Submitted to: Analytica Chimica Acta
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/3/2014
Publication Date: 4/12/2014
Publication URL: http://handle.nal.usda.gov/10113/58770
Citation: Han, L., Sapozhnikova, Y.V., Lehotay, S.J. 2014. Streamlined sample cleanup using combined dispersive solid-phase extraction and in-vial filtration for analysis of pesticides and environmental pollutants in shrimp. Analytica Chimica Acta. 827:40-46. http://dx.doi.org/10.1016/j.aca.2014.04.005. Interpretive Summary: International food trade is a $1.4 trillion global market, and monitoring of chemical residues is often conducted to verify that the food meets regulatory requirements. Fast, inexpensive, and simple high quality methods of analysis are needed to provide high sample throughput in an effective and efficient process. In this work, the “quick, easy, effective, rugged, and safe” (QuEChERS) approach to sample preparation has been further streamlined by combining sample cleanup with in-vial filtration using a novel device, which eliminates the need for a more time-consuming centrifugation step. Other novel aspects included the use of a new salt to simplify the initial sample extraction step, comparison of newly-introduced sorbents for cleanup, and multi-application to pesticides and environmental contaminants simultaneously, which are commonly done in separate methods. The in-vial filtration cleanup approach is being commercially introduced, and this streamlined method is expected to be implemented by many laboratories worldwide to more efficiently monitor chemical residues in food.
Technical Abstract: A new method of sample preparation was developed and is reported for the first time. The approach combines in-vial filtration with dispersive solid-phase extraction (d-SPE) in a fast and convenient cleanup of QuEChERS (quick, easy, cheap, effective, rugged, and safe) extracts. The method was applied to simultaneous analysis of 42 diverse pesticides and 17 environmental contaminants, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls (PCBs), and flame retardants, in shrimp as the sample matrix. Final extracts were analyzed by both low-pressure gas chromatography - triple quadrupole tandem mass spectrometry (LPGC-MS/MS), and high-performance liquid chromatography – triple quadrupole tandem mass spectrometry (HPLC-MS/MS) to provide a wide scope of analysis for targeted analytes. During method development, several different commercial sorbents for d-SPE were investigated and compared with respect to analyte recoveries. The method was validated at 10, 50, and 100 ng/g spiking levels (10-fold lower for PCBs), and the results for nearly all analytes were between 70-115% recoveries with less than or equal to 17% relative standard deviations. The method was shown to be simple, fast, and effective for multi-application analysis of chemical residues in the representative food and environmental marker matrix.