Ismael A. Aguayo-Villarreal

Direct immersion single drop micro-extraction method for multi-class pesticides analysis in mango using GC–MS

Due the negative effects of pesticides on environment and human health, more efficient and environmentally friendly methods are needed. In this sense, a simple, fast, free from memory effects and economical direct-immersion single drop micro-extraction (SDME) method and GC-MS for multi-class pesticides determination in mango samples was developed. Sample pre-treatment using ultrasound-assisted solvent extraction and factors affecting the SDME procedure (extractant solvent, drop volume, stirring rate, ionic strength, time, pH and temperature) were optimized using factorial experimental design. This method presented high sensitive (LOD: 0.14-169.20μgkg-1), acceptable precision (RSD: 0.7-19.1%), satisfactory recovery (69-119%) and high enrichment factors (20-722). Several obtained LOQs are below the MRLs established by the European Commission; therefore, the method could be applied for pesticides determination in routing analysis and custom laboratories. Moreover, this method has shown to be suitable for determination of some of the studied pesticides in lime, melon, papaya, banana, tomato, and lettuce.

Analytical Method for Pesticides in Avocado and Papaya by Means of Ultra-High Performance Liquid Chromatography Coupled to a Triple Quadrupole Mass Detector: Validation and Uncertainty Assessment: Pesticides analysis by UHPLC-MS/MS …

In this work, the uncertainty estimation for the determination of ametryn, carbofuran, atrazine, carbaryl, and methyl parathion in papaya and avocado is presented, along with other validation parameters. The analytical method was developed using Quick, Easy, Cheap, Effective, Rugged, and Safe extraction and ultrahigh performance liquid chromatography coupled to a triple quadrupole mass detector. The method validation showed that the linear correlation coefficients were higher than 0.99 for both fruits. The limits of detection for avocado and papaya were in the range of 0.022 to 0.46 and 0.003 to 0.109 μg/g, respectively. Intermediate precision varied from 5.3% to 13.0% in papaya, and from 4.8% to 20.2% in avocado. Recoveries obtained for each pesticide in both matrices ranged between 61.3% and 119.0%. Matrix effect was calculated for all compounds in both fruits. Finally, the overall uncertainty was lower than 36% for both fruits. PRACTICAL APPLICATION The present analytical method could be used for pesticides determination in different kind of fruits as papaya and avocado and as a practical guide for uncertainty and matrix effect determination.