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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Direct analysis of plant leaves by EDXRF and LIBS: microsampling strategies and cross-validation

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Bueno Guerra, Marcelo Braga [1] ; Adame, Andressa [1] ; de Almeida, Eduardo [1] ; Arantes de Carvalho, Gabriel Gustinelli [1] ; Stolf Brasil, Marcos Augusto [1] ; Santos, Jr., Dario [2] ; Krug, Francisco Jose [1]
Número total de Autores: 7
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Technol & Innovat Sustainable Agr, Res Support Ctr, Ctr Energia Nucl Agr, BR-13416000 Piracicaba, SP - Brazil
[2] Univ Fed Sao Carlos, Dept Ciencias Exatas & Terra, BR-09972270 Diadema, SP - Brazil
Número total de Afiliações: 2
Tipo de documento: Artigo Científico
Fonte: Journal of Analytical Atomic Spectrometry; v. 30, n. 7, p. 1646-1654, 2015.
Citações Web of Science: 9

Microsampling strategies were evaluated for the direct analysis of dried sugar cane leaves by energy-dispersive X-ray fluorescence spectrometry (EDXRF) and laser-induced breakdown spectroscopy (LIBS). The analysis by EDXRF was carried out by irradiating each leaf fragment in its middle portion with a collimated 5 mm X-ray spot size for 50 s, allowing the determination of P, K, Ca, S, Fe, Mn and Si. EDXRF was also useful to conclude that 15 leaf fragments (37.5% of the recommended sampling area) were enough for attaining a representative analytical response from the whole diagnostic leaf. Regarding LIBS, which employs a substantial smaller ablation area (i.e., 750 mu m laser spot size), sampling strategies were defined by taking into account the microchemical distribution of P, Ca, Mg, Fe, Mn, B and Si in a 9 mm x 9 mm leaf fragment area. The proposed sampling protocol relied on the interrogation (rastering) of 3 equally spaced sampling lines in each leaf fragment with 48 accumulated laser pulses per line (Nd:YAG at 1064 nm, 5 ns, 10 Hz, 50 J cm(-2)) perpendicular to the leaf midrib. This strategy enabled the simultaneous determination of P, K, Ca, Mg, Fe, Cu, Mn, Zn, B and Si by LIBS. Cross-validation between LIBS and EDXRF for P, K, Ca, Fe, Mn and Si predicted mass fractions presented high linear correlation coefficients of up to 0.9778 (selecting 15 leaf fragments per diagnostic leaf from 10 different sugar cane varieties). The results provide insights into a novel and promising strategy for direct and fast plant nutrition diagnosis, fostering further studies for in situ analysis of fresh leaves, strengthening the implementation of Precision Agriculture and Green Chemistry concepts. (AU)

Processo FAPESP: 10/16379-0 - Estratégias de microamostragem para a análise de tecidos biológicos por espectrometria de emissão óptica com plasma induzido por laser
Beneficiário:Gabriel Gustinelli Arantes de Carvalho
Modalidade de apoio: Bolsas no Brasil - Doutorado
Processo FAPESP: 12/16203-5 - Estratégias para análise direta de folhas de cana-de-açúcar por espectrometria de emissão óptica com plasma induzido por laser (LIBS)
Beneficiário:Marcelo Braga Bueno Guerra
Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado