QuEChERS Clean-up Tubes-15 ml, AOAC Method, 1200 mg mgSO4, 400 mg PSA, 50 pc/PAK

QuEChERS (pronounced “catchers”) stands for Quick, Easy, Cheap, Effective, Rugged and Safe - the qualities that describe this sample preparation method for food substances. The technique is quite simple, involving a minimum of steps, and is effective for the cleanup of complex samples. QuEChERS is an upgraded version of SPE. They have similar functions, but the preparation method of QuEChERS is much easier. With QuEChERS, you can prepare your samples for multi-class, multi-residue analysis while saving time and money. In the United States, the Association of Official Analytical Chemists (AOAC) has published its 2007 .01 Method while the European equivalent, the EN 15662 2007, uses similar methodology .

AOAC, EN methods add buffer salts in the original OR method to ensure effective extraction of pH-sensitive compounds, to reduce degradation of sensitive compounds (such as pesticides that are not stable to alkali or acid), and to expand the application range of broad spectrum of this method for food matrices. In the first step of extraction, citrate is used as a buffer to adjust pH to 5-5.5, allowing most pesticides that are not stable to acid or alkali to remain stable. For alkali-sensitive compounds, the stability can be improved by adding a small amount of formic acid after cleanup. For target compounds containing acidic pesticides (phenoxy alcohols), sample injection analysis can be performed directly (skipping the SPE dispersion step), as the acidic group binds to the PSA adsorbent, resulting in reduced recovery rate. For dry samples such as cereals, dried fruits, tobacco, or tea, water should be added before the extraction to reduce the interaction between pesticide and matrices to ensure adequate phase separation. Even high-fat samples such as avocados or olive oil can be analyzed this way. However, for strong nonpolar pesticides, the recovery rate can only reach 70% due to phase separation entered lipid phase. Those lipids extracted together can be removed by freezing or adding a C18E adsorbent.
Nowadays, QuEChERS method has been applied in more and more fields, such as detection of PAHs in meat products, detection of various veterinary drug residues, detection of dicyandiamide, etc. The development of these applications has greatly reduced the pretreatment workload of chromatographers.