Simultaneous liquid chromatography/mass spectrometry determination of both polar and “multiresidue” pesticides in food using parallel hydrophilic interaction/reversed-phase liquid chromatography and a hybrid sample preparation approach

•A novel approach for pesticide testing including both polar and nonpolar species.•Use of a parallel column assembly for simultaneous HILIC and RP separations.•Successfully tested for +45 compounds with HILIC/RPLC and HILIC/anion exchange LC.•Ability to analyse a broad range of species with log Kow over 10 orders.•Novel sample preparation proposed based on the fusion of QuEChERS and QuPPe.

Pesticide testing of foodstuffs is usually accomplished with generic wide-scope multi-residue methods based on liquid chromatography tandem mass spectrometry (LC-MS/MS). However, this approach does not cover some special pesticides, the so called “single-residue method” compounds, that are hardly compatible with standard reversed-phase (RP) separations due to their specific properties. In this article, we propose a comprehensive strategy for the integration of single residue method compounds and standard multiresidue pesticides within a single run. It is based on the use of a parallel LC column assembly with two different LC gradients performing orthogonal hydrophilic interaction chromatography (HILIC) and reversed-phase (RPLC) chromatography within one analytical run. Two sample aliquots were simultaneously injected on each column, using different gradients, being the eluents merged post-column prior to mass spectrometry detection. The approach was tested with 41 multiclass pesticides covering a wide range of physicochemical properties across several orders of log Kow (from −4 to +5.5). With this assembly, distinct separation from the void was attained for all the pesticides studied, keeping similar performance in terms of sensitivity, peak area reproducibility (<6 RSD% in most cases) and retention time stability of standard single column approaches (better than ± 0.1 min). The application of the proposed approach using parallel HILIC/RPLC and RPLC/aqueous normal phase (Obelisc) were assessed in leek using LC-MS/MS. For this purpose, a hybrid QuEChERS (Quick, easy, cheap, effective, rugged and safe)/QuPPe (quick method for polar pesticides) method was evaluated based on solvent extraction with MeOH and acetonitrile followed by dispersive solid-phase extraction, delivering appropriate recoveries for most of the pesticides included in the study within the log Kow in the range from −4 to +5.5. The proposed strategy may be extended to other fields such as sport drug testing or environmental analysis, where the same type of variety of analytes featuring poor retention within a single chromatographic separation occurs.