Resumo

TORRES-RODRIGUEZ, Duilio; MARCO, Lué Merú; GOMEZ, Carlos  e  GARCIA-ORELLANA, Yelitza. Total X-Ray Fluorescence (TXRF) as an alternative method for the determination of micronutrients in soils of the Quíbor depression (Venezuela). TecnoL. [online]. 2022, vol.25, n.53, e203.  Epub 08-Ago-2022. ISSN 0123-7799.  https://doi.org/10.22430/22565337.2195.

In soil fertility evaluation, new alternative analytical methods should be proposed to determine microelements in a fast and inexpensive way, but with results similar to those obtained with standardized analytical procedures. Therefore, the objective of this study was to compare the results of the determination of four microelements (Cu, Mn, Fe, and Zn) by two methods: (1) Total X-Ray Fluorescence (TXRF) and (2) atomic absorption. For this purpose, Cu, Mn, Zn, and Fe contents were quantified in two aridisols: one located in a natural forest with high organic matter content (PS1) and another one with low organic matter content (PS2) as a result of intensive agricultural activity. The samples were taken at a depth of ten centimeters. The quantification of microelements was carried out by TXRF (alternative method proposed here) and atomic absorption (standard method). In both cases, microelements were previously extracted with ammonium acetate. At each location, three samples were taken with ten replicates, which totals thirty experimental units. The data were analyzed using Student’s t-test with a p-value < 0.05. The results showed that, in both soils, TXRF presented values similar to those obtained by atomic absorption regarding Mn and Zn, but it overestimated the values of Cu and Fe. Hence, TXRF can be safely employed to determine Mn and Zn, but not Cu or Fe. This method is attractive due to its speed and lower use of reagents, decreasing the risks of contamination and obtaining reliable results for the determination of microelements for soil fertility or contamination risk analysis.

Palavras-chave : Chemical analysis; soil contamination; environmental impact; microelements.

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