QuEChERS Method for Pesticide Residue Analysis

QuEChERS significantly improves laboratory efficiency and throughput. This procedure requires only small quantities of solvent and is capable of generating recoveries of 70-120% with RSDs <5% for a wide range of compounds.

A process in two steps:

1. Extraction

• Solvent extraction techniques are designed to achieve maximum yield of analytes from the base matrix.
• Solvent selection is important to minimize co-extracting compounds.
• Analytes are extracted from the matrix with acetonitrile and salts/buffers.

2. Cleanup

• Sample cleanup is necessary to reduce interferences.
• Interferences can damage analytical instrumentation and complicate analyte identification and quantification.
• The use of PSA, C18, GCB (Graphitized Carbon Black) or Z-Sep sorbents allow removal of sugars, lipids, sterols, organic acids, proteins, carotenoids, chlorophyll and other pigments prior to a GC-MS/MS or LC-MS/MS analysis.

1. Homogenize sample
2. Transfer sample to 50mL tube
3. Add ACN and internal standard and shake for 1 min
4. Extraction: Add extraction salts and centrifuge (55227-U for EN15662:2008 and 55234-U for 2007.01 AOAC)
5. Cleanup: Transfer supernatant to cleanup tube
6. Shake and centrifuge
   a) LC-MS/MS Analysis: Dilute extract with mobile phase
   b) GC-MS analysis: Analyze directly or after solvent exchange

QuEChERS Selection Guide

Products for the Extraction Step