QuEChERS Multi-Residue Method for Pesticide Analysis
The most popular multi-residue method for pesticide analysis worldwide
QuEChERS, which stands for Quick, Easy, Ch eap, Effective, Rugged, and Safe, is a user friendly and straightforward multi-residue method for the simultaneous analysis of a large number of pesticides in fruits, vegetables, cereals and processed products thereof. The method was first published by Dr. Michelangelo Anastassiades et al. [1] and was introduced at the CVUA Stuttgart in 2003. Dr. Anastassiades, an employee of CVUA Stuttgart and currently Head of the EU-reference Laboratory for special pesticides, elaborated the method during his post-doctoral research at the USDA/ARS-ERRC in Wyndmoor, Pennsylvania (USA) in the laboratory of Dr. Steve Lehotay.
The QuEChERS protocol involves a few very simple steps. It starts with the addition of acetonitrile and the extraction of the homogenized samples by shaking and a partitioning step which is induced by the addition of a salt mixture. The raw extract is then optionally cleaned-up using a dispersive solid phase extraction (dSPE) a simple cleanup concept developed during the development of the QuEChERS method. The final extracts can be directly employed for gas- and liquid-chromatographic measurements. In GC-analysis Analyte Protectants can be optionally added to the extracts and calibration standards to improve chromatographic performance and improve accuracy by equalizing the matrix effects.
QuEChERS typically achieves very high recoveries and low coefficients of variation for a very large number of pesticides within a very polarity range. It has been extensively validated by numerous labs and has been a CEN standard procedure since 2008. The CEN standard was updated in 2018 (EN 15662:2018)
Nowadays QuEChERS is the most widely employed multiresidue method in pesticide residue analysis worldwide. It is estimated that more than 85 % of governmental and private pesticide residue laboratories employ this method.
CVUA Stuttgart employed the QuEChERS protocol in numerous EU proficiency tests (EUPTs) and was always placed in the highest rankings.
The benefits of the method in comparison with traditional methods are:
- Minimal usage of chemical solvents (environmentally friendlier)
- Not labor-intensive (few, simple steps)
- Fast
- No use of chlorinated solvents
- Wide scope of pesticides covered
Due to the fast rate of analyzing samples (e.g. 12 samples in 1 hr.) and the low cost (approx. 1 to 3 € material costs per sample for the sample preparation), this method significantly increases the efficiency and throughput of pesticide residue controls.
Citations
Anastassiades, M., S. J. Lehotay, D. Stajnbaher and F. J. Schenck (2003). "Fast and easy multi-residue method employing acetonitrile extraction/partitioning" and "Dispersive solid-phase extraction for the determination of pesticide residues in produce", Journal of AOAC International 86(2): 412–431.
Anastassiades, M., S. J. Lehotay, K. Mastivska; Evaluation of Analyte Protectants to Improve Gas Chromatographic Analysis of Pesticides (2003) Journal of Chromatography A 1015(1–2):163–84
Further Information