摘要:

Results of the measurement of uranium in silicate reference materials on the same samples at two different facilities, both using delayed neutron activation analysis, are compared. Good agreement was observed between the results of our two laboratories. Discrepancies have been observed occasionally between different laboratories which utilize delayed neutron activation analysis. On the basis of the results observed in this work, we conclude that discrepant results are not due to variations in the physical facilities of the laboratories.

ISSN:0150-5505    

DOI:10.1111/j.1751-908X.1982.tb00337.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Radium‐226 concentrations have been determined in 11 CCRMP reference rock and ore samples using instrumental gamma‐ray spectrometry and radiochemical radon emanation procedures. Results are compared to the best available d

ISSN:0150-5505    

DOI:10.1111/j.1751-908X.1982.tb00338.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Instrumental epithermal neutron activation analysis and delayed neutron assay have both been used to measure uranium in CRPG reference samples. Excellent agreement between the methods was achieved. Results are compared with data from other laboratories.

ISSN:0150-5505    

DOI:10.1111/j.1751-908X.1982.tb00339.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Two new carbonate isotope standards have been prepared for distribution by the IAEA and NBS. The first, TS limestone, NBS #19, will substitute for PDB, while the second carbonate, NBS #18 is depleted in18O and13C compared to the first.

ISSN:0150-5505    

DOI:10.1111/j.1751-908X.1982.tb00340.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Standard reference material of fluorite FM, consisting chiefly of fluorite, quartz and baryte, was prepared by the Institute of Mineral Raw Materials in Kutná Hora (Czechoslovakia). The homogeneity of the pulverised SRM was checked by X‐ray fluorescence spectrometry from counts corresponding to the amounts of iron, copper, barium, strontium and titanium. The SRM was considered homogeneous if the “between bottles” variance was not significantly greater than the “within bottles” variance and further, if the error caused by heterogeneity of the SRM was less than one third of the error of an analytical determination carried out in a routine manner. Analytical results from 26 laboratories were processed following the recommended procedure of CMEA‐countries which includes: Testing the normality of results, eliminating out‐lying results and computing the arithmetic means, estimates of standard deviations and the confidence intervals of the means. Attested values for 17 components and non‐attested values for 30 components and/or eleme

ISSN:0150-5505    

DOI:10.1111/j.1751-908X.1982.tb00341.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The effect of the between‐ and within‐laboratory standard deviation and of the number of laboratories on the magnitude of the certification factor, CF, introduced in 1975 by the Canadian Certified Reference Materials Project (CCRMP) has been discussed. The applicability of CF to reference materials has been assessed on the basis of the correlation between the between‐ and within‐laboratory standard deviation. The validity of the critical value of 4 for CF for certifiability is examined.An examination of all available data has led to the conclusion that the quality of an interlaboratory program is sufficient to warrant certifiability only if the ratio of the between‐to the within‐laboratory standard deviation is 3 or less for most elements and 2 or less for uranium. It has been shown that the number of laboratories rejected based on the upper limit of this ratio differs only slightly from that based on laboratory means differing by more than twice the standard deviation of the overall mean for the majority of elements that have been certified. A new measure for assessing the certifiability of an element has been introduced and is based on the requirement that the percentage of laboratories that are rejected to give a ratio of the between‐ to within‐laboratory standard deviation less than or equal to the critical value of 3 or, for uranium, 2 should be no greater than 15% regardless of the number of laboratories in the certif

ISSN:0150-5505    

DOI:10.1111/j.1751-908X.1982.tb00342.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The mercury contents of 109 reference samples of 12 organizations have been determined by flameless atomic absorption spectrometry. The homogeneity of mercury in the six USGS samples issued in 1964 was tested twice, a year apart, using unopened bottles of samples. The analysis of variance of these data in the form of a design with a single variable of classification showed that the mercury contents of the 12 sets can be considered homogeneous at F0.95and that 10 of these sets can be considered homogeneous at F0.90, a more stringent test.Data for other reference samples were generally obtained using Youden Squares. This experimental design was used so that we could determine the significance of the variation attributable to some cause on the days on which mercury was determined, to the order in which the determinations were made on the several days, and to the mercury contents of the samples in each design. For the latter, one may assume that the mercury contents of samples will differ and that a significant F ratio may be obtained. For the principal variable of classification, the variation attributable to some cause on the days on which mercury was determined was significant for only 1 of 9 analyses of variance of sets of data but we have not been able to explain the cause of the significance.The mercury contents of the several types of samples, except for micas, dunites, and perhaps the granodiorites, depend on the origin of the samples. The mercury contents of ande‐sites and basalts of continental origin are higher than those for similar samples originating in island arcs or the circum‐Pacific belt. We conclude that the high and extremely variable mercury content of W‐1 is probably due to mercury resulting from the use of mercury fulminate detonators in the quarry prior to the collection of the s

ISSN:0150-5505    

DOI:10.1111/j.1751-908X.1982.tb00343.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

“Usable values” based on evaluation by the “select laboratories” method are presented for concentrations of many constituents of eight reference rocks from the U.S. Geological Survey. Comparisons are made between the derived values and those published

ISSN:0150-5505    

DOI:10.1111/j.1751-908X.1982.tb00344.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The tin contents of 73 geochemical reference samples have been determined by atomic absorption spectrometry using an argon‐hydrogen flame after extraction of tin (IV) as iodide with benzene. The agreement between the present results and published data is generally goo

ISSN:0150-5505    

DOI:10.1111/j.1751-908X.1982.tb00345.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

This paper reports an investigation into the suitability of the neutron‐activation method, by use of the reaction238U(n,γ)239U with detection of the gamma‐rays from the daughter239Np, for the determination of uranium in 10 proposed reference materials.182Ta was used to monitor the neutron flux. The precision of measurement varied from 0.92 to 2.7 per cent. Results compare favourably with those obtained by other analytical procedures, and show that this established method can be used to yield useful and independent results in the preparation of uranium reference mater

ISSN:0150-5505    

DOI:10.1111/j.1751-908X.1982.tb00346.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY