On the application of Compton scattering to the elimination of matrix effects in non-dispersive X-ray fluorescence analysis

A new approach to solving matrix problems in x-ray fluorescence analysis of trace elements has been applied to the determination of bromine in saline waters and zinc in silicates. The method requires no prior knowledge of the chemical composition of the sample. Marked matrix effects are minimized by dilution, and the problem of variable backgrounds due to residual matrix effects is solved by using a slope-ratio technique. In this proposed technique, the slope of a standard curve prepared from pure solutions is compared with that of spiked samples. The ratio of the slopes of these two curves permits the calculation of an adjusted background which does not significantly differ from that of an absorbent impregnated with the sample matrix free of the element sought. Experimental parameters concerning the technique are presented. The excellent agreement of the zinc and bromine data with analytical results obtained by more conventional methods suggests that the technique can be used for the determination of other trace constituents in geologic materials. Application of the slope-ratio technique to other modes of instrumental analysis appears feasible.

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A method for determining the CEC and chemical composition of clays via XRF

Clay Minerals ◽

10.1180/0009855064130214 ◽

2006 ◽

Vol 41 (3) ◽

pp. 717-725 ◽

Cited By ~ 3

Author(s):

S. Battaglia ◽

L. Leoni ◽

F. Sartori

Keyword(s):

Matrix Effects ◽

Fluorescence Analysis ◽

Correction Method ◽

Exchange Capacity ◽

New Method ◽

Chemical Compositions ◽

Wet Chemistry ◽

X Ray ◽

Accuracy And Precision ◽

Source Clays

AbstractA new method for determining the cation exchange capacity (CEC) of clays is proposed. The method is based on X-ray fluorescence analysis of natural and Ba-exchanged clays following the analytical procedure suggested by Franzini et al. (1975). This procedure, which utilizes powder pellets and is based on a full matrix correction method, is frequently applied in Earth Sciences laboratories for the routine analysis of minerals and rocks. For the analysis of Ba-exchanged clays, Franzini's procedure has been modified slightly to account for the contribution of Ba to matrix effects.The new method, which furnishes both the CEC and the chemical compositions of the whole natural clay samples, has been tested on the eight ‘Source Clays’ of The Clay Minerals Society. The results compare well with data reported in the literature and confirm the accuracy and precision of the method and make it a valid alternative to techniques based on wet chemistry, execution of which is usually more time-consuming and which often requires greater analytical skill.

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A Non-Dispersive X-ray Fluorescence Unit for the Analysis of Biological Tissue Sections

Advances in X-ray Analysis ◽

10.1154/s0376030800000239 ◽

1957 ◽

Vol 1 ◽

pp. 297-313

Author(s):

Theodore Hall

Keyword(s):

Proportional Counter ◽

Biological Tissue ◽

Matrix Effects ◽

Pulse Height ◽

Fluorescence Analysis ◽

Mineral Elements ◽

X Ray ◽

Tissue Sections ◽

Characteristic Lines ◽

Secondary Radiator

AbstractAn X-ray fluorescence analysis unit has been designed and built especially for the measurement of certain mineral elements in individual biological tissue sections. Such a section may contain in the neighborhood of 10-10 grams of an element of interest, in a concentration in the range of 1-100 p.p.m.The unit consists of a special high-power X-ray tube with a builtin interchangeable secondary radiator, which irradiates the speciman with the characteristic lines of the radiator element) and a proportional counter and pulse-height analyzer system, which provides analysis of the X-ray spectrum emitted by the specimen. Because the emitted spectrum is greatly simplified by the use of an appropriate radiator element, a diffracting crystal can be omitted, permitting a great increase in absolute sensitivity.The system is feasible only because of two peculiarities of our biological specimens: they are so thin that matrix effects are negligible, and they consist essentially of a few mineral elements in a light matrix.Design considerations, calibration procedures, procedures for the analysis of the observed proportional counter pulse-height spectra and results to date will be discussed.

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