Speaker
Description
The monitoring of pesticide residues in cereal-based products is important to ensure food safety and compliance with maximum residue levels (MRLs) enforced by the current legislation [1]. In this study a rapid GC-MS/MS method was validated for simultaneous analysis of 95 pesticides in cereal-based products. The samples, fortified with triphenyl phosphate (Sigma-Aldrich, Saint Louis, USA) as an internal standard, were initially extracted with acetonitrile using a vortex, combined with a salting out procedure by the QuEChERS extraction kit (5982-7650, Agilent, USA). Prior GC-MS/MS analysis (Agilent 8890 GC/7000D TQ, Agilent, USA), a dispersive SPE cleanup was applied to the samples and obtained supernatants (5 min, 5000 rpm) were filtered through a PTFE filter (0.2 µm).
Analysis of spiked samples, prepared by adding standard pesticide solution mixture (AccuStandard, Inc., USA) to one representative sample consisting of pesticide-free grains (rice, maize, barley, oat and rye), was conducted at three different levels (2.5, 5 and 10
μg kg-1). Mean recoveries from six replicates ranged from 70.78 to 115.05%, with relative standard deviation lower than 20. The limit of quantification (LOQ) for all pesticides was 5 μg kg-1 which is below the national MRLs for grains from which the cereal product was derived [2]. The correlation coefficient (R2) was ≥ 0.990 for all pesticides. Evaluation was performed using a matrix-matched calibration curve for each pesticide in a concentration range of 2.5 to 50 ng mL-1. The ability of the method to identify pesticides even when other components are present in the samples was demonstrated by the determination of pesticides at concentrations below the LOQ. Considering that conventionally cultivated grains contain some pesticides as a result of their broad use in agricultural practices to produce high yields [3], this method with a 21-min run time may have a practical application for safety control of residues in cereal-based food. Such method that could quantify residues at lower levels than legal limits is needed to ensure a high degree of consumer protection, since a specific pesticide/product combination may exceed health-based recommendation levels and pose a risk to health.
References:
[1] V. Nardelli, V. D’Amico, M. Ingegno, I. Della Rovere, M. Iammarino, F. Casamassima, A. Calitri, D. Nardiello, D. Li, M. Quinto. Appl. Sci. 11, 2021,7283.
[2] Rulebook on general and special requirements for food and feed safety respecting maximum residue levels of pesticides. Official Gazette of Republic of Macedonia № 91, 2018.
[3] S. Walorczyk, D. Drożdżyński, J. Kowalska, D. Remlein-Starosta, A. Ziółkowski, M. Przewoźniak, B. Gnusowski. Food Chem.,15, 2013, 482-487.
Keywords: cereal-based products, pesticide residues, GC-MS/MS.
