Banca de DEFESA: DANIEL RIBEIRO DE LIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : DANIEL RIBEIRO DE LIRA
DATE: 28/02/2025
TIME: 14:00
LOCAL: Auditório do PPG em Ciência do Solo
TITLE:

Comparison between portable X-ray fluorescence and ICP-OES in the determination of metals in soils

KEY WORDS:

pXRF, soil contamination, soil pollution, trace elements

PAGES: 33
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Química do Solo
SUMMARY:

The determination of heavy metals in soil is essential for studies in environments suspected of contamination. Spectrometry, using equipment based on atomic absorption (AA), optical emission (ICP-OES), or mass spectrometry (ICP-MS), is the most widely used technique for this purpose. However, sample digestion with concentrated acids is required for metal determination, generating environmentally harmful residues. This study aimed to evaluate the performance of a portable X-ray fluorescence spectrometer (FRXp) in determining Ba, Cr, Cu, Fe, Pb, Mn, Ti, V, and Zn in soils, compared to an ICP-OES. A total of 142 soil samples from the metropolitan region of Recife were analyzed, which were crushed, sieved (200 mesh), and had their metal concentrations determined using both instruments. The results indicated that the FRXp showed a high correlation for Ba, Cu, and Mn. However, V, Zn, and Cr exhibited low determination coefficients and weak correlations in validation, demonstrating that the FRXp was not effective for their quantification. The greatest discrepancy was observed for Ni, with values underestimated by the FRXp. The differences between methods can be attributed to spectral interferences, matrix effects, and the detection limits of the FRXp. It is concluded that, although the FRXp has potential for environmental analyses, its accuracy depends on rigorous calibration and individualized approaches for each metal and soil type.

COMMITTEE MEMBERS:
Presidente - CLISTENES WILLIAMS ARAUJO DO NASCIMENTO
Externo à Instituição - ALFREDO ALVAREZ MONTERO
Externa à Instituição - PAULA RENATA MUNIZ ARAUJO - UFRPE