Selection of Purification Reagents for QuEChERS Method

About HAWACH and QuEChERS method
HAWACH aims to facilitate the lab experiment process and make it easier and simpler. Its extraction kits with 50 ml centrifuge tube and salt pack, purification kits with 2ml/15ml centrifuge tube that contains purification adsorbent, and 2ml/15ml/50ml ceramic proton are widely used in different labs all over the world. The QuEChERS method has been widely used in many aspects of drug residue detection since its inception, from the initial detection of pesticide residues in fruits and vegetables to the detection of veterinary drug residues in aquatic products, the detection of mycotoxins in cereals, the detection of illegal additives in food, etc. The wide variety, the different properties, and the complex composition of the sample matrix increase the detection difficulty to a certain extent. The QuEChERS method or the improved QuEChERS method has a wide range of detection in industrial dyes, alkaloids, illegal addition of drugs, synthetic antioxidants, etc.

Extraction reagent selection
Because acetonitrile has the advantages of easy salting out, compatibility with liquid chromatography instruments, and the ability to precipitate proteins, the extraction solution often selected by traditional QuEChERS methods is acetonitrile or acidified acetonitrile. However, the illegal additives in the food itself contain functional groups and possess different properties. Adjusting the extraction solvent to make the target more easily extracted is a problem to be considered.
In addition, when using the QuEChERS method, a suitable amount of water is generally added to the dry sample (water content <25%) to ensure extraction efficiency. Some researchers have tested the samples such as chili powder, chili paste, tofu skin, etc. adding water-soaking samples. However, some researchers also directly added organic solvent extracts to the yeast and yeast extracts, without adding water for immersion. Therefore, whether to use water to destroy the target and the sample matrix before adding the extraction solution is also a factor to be considered.

Purification reagent selection
The matrix composition of some samples is too complex, and the QuEChERS method will produce a serious matrix effect. In addition to the use of methods such as reducing the sample volume, adding a blank matrix to prepare the standard, adding internal standard correction, etc., selecting efficient purification reagents in the purification is also one of the ways to eliminate matrix effects.

C18, GCB, PSA, and other purification reagents used in the traditional QuEChERS method have been unable to meet the needs of the detection of the addition of illegal substances in food. On the basis of ensuring high recovery, low detection limit, good repeatability, high precision, etc., developing new purification reagents are also the direction that can be developed in the future.

Combined with other instruments
In the current detection of illegally added substances in food, most researchers choose the test mode combining the QuEChERS method and liquid chromatography / liquid chromatography-tandem mass spectrometer. Because liquid chromatography-high resolution mass spectrometry technology has the advantages of accurate qualitative, non-directional unknown screening, high-throughput analysis, minimizing false positives, and the false-negative rate is close to zero, etc. Its applications are becoming more and more popular, making the combination with  QuEChERS become possible. Combining the advantages of the two, it can be foreseen that the sample processing process for the detection of illegally added substances in food in the future is simple, efficient, and accurate.

After continuous updating and improvement, the application of the QuEChERS method in the detection of illegally added substances in food will reduce the cost of conventional testing and improve the efficiency of testing that puzzles researchers.