title: Evaluation of alternative sorbents for dispersive solid-phase extraction clean-up in the QuEChERS method for the determination of pesticide residues in rice by liquid chromatography with tandem mass spectrometry.
abstract: Many compounds are used for pest control during the production and storage of rice, making it necessary to employ multiclass methods for pesticide residues determination. For this purpose, QuEChERS-based methods are very efficient, fast and accurate, and improvements in the clean-up step are important, especially for complex matrices, like cereals. In this work, different sorbents such as chitosan, florisil(®) , alumina, diatomaceous earth, graphitized carbon black, besides the commonly used primary secondary amine and octadecylsilane, were evaluated for dispersive solid-phase extraction clean-up in acetate-buffered QuEChERS method for the determination of residues of 20 representative pesticides and one metabolite in rice by liquid chromatography coupled to tandem mass spectrometry. The sorbent C18 presented the best results, however, chitosan showed similar results, and the best performance among the unconventional sorbents evaluated. The method limit of quantification, attending accuracy (70-120% recovery) and precision (RSD ≤20%) criteria, ranged from 5 to 20 μg/kg. Results showed that chitosan is an effective alternative to reduce analysis costs, maintaining the method reliability and accuracy.
authors.affiliation: Departamento de Química, Universidade Federal de Santa Maria, Santa Maria-RS, Brazil.|Universidade Federal da Fronteira Sul - Campus Realeza, Realeza-PR, Brazil.
authors.forename: Liziara da C
authors.initials: Lda C
authors.lastname: Cabrera
authors.affiliation: Escola de Química e Alimentos, Universidade Federal do Rio Grande, Rio Grande-RS, Brazil.
authors.forename: Sergiane S
authors.initials: SS
authors.lastname: Caldas
authors.affiliation: Departamento de Química, Universidade Federal de Santa Maria, Santa Maria-RS, Brazil.
authors.forename: Osmar D
authors.initials: OD
authors.lastname: Prestes
authors.affiliation: Escola de Química e Alimentos, Universidade Federal do Rio Grande, Rio Grande-RS, Brazil.
authors.forename: Ednei G
authors.initials: EG
authors.lastname: Primel
authors.affiliation: Departamento de Química, Universidade Federal de Santa Maria, Santa Maria-RS, Brazil.
authors.forename: Renato
authors.initials: R
authors.lastname: Zanella
mesh_terms: D000327:Adsorption; D002853:Chromatography, Liquid; D012275:Oryza / Q000737:chemistry* / Q000378:metabolism; D010573:Pesticide Residues / Q000032:analysis* / Q000378:metabolism; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry
chemical_list: D010573:Pesticide Residues
keywords: Clean-up; Pesticides; Rice; Sorbents