Novel Method Development for Extraction and Analysis of Pesticide Residues in Human Serum Samples

In recent years, exposure to pesticides has gained widespread attention due to their adverse health effects. Long-term exposure to pesticides has shown hazardous effects on vital functions of the human nervous and reproductive systems. Therefore, it is crucial to determine the extent of pesticide exposure in humans. Primarily, it is quite challenging to determine trace levels of pesticide residues in biological matrices. Hence, a quick, multi-residue extraction procedure was experimented for pesticide residue analysis in human serum. Herein, the original QuEChERS extraction method was modified for achieving the best possible recoveries. A total of 15 representative pesticides from each class were selected and fortified into the human serum samples. The extraction was performed by employing acidified solution containing acetonitrile and ethyl acetate followed by vortex and centrifugation. The obtained aqueous layer was collected and vapourised to dryness and d-SPE clean-up was conducted utilising PSA. The extracted sample was injected into the GC-MS/MS system under MRM mode. The method development parameters such as linearity, % RSD, accuracy, LOD, LOQ and % ME were assessed. The results obtained for the serum matrix were found to be within the criteria mentioned in European Union SANTE/12682/2019 guidelines for method validation. The developed solitary method is quick, simple and highly efficient for routine pesticide residue analysis. Hence, a wide spectrum of pesticides can be analysed utilising the proposed method for human serum.

Liquid chromatography versus supercritical fluid chromatography coupled to mass spectrometry: a comparative study of performance for multiresidue analysis of pesticides

Abundant studies have been published evaluating different parameters of reverse-phase liquid chromatography (LC) and supercritical fluid chromatography (SFC), both coupled to electrospray (ESI)/mass spectrometry (MS) for pesticide residue analysis. However, there is a lack of a comprehensive comparative study that facilitates deep knowledge about the benefits of using each technique. In the present study, the same mass spectrometer was used coupled to both liquid and supercritical fluid chromatographies with a multiresidue method of 215 compounds, for the analysis of pesticide residues in food samples. Through the injection of the spiked extracts, separate experiments were conducted. A study of the optimum ion source temperature using the different chromatography modes was performed. The results were evaluated in terms of sensitivity with tomato, leek, onion, and orange as representative fruit and vegetable matrices. The compounds which reported the highest area values in each chromatography were evaluated through their substance groups and polarity values. The impact of matrix effects obtained in tomato matrix was similar for both cases; however, SFC clearly showed better results in analyzing matrices with a higher number of natural co-extracted compounds. This can be explained by the combination of two effects: (i) chromatography separation and (ii) ion source efficiency. The chromatographic elution presented different profiles of matrix components, which had diverse impact on the coelution with the analytes, being more beneficial when SFC was used in the matrices studied. The data showed that the best results obtained in SFC are also related to a higher ionization efficiency even when the ESI emitter tip was not optimized for SFC flow. In the present study a comprehensive evaluation of the benefits and drawbacks of these chromatography modes for routine pesticide residue analysis related to target compounds/commodities is provided. Graphical abstract