Determination of pesticide residues in tomato using dispersive solid-phase extraction and gas chromatography/ion trap mass spectrometry

Abstract

A cultura do tomate é frequentemente afetada por pragas, doenças e estresses abióticos, resultando em menor produtividade e perda de qualidade dos frutos. O uso intensivo de pesticidas em tomates sem utilização das boas práticas agrícolas tem causado grande preocupação quanto à provável contaminação do produto final. O método QuEChERS foi utilizado para a determinação de seis pesticidas (buprofezina, carbofurano, α-endosulfan, β-endosulfan, sulfato de endosulfan e monocrotofós) em amostras de tomate coletadas em supermercados. O método envolveu a extração líquido-líquido com acetonitrila, adição de MgSO4 e NaCl seguida de extração em fase sólida dispersiva com PSA (amina primária secundária) e as análises foram realizadas com cromatografia gasosa/espectrometria de massa ion trap. O estudo de recuperação para os pesticidas variou de 71 a 111% e o desvio padrão relativo foi inferior a 15%. Não foram detectados resíduos de pesticidas (> LOD) nas trinta e três amostras de tomate analisadas.Tomato crop is frequently damaged by diseases, pests and abiotic stresses, resulting in lower yielding and loss of fruit quality. The intensive use of pesticides in tomatoes without observation of good agriculture practices and regulations has caused great concern with a probable final product contamination. The QuEChERS method of sample preparation was used for the determination of six pesticides (buprofezin, carbofuran, endosulfan-α, endosulfan-β, endosulfan sulfate and monocrotophos) in thirty three tomato samples collected from local market retailers. The method involved extraction with acetonitrile, liquid-liquid partition with addition of MgSO 4 and NaCl followed by dispersive solid phase extraction using primary secondary amine sorbent and the analyses were carried out with a gas chromatography/mass spectrometry equipment by ion trap. Recovery studies for different pesticides ranged from 71 to 111% and the relative standard deviation (RSD) was below 15%. No pesticide residue was detected (> LOD) among the thirty three tomato samples analysed.Keywords: QuEChERS, gas chromatography, pesticides, tomato IntroductionTomato (Lycopersicon esculentum Mill) fruit is worldwide one of the most important vegetable components of the human diet and it is consumed in natura, cooked or processed. Besides the basic nutritional properties, tomatoes contain bioactive compounds with antioxidant properties such as ascorbic acid, vitamin E, carotenoids (lycopene), flavonoids and phenolic acids that benefit human health. Nevertheless, tomato plants are susceptible to several pests and diseases that have been controlled with pesticides in different plant stadium in order to avoid significant yield losses. 1,2 According to recent FAO information, the ten greatest tomato producer countries in 2007 were: China, United States, Turkey, India, Egypt, Italy, Iran, Spain, Brazil and Mexico. These countries are responsible for more than 73% of the world's tomato production, 3 which doubled during the last 20 years.The crop expansion is mainly attributed to...

Liquid chromatography–electrospray ionization tandem mass spectrometry and dynamic multiple reaction monitoring method for determining multiple pesticide residues in tomato

“…However, these techniques require considerable investment in instrumentation (automated), training of staff, and have some limitations in the scope of pesticides analyzed. In 2003, Anastassiades, Lehotay, Stajnbaher, and Schenck (2003) introduced a procedure for sample preparation called QuEChERS, which has been widely used for the detection of pesticides and other compounds in a variety of matrices (Andrade, Freguglia, Furlani, Torres, & Tornisielo, 2011;Camino-Sanchez et al, 2010;GilbertLopez, Garcia-Reyes, Lozano, Fernandez-Alba, & Molina-Diaz, 2010).…”

Analysis of tomato matrix effect in pesticide residue quantification through QuEChERS and single quadrupole GC/MS

“…Determination of matrix effect. Different test for the determination of matrix effect and matrix effect extent had been reported in the literature (Hajšlová et al, 1998;Guerrero, 2003;Kruve et al, 2009;Ferrer et al, 2011;Moura et al, 2011;Ahumada and Zamudio, 2011;de Sousa et al, 2012;Kwon et al, 2012), some of them were tested in this scope, besides the ANOVA procedure.…”

“…Some authors use statistical comparison, the matrix effect is determine, through Fisher's (variance) and Student's test (means), between the slope of the pesticide calibration curve in the solvent solutions and the slope of the pesticide calibration curve in matrix extract solutions. Both curves could be prepared with or without internal standard (Guerrero, 2003;Ferrer et al, 2011;Moura et al, 2011). Also, it is had been reported for this purpose other statistical procedures like ANCOVA (Ahumada and Zamudio, 2011); or Principal Components Analysis (PCA) (de Sousa et al, 2012).…”

Evaluation and prevention of the negative matrix effect of terpenoids on pesticides in apples quantification by gas chromatography–tandem mass spectrometry

“…cereal grains [12), liquids and beverages, such as fruitjuice, olive oil, honey [ 13 ) ... , and processed products, such as potato chips, and crackers [14][15][16][17]. Alternative methods have been developed, based on the addition of internai labeled standards [18), calibration in the matrix [19,20), the addi tion of analyte protectants (e.g. sorbitol, -y-lactone-gulonic acid) [20), or calibration correction factors [8).…”

“…Alternative methods have been developed, based on the addition of internai labeled standards [18), calibration in the matrix [19,20), the addi tion of analyte protectants (e.g. sorbitol, -y-lactone-gulonic acid) [20), or calibration correction factors [8). Calibration correction factors are added to both the standards and the sampi es.…”