Unified Method for Target and Non-Target Monitoring of Pesticide Residues in Fruits and Fruit Juices by Gas Chromatography-High Resolution Mass Spectrometry

A new polyvalent wide-scope analytical method, valid for both raw and processed (juices) fruits, combining target and non-target strategies, has been developed and validated to determine low concentrations of 260 pesticides, as well as many potential non-target substances and metabolites. The target approach has been validated according to SANTE Guide requirements. Trueness, precision, linearity, and robustness values were validated in raw fruit (apple) and juice (apple juice) as representative solid and liquid food commodities. Recoveries were between 70-120% and two ranges of linearity were observed: 0.5-20 mu g kg(-1) (0.5-20 mu g L-1 apple juice) and 20-100 mu g kg(-1) (20-100 mu g L-1 apple juice). The limits of quantification (LOQs) reached were lower than 0.2 mu g kg(-1) in apple (0.2 mu g L-1 apple juice) in most cases. The developed method, based on QuEChERS extraction followed by gas chromatography-high resolution mass spectrometry (GC-HRMS), achieves part-per-trillions lower limits, which allowed the detection of 18 pesticides in commercial samples. The non-target approach is based on a retrospective analysis of suspect compounds, which has been optimized to detect up to 25 additional compounds, increasing the scope of the method. This made it possible to confirm the presence of two pesticide metabolites which were not considered in the target screening, phtamlimide and tetrahydrophthalimide.

Automated summary

A new polyvalent wide-scope analytical method has been developed and validated to detect low concentrations of 260 pesticides, non-target substances, and metabolites in both raw and processed fruits. The target approach was validated according to SANTE Guide requirements, showing satisfactory results in terms of accuracy, precision, linearity, and robustness. The method, based on QuEChERS extraction followed by GC-HRMS, achieved part-per-trillions lower limits, allowing the detection of 18 pesticides in commercial samples. An optimized non-target approach was also applied, leading to the identification of additional compounds, including pesticide metabolites not considered in the target screening.