Impact of pesticide formulation excipients and employed analytical approach on relative matrix effects of pesticide determination in strawberries.

Relative matrix effects between an ambient mass spectrometric technique known as coated blade spray (CBS) and liquid chromatographic separation approach when applied to multiresidue pesticide analysis in strawberry samples are explored. Acceptable slope relative standard deviations (RSD <15 %) were observed for the 9 compounds under study for both CBS-MS/MS (2.2-12.6 %) and LC-MS/MS (2.8-12.9 %) approaches. The findings signify both the elimination of relative matrix effects with the sample preparation and matrix match calibration with internal standard correction methods employed along with no matrix effect compromise made when using the direct-to-MS approach. Similarly, slopes of pesticides spiked from commercially available formulations (containing one or two pesticides) were found to not differ significantly from slopes generated with multiresidue pesticide standards (containing 24 additional pesticides besides the target 9 analytes) with either technique, highlighting the resistance of the employed methods to the excipients present in pesticide formulations in large amounts.

Multi-class pesticide analysis in cannabis oil using coated blade spray and solid-phase microextraction with liquid chromatography coupled to mass spectrometry.

The application of solid-phase microextraction (SPME) coupled to mass spectrometry to provide a high-throughput and cost-effective solution to multi-residue analysis of pesticides in cannabis oil samples has not been extensively explored. In this work, the method development steps for the extraction of an initial target list of 74 pesticides from cannabis oil via SPME for analysis with both LC-MS/MS and coated blade spray (CBS) are presented. The exploration of a washing step to remove adhered oil whilst minimally desorbing extracted analytes along with the implementation of central composited design investigation to examine compound extraction kinetics in the non-polar matrix yielded a workflow that was validated via both instrumental techniques. Of the initial target list, 37 pesticides were found to be suitable for screening or quantitation via CBS with performance validated via LC-MS/MS. The majority of compounds were found to meet the EU SANTE guidelines for analysis (i.e. linearity, precision, accuracy) whilst reaching limits of quantitation below or at Health Canada minimum regulatory limits (majority at 10 ng/mL). Examination of factors contributing to poor quantitation of pesticides via CBS are shared and explored, such as contributing isobaric interference sourced from plant byproducts and carrier oil, and comparison of signal-to-noise values achieved in cannabis oil when compared to the cannabis-free medium-chain triglyceride oil used as a carrier oil to stress the importance of matrix-match method development.

Multiresidue pesticide quantitation in multiple fruit matrices via automated coated blade spray and liquid chromatography coupled to triple quadrupole mass spectrometry.

Application of ambient mass spectrometry techniques to accelerate analysis of pesticides in produce, with technique validation via chromatographic separation, has not been explored extensively. In this work, coated blade spray (CBS) was used to provide freedom of instrumental choice for a multiresidue panel of pesticides in apple, blueberry, grape, and strawberry through direct-coupling with mass spectrometry (MS) and liquid chromatographic (LC) analyses. For all four matrices, >125 compounds were found to meet European Union guidelines concerning linearity, precision, and accuracy while both CBS-MS/MS and SPME-LC-MS/MS methods achieved limits of quantitation below their minimum regulatory limits. Additionally, results for samples containing residues (n = 57) yielded good agreement between instrumental methods (percent differences < 20% for 73% residues), supporting CBS as a stand-alone technique or complement to LC confirmation of pesticides in fruit matrices.

Breaching the 10 Second Barrier of Total Analysis Time for Complex Matrices via Automated Coated Blade Spray.

In the development of modern analytical workflows, parameters such as sample turnaround time, cost of analysis, and ease of use must be prioritized. Automation enables reductions in total analysis time, human intervention, and cost per sample. In this report, a suitable automated coated blade spray (CBS) workflow is proposed for the screening and quantitation of multiple substances (i.e., drugs of abuse and pesticides) in complex matrices. In an attempt to reduce the total sample analysis time, several parameters were investigated, including tandem mass spectrometry (MS) dwell time, CBS spray time, and extraction time. Solid-phase microextraction (SPME) method parameters are explored, such as reduction of extraction time for increased signal-to-noise. Model compounds with a moderately wide range of molecular weights (150-500 Da), polarities, and structural diversity were selected in order to monitor analytical figures of merit during method optimization. The resultant automated CBS method proved capable of analyzing the model compounds in human urine in under 10 s total analysis time with excellent accuracy (95-120%) and precision (RSD < 12%). As an application, an automated method for the screening and quantitation of more than 150 pesticides from apple juice was demonstrated on both triple quadrupole and orbitrap instruments in under 15 s total sample analysis time.