一种快速的农药残留测定方法

Quick, Easy, Cheap, Effective, Rugged, and Safe Approach
for Determining Pesticide Residues
Steven J. Lehotay
Summary
This chapter describes a simple, fast, and inexpensive method for the determination
of pesticides in foods and potentially other matrices. The method, known as the quick,
easy, cheap, effective, rugged, and safe (QuEChERS) method for pesticide residues involves
the extraction of the sample with acetonitrile (MeCN) containing 1% acetic acid
(HAc) and simultaneous liquid–liquid partitioning formed by adding anhydrous magnesium
sulfate (MgSO4) plus sodium acetate (NaAc), followed by a simple cleanup step
known as dispersive solid-phase extraction (dispersive-SPE). The QuEChERS method is
carried out by shaking a fluoroethylenepropylene (FEP) centrifuge tube that contains 1
mL 1% HAc in MeCN plus 0.4 g anhydrous MgSO4 and 0.1 g anhydrous NaAc per gram
wet sample. The tube is then centrifuged, and a portion of the extract is transferred to a
tube containing 50 mg primary secondary amine (PSA) and 50 mg C18 sorbents plus 150
mg anhydrous MgSO4 per milliliter extract (the dispersive-SPE cleanup step). Then, the
extract is centrifuged and transferred to autosampler vials for concurrent analysis by gas
chromatography–mass spectrometry (GC–MS) and liquid chromatography–tandem mass
spectrometry (LC–MS/MS). Different options in the protocol are possible depending on
alternate analytical instrumentation available, desired limit of quantitation (LOQ), scope
of targeted pesticides, and matrices tested.
Key Words: Food; fruits; gas chromatography; liquid chromatography; mass spectrometry;
pesticide residue analysis; sample preparation; vegetables.

原创作者：泉岛公司--色谱消耗品专家