Influence of compression on soil characterization by X ray fluorescence ; Influência da compressão em caracterização de solo por fluorescência de raios X

The study of soil mineralogy has been highlighted in recent years, as well as the search for alternative analytical techniques for soil analysis. The classical methods for determination of total oxides in soil expose the analyst to chemical hazards and require time-consuming sample preparation and decomposition. XRF is being employed for this type of analysis, since it does not requires the use of chemical solvents. However, the technique requires samples with a smooth and homogeneous surface. The objective of this study was to verify if the soil compression (in 5 t, 10 t and 15 t) influenced the determination of the oxides content in soils of different municipalities of the state of Rio Grande do Sul (Passo Fundo and Cruz Alta). The experiments and the analysis of the data showed that the XRF technique presented low coefficients of variation and low standard deviation and did not have statistical difference between the samples of the same type of soil. The lower variations of these analytical criteria were obtained for soil analysed in the form of powder. Therefore, the most suitable form for the analysis of these soils is in the sedimentary form, however, it is still recommended the use of statistical tools to verify the reliability of the data obtained. ; O estudo referente a mineralogia do solo tem sido destaque nos últimos anos, bem como a procura por técnicas analíticas alternativas para análises de solo. Os métodos atuais para as determinações dos teores totais de óxidos no solo expõem o analista à riscos químicos e demandam preparo e abertura demorados. A Fluorescência de Raios X (FRX) está sendo muito empregada para esse tipo de análise, pois não se faz necessária a abertura das amostras do solo com solventes químicos. No entanto, a técnica requer amostras com superfície lisa e homogênea. O objetivo foi verificar se a compressão do solo (em 5 t, 10 t e 15 t) influenciava na determinação dos teores de óxidos em solos de diferentes municípios do estado do Rio Grande do Sul (Passo Fundo e Cruz Alta). Os ...