The internal standard method coupled with the standard addition method has been applied to the analysis of environmental materials, such as urban particulate matter, vehicle exhaust particulates and coal fly ash by photon activation. High-resolution gamma-ray spectrometry makes possible to use multi-internal standard gamma-rays, in order to crosscheck the analytical results obtained from each internal standard. It was ascertained that this method can provide not only accurate analytical results but also the information of homogeneity of samples, correlation of elements in the sample, loss or contamination in the preparation process.
The elemental concentration of the ceramic standard material F, G, H, J and K of the Centre de Recherches Archéologiques Médiévales,
Université de Caen have been determined based upon the Perlman/Asaro Standard. The analysis has been done by instrumental
neutron activation analysis. Results are given for Fe, Na, K, Ba, Co, Cr, Cs, Eu, Ga, La, Lu, Mn, Rb, Sc, Ta, Yb.
Two sets of calibration standards for134Cs and137Cs were prepared by small serial dilution of a natural matrix standard reference material, IAEA-154 whey powder. The first set was intended to screen imported milk powders which were suspected to be contaminated with134Cs and137Cs. Therefore the concentration range of the calibration standards were about 40–400 Bq/kg. The precision of the preparation of the standard with about 7 Bq/kg of134Cs and 39 Bq/kg of137Cs at measurement time was 7.4% and 3.2%, respectively. The preparation of a similar standard by spiking the matrix with radioisotope solutions resulted in a poorer precision, about double that of the former technique. The other set of calibration standards was prepared to measure the environmental levels of137Cs in commercial Venezuelan milk powders. Their concentration ranged from 3–10 Bq/kg of137Cs. The accuracy of these calibration curves was checked by using IAEA-152 and A-14 milk powders. Their measured values were in good agreement with their certified values. Finally, it is shown that these preparation techniques by serial dilution of a standard reference material were simple, rapid, precise, accurate and cost-effective.
Authors:D. Leypunskaya, V. Drynkin, B. Belenky, M. Kolomi'tsev, V. Dundua, and N. Pachulia
Complex (multielemental) standards representing microelement composition of standard rocks such as trap ST-1 (USSR), gabbrodiorite
SGD-1 (USSR), albitized granite SG-1 (USSR), basalt BCR-1 (USA) and granodiorite GSP-1 (USA) have been synthesized. It has
been shown that the concentration of each microelement in the synthetic standards can be given with a high precision. Comparative
investigation has been carried out of the synthetic imitations and the above natural standard rocks. It has been found that
the result of the instrumental neutron activation analysis using the synthetic standards is as good as in the case when natural
standard rocks are used. The results obtained have been also used for substantiation of the versatility of the method used
for standard preparation, i.e. a generalization has been made of a possibility of using this method for the preparation of
synthetic standards representing the microelement composition of any natural rocks with various compositions and concentrations
Authors:P. Krey, M. Feiner, C. Sanderson, J. Mcinroy, K. Inn, and J. Hutchinson
A bone ash standard for a number of radionuclides is required as a quality control sample in dosimetry studies with bone as the critical organ. The procedures that were used to prepare a candidate bone ash standard are given with some initial encouraging measurements that the candidate sample will meet the requirements of NIST standard reference manual.
Experimental verification of the formalism using nonidentical samples and standards in 14 MeV neutron activation analysis
has been carried out. A standard was used containing the same element as the matrix; however its geometrical form is completely
different. The formalism used yields satisfactory results even when the sample and the standard are counted at different distances
from the detector.
A procedure for monostandard INAA of 21 elements (Hg, As, Br, Cr, Sb, Se, Ba, Zn, Ca, Ce, Co, Cs, Eu, Fe, Hf, K, La, Rb, Sc, Sr, Ta) in Chinese Biological Standard Reference Material (peach leaves) is described. The accuracy of the procedure was checked by analyzing the U.S. NBS Standard Reference Materials SRM-1571 and SRM-1632a.
Authors:J. Rouchaud, L. Debove, M. Fedoroff, L. Mosulishvili, V. Dundua, N. Kharabadze, N. Shonia, E. Efremova, and N. Chikhladze
An aluminium matrix and a phenolformaldehyde polymer were tested as base materials for multielement standards resistant to high neutron doses in activation analysis. Interlaboratory analyses showed that these standards can be certified for the concentrations of the majority of introduced elements.
Instrumental neutron activation analysis (INAA) was used for the determination of 23 elements and prompt gamma neutron activation analysis (PGNAA) was used for the determination of 10 elements in U.S. National Bureau of Standards (NBS) 1633A Fly Ash Standard Reference Material (SRM). The results are in excellent agreement with the limited number of NBS certified values available.