A comprehensive analysis of 201 pesticides for different herbal species-ready application using gas chromatography-tandem mass spectrometry coupled with QuEChERs.

Developing an analysis of multi-pesticide residues for different herbal species-ready applications is a challenge. In the present work, a comprehensive analysis was proposed for rapid detection of 201 pesticides in various medicinal herbs. Samples were extracted and cleaned up with a high throughput pretreatment approach (modified QuEChERS), and then detected by gas chromatograph coupled to an electron impact ionization triple quadrupole mass spectrometer (GC-EI-MS/MS). The clean-up procedure has been optimized using four types of representative medicinal herbs with different primary or secondary metabolites. Moreover, a mixture of analyte protectants (APs) was to improve the peak shape and intensity of some compounds. The performance of the method was validated according to the European Union SANTE/11813/2017 regulatory guidelines. The limit of quantification (LOQ) was determined to be ≤10 ng mL-1, and the recovery was between 70.0%-120.0%, with ≤20% RSD for the majority of pesticides. Sixty samples belonging to different species of medicinal herbs (such radix, flos, cortex, fructus, and seeds) were analyzed to evaluate the applicability of the optimized method. High frequency of chlorpyrifos was found in Citri reticulatae pericarpium, Crataegi fructus and Cuscutae semen samples.