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Introduction This work describes the development of a supercritical fluid chromatography(SFC)method for the separation of a multipesticide sample.Connecting the SFC to a Triple Quadrupole MS and optimization of the necessary MS parameters is discussed.Performance parameters of the final method,such as limits of detection(LOD),limits of quantification(LOQ),linearity,retention time,and area RSD are determined.The obtained SFC/QQQ MS method is further optimized for the determination of pesticides in a complex food matrix.Several gradients of different steepness are applied to the analysis of a vegetable matrix spiked with different concentrations of a multi-pesticide standard.The optimum separation conditions are determined by software-aided batch comparison to identify the gradient with the lowest matrix impact.Methods The final optimized SFC method for the separation of the multi-pesticide sample was done on a NH2-column at a flow rate of 3 mL/min in a gradient run with methanol as organic modifier.The column is directly connected to a splitter assembly,containing two combined splitters and the flow is split to the MS and to the backpressure regulator of the SFC module.Results The development and optimization of a multi-pesticide method for SFC comprising different columns,modifiers and gradients is shown.The method,combining best separation and shortest run time was used for the further optimization of the connection to the Triple Quadrupole MS.The connection of SFC and MS was done by splitting the flow and adding a make-up flow for constant introduction into the MS ion source and proper ionization.The automated and software aided optimization of the MS ion source parameters are described.The used multi-pesticide sample comprised 17 pesticide compounds.For all compounds the achieved linearity as better than 0.999,LOQs were typically below 2.9 ppm,retention time RSDs below 0.4%and area RSDs below 4%.The obtained method was used to determine the matrix effect for SFC/MS coupling with electrospray ionization.Therefore,a standard pesticide solution of different concentrations and spiked rocket samples were analyzed and the results were compared.Finally,a standard and spiked calibration from 10 – 100 ppb was evaluated.Matrix effects were found in the typical recovery range of 70 – 120%and LOQs were at 10 ppb,which meet typical requirement for quantitative determination of pesticides in food matrix.Novel Aspect Separation of a multi-pesticide sample in a very short run time,which is faster than typical RP-HPLC methods.