Lakshmana Das 《Journal of Radioanalytical and Nuclear Chemistry》2013,298(1):699-705
The paper presents the chemical composition analysis results of 57 ancient clay bricks obtained from Buddhist sites of two major locations of Andhra Pradesh, India. Samples were analyzed by instrumental neutron activation analysis (INAA) using high flux reactor neutrons and high resolution gamma ray spectrometry. Major, minor and trace concentrations of 23 elements were determined by relative method of NAA. For the grouping/provenance study, statistical cluster analysis was performed using concentrations of 14 selected elements namely Sc, Cr, Fe, Co, Zn, Cs, La, Ce, Eu, Tb, Yb, Lu, Ta and Th. The cluster analysis results indicated two major groups, which are in good agreement with the collection history of samples. Accuracy of the method was evaluated by analyzing two IAEA reference materials, RMs SL-1 and Soil-7. 相似文献
5.
Quan Jin Like Gong Shaoying Liu 《International journal of environmental analytical chemistry》2017,97(10):983-1002
A method for simultaneously determining the trace elements in particulate matter (PM) (PM2.5) by inductively coupled plasma mass spectrometry was established. The PM2.5-loaded filter samples were digested under the optimised conditions including a mixture of HNO3–HCl–HF with ultrasonication proceeding at 70°C for 2 h. Recoveries of 90.83–103.33% were achieved for 20 elements (Co, Sr, Ag, Cd, Sb, La, Ce, Sm, W etc.) in NIST standard reference material 1648a (urban PM). PM2.5 samples were collected at urban site in Hangzhou from August 2015 to November 2015. PM2.5 concentrations of 15% sampling days exceeded the daily limitation and the mean concentrations of PM2.5 from August to November reached the 66.4% of the limitation. PM2.5 concentrations in summer were higher than that in autumn. The concentration of Zn was highest, following with Al, Pb, Mn, Cu and As. Significant enrichment was observed in Mn, Zn, Pb, Ag, V, Ni, Cu, As, Se, Hg, Co, Cd and W, which was probably induced by vehicular exhaust, oil and residual fuel combustion and industrial emissions. The daily mass concentrations of PM2.5 and elements fluctuated significantly. Rainfall could significantly reduce the concentration of Ti, Mn, Cu, Zn, As, Se, Hg, Sr, Ag, Cd, Sb, La, Ce, Sm and Pb, and the risk levels of carcinogenic elements and non-carcinogenic elements in rain day were significantly lower (43.7–81.4%) than those in non-rain day. The risk levels of Co, Cd and As could lead to adverse health outcomes through the respiratory system, which should deserve more attention, while the risk levels of Ni and non-carcinogenic elements (Hg, Mn, Cu, Zn, Pb, V) were under average risk acceptance. 相似文献
6.
C. Sola-Larrañaga 《Analytica chimica acta》2006,555(2):354-363
The concentrations of minerals (Na, K, P, Ca and Mg) and trace elements (Fe, Zn, Cu, Mn, Se, Al, Cd and Pb) in a total of 105 different infant formulae (starter, follow-up, premature, specialised and soya formulae) marketed in Spain were determined by atomic spectrometry (flame and electrothermal) and inductively coupled plasma emission spectroscopy after acid-microwave decomposition. On the basis of the elements distribution, a preliminary chemometric study with the use of pattern recognition methods was carried out. Hierarchical cluster analysis (HCA), principal component analysis (PCA), as unsupervised exploratory techniques, and linear discriminant analysis (LDA), were applied to characterise, classify and distinguish the different types of infant formulae. The HCA results showed that mineral and trace element content data support adequate information to obtain the infant formula differentiation. PCA permitted the reduction of 13 variables to four principal components accounting for 61.9% of the total variability. This four-factor model interprets reasonably well the correlations of these studied elements. The obtained element associations may be attributed to the composition of matrix ingredients, the contamination during elaboration, the additives and mineral supplements added and the present tendency of standardization in the manufacture of infant formulae. The application of LDA gave a 77.1% of infant formulae correctly assigned with three clearly differentiated and two overlapped groups. The use of discriminant functions, as a complementary tool, to distinguish the different types depending on protein matrix of infant formula, is also discussed. This survey shows that HCA, PCA and LDA techniques appear useful tools for the characterisation and classification of infant formulae using their elemental profile. 相似文献
7.
E. Vasileva S. Azemard J. Oh P. Bustamante M. Betti 《Accreditation and quality assurance》2011,16(8-9):439-447
A marine certified reference material (CRM), IAEA-452, prepared with scallop (Pecten maximus) sample was recently produced by the International Atomic Energy Agency (IAEA) and certified for trace elements and methyl mercury (MeHg). The Scallop (Pecten maximus) sample is commonly found and consumed seafood and is also used as bio-indicators for trace metal contamination in marine pollution studies. This paper presents the sample preparation methodology, material homogeneity and stability studies, evaluation of certification campaign results, the assignment of property values and their associated uncertainty. The reference values and associated expanded uncertainty for 9 trace elements (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb and Zn) and MeHg in scallop sample are established. The informative value for one more element (Ni) is also given. The new CRM can be used for the development and validation of analytical methods for determination of trace elements and methyl mercury in seafood and also for quality assurance/quality control purposes. 相似文献
8.
9.
The trace element levels in various organs of normal rats have been determined by means of thermal neutron activation followed
by high-resolution gamma-spectroscopy. Abundances for 11 elements (Cu, Mn, Fe, Zn, Rb, Sb, Se, Cr, Co, Cs and Sc) were evaluated
in the individual subjects. The present results were generally found within the ranges of the literature values, except for
ultra-trace elements. Reliability of the method was assessed by analyzing NBS standard reference materials, Orchard Leaves
and Bovine Liver. The trace element contents of the rat diet have also been measured, and comparison of them with those of
the rat organs was given. 相似文献
10.
Two samples of Napoleon's hair were received for determination of arsenic, mercury and other trace elements by INAA. Before sample irradiation, the hairs were washed following the IAEA washing procedure. Two standard reference materials of GBW09101 (human hair) and NIST/SRM1572 (citrus leaves) were analyzed along with Napoleon's hair for quality control. Standardization was conducted by applying the k
0-method implemented in the program MULTINAA. The contents of arsenic and mercury as well as three additional elements chromium, antimony and zinc in Napoleon's hair are reported. Compared to the present normal levels, all of the determined elements in Napoleon's hair, except the mercury, are found to be irregular. 相似文献
11.
Summary A preconcentration technique involving anion-exchange in a thiocyanate medium has been developed for the determination of traces of vanadium, cobalt, copper, zinc, and cadmium in sea water. A conventional, small column containing a strongly basic anionexchange resin Amberlite CG 400 in the thiocyanate form allows the five trace metals to be concentrated from a 11 of sea water sample adjusted to 0.1M in thiocyanate and 0.1M in hydrochloric acid. Sorbed metals can be recovered simultaneously by elution with 140 ml of 2M perchloric acid. A stepwise elution technique is also developed, which permits removal of vanadium-copper-cobalt as a group, zinc, and cadmium to improve the selectivity of the separation. A simple scheme of separation for vanadium, copper, and cobalt is given, so that spectrophotometric determinations of these metals even with nonselective reagents may be feasible. Results are quoted on the preconcentration and subsequent spectrophotometric determination of the five metals in brine and sea waters. 相似文献
12.
Determination of trace elements in wines and classification according to their provenance 总被引:2,自引:0,他引:2
Thiel G Geisler G Blechschmidt I Danzer K 《Analytical and bioanalytical chemistry》2004,378(6):1630-1636
Provenance and authenticity of wines can be recognized on the basis of typical mineral and trace element patterns by means of chemometric methods. Therefore analytical methods were developed for the determination of As, Be, Co, Cs, Ga, Li, Nb, Ni, Rb, Te, Ti, W, Y, and Zr as well as Mo, Cd, Sb, Tl, U, and the rare earth elements in wines by inductively coupled plasma mass spectrometry (ICP-MS). For low risk of contamination or loss of analyte as well as depletion of sample amount and an easy sample pretreatment, direct measurement of diluted wines was studied. The accuracy of the analytical results was proven by recovery experiments by method comparison with standard addition methods and measurement of digested wines. In addition to applying statistical methods for characterizing the precision of the methods, the uncertainty of the measurements was estimated.Results for the elements mentioned above and additional 16 elements (Al, B, Ba, Ca, Cr, Cu, Fe, Mn, Mg, P, Pb, Si, Sn, Sr, V, and Zn) were evaluated by data analytical methods. Due to a specific choice of the analytes for multivariate statistical investigation a prediction rate by cross validation of 88.6% could be achieved. 相似文献
13.
14.
Zheng Jian Zhuang Guisun Wang Yongji Dong Mo Zhang Fulin 《Journal of Radioanalytical and Nuclear Chemistry》1992,166(2):97-107
The concentrations of up to 11 elements in subcellular fractions of human brain (normal and malignant tumor) have been determined by a combination of gradient centrifugation and INAA methods. Samples of human brain were homogenized in a glass homogenizer tube, the homogenate was separated into nuclei, mitochondrial, myelin, synaptosome fractions, and these fractions were then analyzed using the INAA method. The discussions of elemental subcellular distributions in human brain malignant tumor are presented in this paper. 相似文献
15.
Yamasaki K Sakuma Y Sasaki J Matsumoto K Anzai K Matsuoka K Honda C Tsukada M Endo K Enomoto S 《Analytical and bioanalytical chemistry》2011,401(8):2531-2538
The excretion of essential trace elements, namely, Se, Sr, As, Mn, Co, V, Fe, and Zn into the bile of Se-deficient (SeD) Wistar
male rats was studied using the multitracer (MT) technique, and instrumental neutron activation analysis (INAA). Normal and
Se-control (SeC) rat groups were used as reference groups to compare the effects of Se levels on the behaviors of the essential
trace elements. The excretion (% dose) of Se, Sr, As, Mn, Co, and V increased with Se levels in the liver. The biliary excretion
of Mn and As dramatically enhanced for SeC rats compared with SeD rats, while that of V accelerated a little for SeC rats.
The radioactivity levels of 59Fe and 65Zn in the MT tracer solution were insufficient to measure their excretion into bile. The role of glutathione and bilirubin
for biliary excretion of the metals was discussed in relation to Se levels in rat liver. 相似文献
16.
E. Ivanova N. Jordanov I. Havezov M. Stoimenova S. Kadieva 《Fresenius' Journal of Analytical Chemistry》1990,336(6):501-502
Summary A method is described for the determination of 20 trace elements in gold of a qualification of about 4–5 N. The matrix is separated by solvent extraction into methylethylketone/chloroform and the trace elements are determined in the aqueous phase by AAS (flame or graphite furnace). The procedure is optimized as to minimize the number of contamination sources. 相似文献
17.
A method is described for the determination of cadmium, cobalt, copper, manganese, lead, uranium, and zinc in samples of natural waters. After acidification with hydrochloric acid the water sample is filtered and the diethyldithiocarbamates of the trace elements are isolated by extraction with acetone—chloroform (2:5) at pH 5. Following this preconcentration step the metal ions are adsorbed on a column of the strongly basic anion-exchange resin Dowex 1-X8 (chloride form) using as sorption solution a mixture (5:4:1, ) of tetrahydrofuran, methyl glycol and 6 M hydrochloric acid. Successive elution is effected with 6 M hydrochloric acid (Co, Cu, Mn and Pb), 1 M hydrochloric acid (U) and 2 M nitric acid (Cd and Zn); the metal ions in the eluates are determined by atomic absorption spectrophotometry (except uranium, which is determined fluorimetrically). The procedure was used to determine the trace-metals in water and snow samples collected in Austria and to analyse a sample of sea water from the Adriatic Sea. 相似文献
18.
L. Kempenaers C. De Koster W. Van Borm K. Janssens 《Analytical and bioanalytical chemistry》2001,369(7-8):733-737
BCR CRM 680 is a newly released reference material (RM) with a polyolefinic matrix, doped with various metallic compounds in trace concentrations, to be used for calibration of multi-element trace analytical methods. The micro-heterogeneity of this new CRM was investigated to evaluate the suitability as a RM for trace-level micro analytical techniques. Synchrotron μ-XRF, a trace-level micro analytical method, allows to quantitatively measure the degree of heterogeneity of inorganic trace constituents in solid materials with a homogeneous matrix. The procedure for calculating the minimal sampling mass for homogeneous measurements was employed for BCR CRM 680. By repeating the entire procedure on several samples of the same material, the repeatability of the micro-heterogeneity characterization based on μ-XRF was investigated. Afterwards, the micro-heterogeneity results from the BCR CRM 680 material were used to evaluate the suitability of the micro-heterogeneity procedure by means of a Monte Carlo simulation model. Also the existence of nuggets in the polymer material is looked into. 相似文献
19.
Kempenaers L De Koster C Van Borm W Janssens K 《Fresenius' Journal of Analytical Chemistry》2001,369(7-8):733-737
BCR CRM 680 is a newly released reference material (RM) with a polyolefinic matrix, doped with various metallic compounds in trace concentrations, to be used for calibration of multi-element trace analytical methods. The micro-heterogeneity of this new CRM was investigated to evaluate the suitability as a RM for trace-level micro analytical techniques. Synchrotron micro-XRF, a trace-level micro analytical method, allows to quantitatively measure the degree of heterogeneity of inorganic trace constituents in solid materials with a homogeneous matrix. The procedure for calculating the minimal sampling mass for homogeneous measurements was employed for BCR CRM 680. By repeating the entire procedure on several samples of the same material, the repeatability of the micro-heterogeneity characterization based on micro-XRF was investigated. Afterwards, the micro-heterogeneity results from the BCR CRM 680 material were used to evaluate the suitability of the micro-heterogeneity procedure by means of a Monte Carlo simulation model. Also the existence of nuggets in the polymer material is looked into. 相似文献