Simultaneous determination of phosphite and phosphate in fertilizers by Raman spectroscopy.

Autor: Oliveira EM; Institute of Chemistry, São Paulo State University (UNESP), Araraquara City 14800-060, São Paulo State, Brazil., Rogero M; Institute of Chemistry, São Paulo State University (UNESP), Araraquara City 14800-060, São Paulo State, Brazil., Ferreira EC; Institute of Chemistry, São Paulo State University (UNESP), Araraquara City 14800-060, São Paulo State, Brazil., Gomes Neto JA; Institute of Chemistry, São Paulo State University (UNESP), Araraquara City 14800-060, São Paulo State, Brazil. Electronic address: jose.anchieta@unesp.br.
Jazyk: angličtina
Zdroj: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy [Spectrochim Acta A Mol Biomol Spectrosc] 2021 Feb 05; Vol. 246, pp. 119025. Date of Electronic Publication: 2020 Oct 03.
DOI: 10.1016/j.saa.2020.119025
Abstrakt: Raman spectroscopy is emerging and powerful technique for identifying oxyanions of phosphorus, but it still is not straightforward applied to identify and quantify simultaneously phosphite and phosphate species in solution. Herein, simultaneous determination of phosphate (PO 4 ) and phosphite (PO 3 ) in fertilizer were evaluated by Raman spectroscopy. The influence of pH on Raman spectra of species was evaluated at various solution pH values, and the results showed accurate and selective analysis for phosphate and phosphite by using pH = 10.0 and bands located at 874 cm -1 and 2321 cm -1 , respectively. Linear working range in the 0.15%-6.20% (w/v) P concentration was consistently obtained with regression coefficients (r) of 0.9953 (PO 4 ) and 0.9945 (PO 3 ). The limits of detection were 0.10% (w/v) P (PO 4 ) and 0.05% (w/v) P (PO 3 ). Relative standard deviations were lower than 6% for samples containing 10% P 2 O 5 (PO 4 ) and 31% P 2 O 5 (PO 3 ). Commercial fertilizers were analyzed by the proposed method using external calibration and found concentrations of P were in agreement with those obtained by the comparative spectrophotometric method at the 95% confidence level (paired t-test). Recoveries of spiked samples were in the 92-110% range.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2020 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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