|Han, Lijun - China Agricultural University|
|Matarrita, Jessie - Universidad De Costa Rica|
Submitted to: Journal of Separation Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/27/2016
Publication Date: 10/25/2016
Citation: Han, L., Sapozhnikova, Y.V., Matarrita, J. 2016. Evaluation of a new carbon/zirconia-based sorbent for the cleanup of food extracts in multiclass analysis of pesticides and environmental contaminants. Journal of Separation Science. 39(23):4592-4602.
Interpretive Summary: Residual analysis of pesticides and other contaminants in highly pigmented and fatty foods is a challenging task because of the high complexity of food matrices. Efficient cleanup of food extracts is critical in removing interfering matrix components, which reduce method performance and compromise the quality of the results. A new sorbent SupelTM QuE Verde was recently introduced by Supelco, combining fat and pigment removing properties. We evaluated the new cleanup material in both highly pigmented (kale, avocado) and fatty (avocado, pork, salmon) foods for analysis of 117 pesticides and environmental contaminants. The new sorbent provided efficient removal of chlorophyll and lipids/fat, and enabled residual analysis of most of the selected contaminants at or below tolerance levels in foods. The new high-throughput method is fast, efficient and can be implemented in any laboratory for residual analysis of contaminants in pigmented and fatty foods.
Technical Abstract: A novel carbon/zirconia based material, SupelTM QuE Verde (Verde), was evaluated in a filter-vial dispersive solid phase extraction (d-SPE) cleanup of QuEChERS extracts of pork, salmon, kale, and avocado for residual analysis of pesticides and environmental contaminants. Low pressure (LP) GC-MS/MS was used for fast analysis of 65 pesticides and 52 environmental contaminants, consisting of 16 flame retardants, 15 polycyclic aromatic hydrocarbons (PAHs), 7 polybrominated diphenyl ethers (PBDEs), and 14 polychlorinated biphenyls (PCBs). The amount of 180 mg sorbent per 0.6 mL extract in filter vial d-SPE was found the optimum in terms of achieving satisfactory removal of co-extractives and recoveries of analytes, especially for structurally planar compounds. For those analytes that were partially retained by Verde, normalization to an internal standard resulted in 62-107% recoveries. The removal efficiency of co-extracted chlorophyll was 93% for kale and 64% for avocado based on UV/Vis absorbance. Addition of Verde to PSA and C18 in d-SPE cleanup resulted in 38% more removal of GC-amenable co-extractives in avocado, 30% in kale, 39% in salmon, and 50% in pork. The developed method was validated at three spiking levels (10, 25, and 100 ng/g), and 70-120% recoveries with less than or equal to 20% RSD were achieved for 96 (83%) out of 117 analytes in pork, 79 (69%) in salmon, 71 (62%) in kale, and 75 (65%) in avocado.