Quantitative analysis by energy dispersive X-ray fluorescence by the transmission method applied to geological samples

Scientia Agricola

S.m. Simabuco²  V.f. Nascimento Filho¹ 

[1] ,UNICAMP FEC Hydraulics and Sanitation DepartmentCampinas SP ,Brasil

关键词: quantitative analysis;    X-ray fluorescence;    geological samples;    energy dispersive;    Análise quantitativa;    fluorescência de raios X;    amostras geológicas;    energia dispersiva;   

DOI  :  10.1590/S0103-90161994000200001

来源: SciELO

【 摘 要 】

Three certified samples of different matrices (Soil-5, SL-1/IAEA and SARM-4/SABS) were quantitatively analysed by energy dispersive X-ray fluorescence with radioisotopic excitation. The observed errors were about 10-20% for the majority of the elements and less than 10% for Fe and Zn in the Soil-5, Mn in SL-1, and Ti, Fe and Zn in SARM-4 samples. Annular radioactive sources of Fe-55 and Cd-109 were utilized for the excitation of elements while a Si(Li) semiconductor detector coupled to a multichannel emulation card inserted in a microcomputer was used for the detection of the characteristic X-rays. The fundamental parameters method was used for the determination of elemental sensitivities and the irradiator or transmission method for the correction of the absorption effect of characteristic X-rays of elements on the range of atomic number 22 to 42 (Ti to Mo) and excitation with Cd-109. For elements in the range of atomic number 13 to 23 (Al to V) the irradiator method cannot be applied since samples are not transparent for the incident and emergent X-rays. In order to perform the absorption correction for this range of atomic number excited with Fe-55 source, another method was developed based on the experimental value of the absorption coefficients, associated with absorption edges of the elements.

【 授权许可】

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