Pesticide Residue Methods

Category Others
Class Name Multi-Residue Method
Method Title QuEChERS: A Mini-Multiresidue Method for the Analysis of Pesticide Residues in Low-Fat Products
Method Date 2003/01/01
Method Type Screening, Quantitative
Scope and Application A Multi Pesticide Residue Method for the analysis of a side range of pesticides in low oil / fat crop matrices.
Method Summary The homogeneous and representative subsample is extracted in frozen condition with the help of acetonitrile. After addition of magnesium sulfate, sodium chloride and buffering citrate salts, pH 5 to 5.5, the mixture is shaken intensively and centrifuged for phase separation. An aliquot of the organic phase is cleaned up by dispersive SPE employing bulk sorbents e.g. PSA, GCB as well as MgSO4 for the removal of residual water. PSA treated extracts are acidified by adding a small amount of formic acid, to improve the storage stability of certain base-sensitive pesticides. The final extract can be directly employed for GC and LC based determinative analysis. Quantification is performed using an internal standard, which is added to the extract after the initial addition of acetonitrile. Samples with a low water content (LT 80 pct) require the addition of water before the initial extraction to get a total of ca. 10 mL water. When dealing with samples containing LT 25 pct water e.g. cereals, dried fruit, honey, spices the size of the analytical sample may have to be reduced e.g. 1 to 5 g depending on the load of matrix co extractives expected in the final extracts.
Applicable Concentration Range See Analytical Method
QC Requirements See Analytical Method
Method Performance/Validation See Analytical Method
Method Source QuEChERS Home Web Site
Method SOP PDF icon SOP 
Citation M. Anastassiades, S. J. Lehotay, D. Stajnbaher, F. J. Schenck, Fast and Easy Multiresidue Method Employing Acetonitile Extraction/Partitioning and Dispersive Solid-Phase Extraction for the Determination of Pesticide Residues in Produce, J. AOAC Int., 86 (2003) 412-431