ISSN:0049-8246    

DOI:10.1002/xrs.1300050213

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY

ISSN:0049-8246    

DOI:10.1002/xrs.1300050214

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY

ISSN:0049-8246    

DOI:10.1002/xrs.1300050216

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY

ISSN:0049-8246    

DOI:10.1002/xrs.1300050217

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY

ISSN:0049-8246    

DOI:10.1002/xrs.1300050218

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY

ISSN:0049-8246    

DOI:10.1002/xrs.1300050202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY

摘要:

AbstractTrace element analysis of geological samples by X‐ray fluorescence analysis presents certain difficulties such as possible line interferences, problems of sample preparation and of mathematical corrections for mass absorption and these are discussed. Analytical methods and results concerning nineteen silicate rock and mineral standards are give

ISSN:0049-8246    

DOI:10.1002/xrs.1300050203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY

摘要:

AbstractFolding aerosol loaded filters in two with the loaded side inwards during the X‐ray analysis not only reduces possible filter heterogeneity effects and improves sample protection, but also increases the sensitivity and renders filter paper absorption corrections simple and more accurate in many instances. It is shown that folding an aerosol loaded Whatman filter paper during Kα X‐rays counting leads to an increased sensitivity for all elements up from calcium, scandium or titanium (depending on the sensitivity definition and on the aerosol load) and for all elements up from phosphorus, sulphur or chlorine in the case of the Nuclepore filter. Although the absorption by the filter, into which the aerosol penetrates to some extent, is always more important in the sandwich than in the usual geometry, the dependence of the absorption correction on the usually unknown average deposition depth is less pronounced. Assuming all the aerosol material to be collected at the very surface of the filter and hence being present in the centre of the sandwich to be analysed, leads to an extremely simple filter paper absorption correction which is less prone to uncertainties than more sophisticated corrections in the usual geometry requiring additional measurements. This is the case for all elements up from potassium on Whatman filters and up from phosphorus on Nuclepore fil

ISSN:0049-8246    

DOI:10.1002/xrs.1300050204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY

摘要:

AbstractA rapid procedure for the accurate determination of Cl, SO4, K and Ca in brines has been developed. The brine sample as received is put into a liquid sample holder and analysed by the PW 1410 X‐ray spectrometer with a helium attachment. The data are processed by an on‐line desk calculator HP 9830A. The elements mentioned strongly influence each other's X‐ray intensities and, consequently, matrix corrections have to be applied. The influence coefficients used for corrections are derived from physical data and give excellent results in that all calibration equations are perfectly linearized. The two instrument‐dependent calibration constants for each element are very stable in time and agree well between our three instruments of the same type. This stability is ensured by applying a monitor standard (pressed powder); thus, the occasional recalibration work is minimized. The precision for each element is better than 0.4% relative at a 95% confidence level and for a measuring time of about forty seconds per element. The calculated concentrations are in weight fractions, which are finally transformed to grams/litre or equivalents/litre. The specific gravity required for this transformation is calculated from the weight fr

ISSN:0049-8246    

DOI:10.1002/xrs.1300050205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY

摘要:

AbstractThe subject of a monochromatic radiation strictlyequivalentto a given polychromatic spectral distribution is developed in accordance with usual analytical practice (e.g. by referring torelativeintensities) assuming that (1) the polychromatic distribution can be any one, i.e. a continuous or discontinuous white spectrum, possibly including characteristic lines or not; (2) the fluorescent element is engaged in a homogeneous sample and is subject only to pure absorption effects (whether positive or negative) on the part of its neighbour elements. Important conclusions can then be derived.These are (a) the existence for each composition of one, and only one, equivalent wavelength λe,the origin and mathematical determination of which are accurately described; (b) the fact that λesystematically decreases with increasing fluorescent element concentration in binary compositions, whatever the associate element, whether it be a positive or negative absorber. This property then clearly extends to anygivenmatrix; (c) the existence of a simple relation of equivalence between absorbers, enabling us to consider any absorber and then any absorbing matrix in terms of ‘equivalents’ if we so choose; (d) as a consequence of (b) and (c), a novel description of influence coefficients for the absorption case, accounting for their systematic variation with fluorescent element concentration and introducing a definite correlation between coefficients belonging to different absorbers; (e) further interesting properties such as the effect of the ‘geometry’, as well as the effect of dilution, on the situation of equivalent wavelengths and the values of influence coefficients. In so far as absorption effects are considered all the facts of X‐ray fluorescence as induced by polychromatic excitation are covered by the pre

ISSN:0049-8246    

DOI:10.1002/xrs.1300050206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY