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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

UV-Vis spectrophotometry coupled to chemometric analysis for the performance evaluation of atrazine photolysis and photocatalysis

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Author(s):
Moreira, Ailton Jose [1, 2] ; Lemos, Sherlan [3] ; Coelho, Dyovani [1] ; Mascaro, Lucia [1] ; Freschi, Gian [2] ; Pereira, Ernesto [1]
Total Authors: 6
Affiliation:
[1] Univ Fed Sao Carlos, Chem Dept, Sao Carlos, SP - Brazil
[2] Univ Fed Alfenas, Campus Pocos Caldas, Pocos De Caldas, MG - Brazil
[3] Univ Fed Paraiba, Dept Chem, Joao Pessoa, Paraiba - Brazil
Total Affiliations: 3
Document type: Journal article
Source: Environmental Science and Pollution Research; NOV 2021.
Web of Science Citations: 0
Abstract

In this study, a spectrophotometric-chemometric (Spec-Chem) approach was applied as an alternative to chromatography to monitor ATZ and by-products after photolytic and photocatalytic oxidation aiming to unveil the ATZ degradation mechanism. Spec-Chem is an accessible, easy-to-operate, low-cost analytical approach to monitor atrazine (ATZ) and by-products, and its applicability was validated by HPLC, the reference technique for the evaluation of pollutant degradation mechanisms. The chromatographic (DChro) and spectrophotometric (DSpec) data found 95% and 57% ATZ removal after 30 min, respectively, proving that the DSpec erroneously induces a 38% loss in removal efficiency. When DSpec was treated by multivariate curve resolution (MCR) analysis for providing chemometric data (DChem), it found ATZ removal and hydroxyatrazine (HAT) formation statistically equal to DChro (t-test, p = 0.05). After unraveling the ATZ degradation mechanism using Spec-Chem, a new hypothesis for the kinetic calculation of ATZ degradation was presented, where the concentrations of ATZ and HAT were used to find k and R-2 values representative for the ATZ degradation mechanism. The values found for k were compatible with the literature under similar conditions of ATZ degradation, and the linear correlation coefficients (R-2 =0.99) showed an optimal fit for the proposed hypothesis. Thus, Spec-Chem was successfully applied to unravel the mechanism of photocatalytic degradation of ATZ in the presence of TiO2, while k was obtained by the new hypothesis proposed that considered ATZ and HAT concentration as parameters of kinetic interest. Therefore, the importance of monitoring quantitatively ATZ and HAT were provided in this study, providing new information for the scientific community. (AU)

FAPESP's process: 14/50249-8 - Green chemistry: sustainable synthetic methods employing benign solvents, safer reagents, and bio-renewable feedstock
Grantee:Arlene Gonçalves Corrêa
Support Opportunities: Research Grants - Research Centers in Engineering Program
FAPESP's process: 17/11986-5 - Generation and storage of New Energy: bringing technological development for the country
Grantee:Ana Flávia Nogueira
Support Opportunities: Research Grants - Research Centers in Engineering Program
FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
Grantee:Elson Longo da Silva
Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC