Rapid Screening and Quantification of 534 Pesticides From Food by LC–MS–MS

With more than 800 pesticides currently in use there is growing concern by government agencies about the effect of pesticide exposure on human health. While analytical techniques like GC or GC–MS have traditionally been used for pesticide analysis, LC–MS–MS has become the technique of choice due to speed, increased sensitivity, and reduced sample preparation. The following describes an LC–MS–MS method for the screening of 534 pesticides in food products.

Experimental Conditions

Sample preparation from vegetable, nut and citrus plant materials was done using a standard QuEChERS cleanup procedure and chromatographic separation of the pesticides was achieved using a Phenomenex Synergi Fusion-RP (polar embedded C18) HST 2.5 µm, 50 × 2 mm HPLC column. The method for the AB SCIEX 3200 QTRAP LC–MS–MS system was downloaded from the iMethod Applications store (www.absciex.com/iMethods) and contained all the LC methods, optimized MS settings for each analyte, processing methods, reporting templates, complete method documentation and a Pesticide Standard Kit, iDQuant, that contained 204 compounds distributed in 10 vials. The MS-MS library database of over 601 pesticides was also downloaded, which enabled identification of unknown peaks based on the dual MRM and MS-MS functionality of the QTRAP system.

Figure 1: MRM ion traces for pesticides at 10 ng/mL.

Results

534 pesticides were screened in less than 12 min. Table 1 provides representative recoveries, signal-to-noise ratios and estimated detection limits for selected pesticides spiked at 25 ng/mL in a cucumber matrix. For a full list of recoveries and performance, visit www.absciex.com/iMethods. The final method was verified at different laboratory facilities to ensure the robustness of the method.

Table 1: Representative recoveries, signal-to-noise ratios and estimated detection limits for selected pesticides at 25 ng/mL in a cucumber matrix.

Phenomenex Inc.

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tel: +1 310 212 055 fax: +1 310 212 7768

Website: www.phenomenex.com

AB SCIEX

110 Marsh Drive, Foster City, California 94404, USA

tel: +1 877 740 2129 fax: +1 650 627 2803

Website: www.absciex.com