title: Matrix effect in guava multiresidue analysis by QuEChERS method and gas chromatography coupled to quadrupole mass spectrometry.
abstract: "Quick, Easy, Cheap, Effective, Rugged and Safe" (QuEChERS)-GC/MS analytical technique was used to evaluated matrix effect of twenty-two pesticides in guava. Validation parameters (selectivity, linearity, LOD, LOQ, accuracy and precision) were determined for multiresidue analysis. Statistical test (t-student) was applied to the coefficients of the curves obtained for the guava matrix. The matrix effect (ME) for each pesticide was evaluated through the study of slope ratios obtained of solvent and guava matrix curves. Most of the compounds had positive ME. The rates of recovery were satisfactory (73.97-119.38%), with a coefficient of variation (CV) less than 20%. Analysis of commercial guava samples showed the presence of 5 types of pesticides residues at levels ranging from 0.1 to 0.5 mg·kg(-1). The results reveal the presence of unauthorized pesticides for cultivation of guava. This data can assist government agencies to ensure food security.
authors.affiliation: Department of Analytical Chemistry and Physical Chemistry, Federal University of Ceará, R. Humberto Monte S/N, Pici, CEP: 60455-700, Fortaleza, Ceará, Brazil.
authors.forename: Jhonyson Arruda Carvalho
authors.initials: JA
authors.lastname: Guedes
authors.affiliation: Department of Analytical Chemistry and Physical Chemistry, Federal University of Ceará, R. Humberto Monte S/N, Pici, CEP: 60455-700, Fortaleza, Ceará, Brazil.
authors.forename: Renata de Oliveira
authors.initials: Rde O
authors.lastname: Silva
authors.affiliation: Industrial Technology Center of Ceará Foundation (Fundação Núcleo de Tecnologia Industrial do Ceará - NUTEC), Rua Rômulo Proença S/N, Campus do Pici, CEP: 60451-970, Fortaleza, CE, Brazil.
authors.forename: Cleidiane Gomes
authors.initials: CG
authors.lastname: Lima
authors.affiliation: Federal Institute of Education Science and Technology of Ceará (Instituto Federal de Educação Ciência e Tecnologia do Ceará - IFCE), Rodovia Iguatu/Várzea Alegre, Km 05 - Vila Cajazeiras, CEP: 63500-00, Iguatu, CE, Brazil.
authors.forename: Maria Aparecida Liberato
authors.initials: MA
authors.lastname: Milhome
authors.affiliation: Department of Analytical Chemistry and Physical Chemistry, Federal University of Ceará, R. Humberto Monte S/N, Pici, CEP: 60455-700, Fortaleza, Ceará, Brazil. Electronic address: ronaldo@ufc.br.
authors.forename: Ronaldo Ferreira
authors.initials: RF
authors.lastname: do Nascimento
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D010575:Pesticides / Q000032:analysis; D031647:Psidium / Q000737:chemistry*; D012997:Solvents
chemical_list: D010575:Pesticides; D012997:Solvents
keywords: Guava; Matrix effect; Multiresidue; Statistical test