Development and validation of qualitative screening, quantitative determination and post-targeted pesticide analysis...

The following qualitative screening and quantitative determination of 201 pesticides present a detailed optimization making use of design of experiments (DoE). The post-targeted screening took advantage of an upgradeable database to extend the survey further to perform a standard-free novel quantitation by liquid chromatography high resolution mass spectrometry (LC-HRMS). The fine tuning of instrumental parameters allowed the best method selectivity, sensitivity and reproducibility for the compounds under study. Among the factors considered, the heated electrospray source (HESI), the sample composition and the MS/MS acquisition modes were assessed, including the all-ion fragmentation (AIF) mode and different versions of the variable data independent acquisition (vDIA). The results of the optimization showed that selected HESI conditions, a methanol/water (1:1) sample composition and a vDIA acquisition method increased the signal for most compounds with a remarkable benefit on signal shape and intensity. The method showed adequate analytical performance when assessed in local produce.