Determination of Pesticides in Bananas by QuEChERS and LC-MS/MS

This application describes a simple, fast, and cost-effective method for the determination of multi-class pesticides in bananas including one of the most difficult compounds, pymetrozine. The method employs the AOAC version of the QuEChERS procedure, in which 15 g of the homogenized banana sample is hydrated with 5 mL of reagent water to give a sample with > 80% water content. The hydrated sample is extracted by 15 mL of acetonitrile (MeCN) with 1% (v/v) acetic acid (HAc), followed by the addition of 6 g anhydrous magnesium sulfate (MgSO4) and 1.5 g sodium acetate (NaOAc). After shaking and centrifugation, 1 mL of the supernatant is transferred to a 2-mL dSPE tube containing 150 mg MgSO4, 50 mg PSA, and 50 mg C18. The MgSo4 absorbs residual water; PSA removes organic acid and sugars, while the C18 removes fatty acids and other non-polar interferences in the sample. The result is a clean extract for LC-MS/MS analysis. 

This application note was authored by UCT. Please complete the information in the "Download Application Note" box to download the complete article.