Supel™ QuE Verde – A Novel QuEChERS Sorbent for Planar Pesticides in Green Matrices

The 'Quick, Easy, Cheap, Effective, Rugged, Safe' QuEChERS approach changed the face of solid phase extraction for food analysis by using bulk salts and SPE sorbents for extraction and cleanup of food and agricultural samples. This widely accepted technique has provided analytical laboratories with fast, cost effective sample cleanup prior to pesticide residue, veterinary drug, PAH, PCB, and PBDE analysis.

When analysing compounds in green samples by GC, the removal of chlorophyll is a necessity. Chlorophyll, a pigment of high molecular weight, is known to quickly cause fouling of injection liners and GC columns due to buildup at the injection port and GC column head. Traditional GCB possesses a planar, graphitic surface, allowing for removal of nearly 100% of chlorophyll from green samples. Unfortunately, when analysing planar aromatic compounds such as hexachlorobenzene and chlorothalonil in green samples, poor analyte recoveries are observed. The interaction between the planar structure of the GCB and these planar pesticides causes unwanted retention on the carbon sorbent. 

Supel™ QuE Verde for QuEChERS combines a novel carbon with zirconia coated silica (Z-Sep+) to provide an optimum balance between analyte recovery and colour removal. This sorbent combination has been shown to provide recoveries in the range of 70% to 120% of even the most challenging planar pesticides while maintaining >95% pigment removal in high chlorophyll matrices.

Supel™ QuE Verde is a mixture of an improved graphitized carbon black (GCB), Z-Sep+, and primary-secondary amine (PSA). The improved GCB has been optimised to balance chlorophyll removal and improve recoveries of planar pesticides. Z-Sep+ is a silica that is functionalised with both zirconia and C18. Zirconia retains some fats and carotenoids, while C18 retains hydrophobic interferences. The PSA in the mix functions to remove acidic interferences. When used to clean samples containing chlorophyll, this sorbent blend will provide better recovery of planar pesticides than sorbents containing traditional GCB. To learn more about this product, and to evaluate a sample, please click here.