QuEChERS sample preparation

The QuEChERS method is a streamlined approach that makes it easier and less expensive for analytical chemists to examine pesticide residues in food. 

The sample preparation and clean-up processes for pesticide analysis have not been standardized, but a clear trend over the recent years indicates a strong 

Less time is required to process samples, compared to other techniques allowing a higher sample throughput, typically 15 samples can be manually prepared within 1 h. 

Requires less handling of extracts than other techniques, fewer steps are required. 

Less sorbent material is needed for smaller sample sizes. 

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Golge, O., Kabak, B. Evaluation of QuEChERS sample preparation and liquid chromatography-triple-quadrupole mass spectrometry method for the determination of 109 pesticide residues in tomatoes. Food Chem. 176, 319-332 (2015)... 

Bruzzoniti, M.C., Checchini, L., De Carlo, R.M., Orlandini, S., Rivoira, L., Del Buhba, M. QuEChERS sample preparation for the determination of pesticides and other organic residues in environmental matrices a critical review. Anal. Bioanal. Chem. 406, 4089-4116 (2014)... 

Table I. Grouping of plant products for QuEChERS sample preparation.

Kwon, H., Lehotay, S. J., and Geis-Asteggiante, L. 2012. Variabibty of matrix effects in hquid and gas chromatography-mass spectrometry analysis of pesticide residues after QuEChERS sample preparation of different food crops. J. Chromatogr. A 1270 235-245. 

Lehotay, S. J. 2011. QuEChERS sample preparation approach for mass spectrometric analysis of pesticide residues in foods. Methods Mol. Biol 747 65-91. 

Chen, G., Cao, R, and Liu, R. 2011. A multi-residue method for fast determination of pesticides in tea by ultra performance liquid chromatography-electrospray tandem mass spectrometry combined with modified QuEChERS sample preparation procedure. Food Chem. 125 1406-1411. 

In combination with the QuEChERS, sample preparation GC-MS/MS using H-SRM turned out to provide the required sensitivity and certainty for a multi-component quantitation of trace pesticides in food for a high throughput of samples. 

Pesticide analysis with multi-methods using single and triple quadrupole instruments and QuEChERS sample preparation... 

QuEChERS (quick, easy, cheap, effective, rugged, and safe) is an acronym used as the name of a sample preparation procedure, generally based on a combination of solvent extraction of analytes from a sample and dispersive SPE applied for cleaning an extractant. 

QuEChERS, which stands for Quick, Easy, Cheap, Effective, Rugged, and Safe, is one of those new-generation sample preparation methods for pesticide multiresidue analysis [1]. Although very recently introduced (development between 2000-2002, publication in 2003), the method has been widely embraced by the international pesticide residue analysts community and is already being used in numerous laboratories worldwide [2-6]. Aiming to deliver an economical and... 

Sampling, sample handling, and storage and sample preparation methods are extensively covered, and modern methods such as accelerated solvent extraction, solid-phase microextraction (SPME), QuEChERS, and microwave techniques are included. Instrumentation, the analysis of liquids and solids, and applications of NMR are discussed in detail. A section on hyphenated NMR techniques is included, along with an expanded section on MRI and advanced imaging. The IR instrumentation section is focused on FTIR instrumentation. Absorption, emission, and reflectance spectroscopy are discussed, as is ETIR microscopy. ATR has been expanded. Near-IR instrumentation and applications are presented, and the topic of chemometrics is introduced. Coverage of Raman spectroscopy includes resonance Raman, surface-enhanced Raman, and Raman microscopy. 

For analytical studies, sample preparation is necessary to determine the composition of phenolic compounds in these matrices. The most widely used extraction system is UAE, which is an inexpensive method since it involves the use of low organic solvent and requires short extraction times. Multi-analyte methods with minimal sample manipulation are demanded. However, vegetables and fruits are very complex matrices and hence sample extraction and clean-up treatments must be carefully developed to reduce manipulation and total analysis time. Therefore, QuEChERS could be a useful tool for this purpose in future applications. 

An alternative sample preparation is based on the QuEChERS (Quick Easy Cheap Effective Rugged Safe) technique [14]. In this the sample is extracted into acetonitrile and magnesium sulfate, sodium chloride and citrate buffer salts at pH 5-5.5 are added, the mixture is shaken and then centrifuged to separate the phases. When applied to honey [15] the samples, containing isoproturon-d6 as an internal standard, were diluted with water and homogenized before addition of the QuEChERS salts described above, and acetonitrile. After extraction, centrifugation... 

The popular multi-component methods with short sample preparation and extract clean-up such as QuEChERS require special care for the chromatographic... 

Lehotay, S.J. (2013) Revisiting the advantages of the QuEChERS approach to sample preparation, oiJine presentation, webinar Separation Science, http //www.sepscience.com (accessed 14 May 2014). 

Special focus has been set to the widely used and popular sample preparation methods as there are the pressurized liquid extraction (RLE), the thermal extraction of materials and food (outgassing), and in detail on the QuEChERS pesticide sample preparation used for GC-MS and LC-MS. As a consequence of the higher matrix load of these extracts and the recommended GC injection techniques, concurrent backflush, preventive maintenance and inlet deactivation became current topics of discussion. Olfactometry solutions have been added for apphcations in flavour analysis. 

The QuEChERS method was invented and described for the first time in 2003 by Anastassiades et al. [98] as a fast, simple, inexpensive, and convenient preparation procedure for fruit and vegetable samples used for pesticide multiresidue analysis. Currently, this methodology is used for determinations of pesticides, pesticide residues, and other compounds of environmental concern such as phenol derivatives, perfluorinated compounds, and chlorinated hydrocarbons pharmaceutical compounds in food and agricultural matrices and environmental samples such as soil, sediments, and water (see for example [99-102]). 

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