The Application Notebook
Volume 0, Issue 0
Carbendazim is a widely used, broad-spectrum fungicide to control mold on citrus crops.
Carbendazim is a widely used, broad-spectrum fungicide to control mold on citrus crops. This fungicide is approved for use in Brazil and several other countries, but is not approved for use in the United States or on imported products. This has lead to increased testing of orange juice for pesticide residues.
With recent advancement in multiresidue pesticide screening, methods have been simplified by the introduction of QuEChERS. Both the AOAC Official Method 2007.01 and EN15662:2008 require several manual steps to extract the pesticides of interest (1,2). The AutoMate-Q40 streamlines the QuEChERS method by automating the addition of acetonitrile (ACN) and buffering salts; shaking, mixing, and centrifuging the sample; transferring the sample to a dispersive solid phase extraction (d-SPE) tube using an air displacement pipetter (ADP); and finally measuring and delivering the extract. The intent of this poster is to evaluate the performance of the AutoMate-Q40 by monitoring carbendazim in orange juice. The target pesticide will be analyzed using LC–MS-MS.
Figure 1 shows the flow chart for the AOAC QuEChERS extraction procedure using the AutoMate-Q40 without the dSPE cleanup step.
Figure 1: AutoMate-Q40 extraction procedure for orange juice.
A precision and accuracy study was performed using the AutoMate-Q40. A 6 µg/mL stock pesticide standard was used to fortify the samples through the AutoMate-Q40 spiking system. The orange juice samples were spiked with 25, 150, and 250 µL of the pesticide standard yielding 10 ng/mL, 60 ng/mL and 100 ng/mL check samples. These QC samples were quantitated against their corresponding matrix-matched calibration curve.
Figure 2: AutoMate-Q40 automated QuEChERS platform.
Table I demonstrates the excellent recoveries achieved when using the AutoMate-Q40, ranging from 91.4% to 94.7%. The AutoMate-Q40 also demonstrates greater precision ranging from 3.3% to 6.2% RSD.
Table I: Carbendazim recovery data
(1) AOAC Official Method 2007.07 Pesticide Residues in Food by Acetonitrile Extraction and Partitioning with Magnesium Sulfate. Gas Chromatography/Mass Spectrometry and Liquid Chromatography/Tandem Mass Spectrometry, First Action 2007.
(2) European Committee for Standardization/Technical Committee CEN/TC275 (2008), Foods of plant origin: Determination of pesticide residues using GC–MS and/or LC–MS-MS following Acetonitrile extraction/ partitioning and cleanup by dispersive SPE QuEChERS-method.
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