The QuEChERS Method Facilitates Food Safety Detection
Let’s take a good look at the Quick, Easy, Cheap, Effective, Rugged, and Safe sample preparation technique: QuEChERS, the most efficient solid-phase extraction method for detecting pesticide residues in food. And Hawach QuEChERS products can make procedures easier than ever.
Packed with 50ml empty tube, Hawach QuEChERS extraction salts offer you a pre-weighed anhydrous extract salt. The anhydrous magnesium sulfate is to remove water from the sample matrix, and other buffer salts can provide a suitable pH to make sure that some alkali-sensitive pesticides have a good recovery rate.
When the sample comes with relatively high water content, the recovery rate might be influenced by the QuEChERS buffer salt reacting exothermically with water. Now you don’t need to worry about it because Hawach has separate extraction salt packs available, and you can add buffer salts after adding organic solvents.
You don’t need the specialized glassware when you use QuEChERS extraction salts as well. Free-flowing extraction salts and salt packets can perfectly fit into the extraction tubes and make transferring the salts to your sample neat and easy.
Food safety problem
Environmental pollution caused by unreasonable use of pesticides has caused widespread concern. So does food safety. With the enhancement of environmental awareness and the rapid development of the economy, the governments of various countries have paid more and more attention to the monitoring of pesticide residues in the environment and food. Strengthening research on pesticide residue detection technology has important theoretical and practical significance for the rational use of pesticides, environmental protection, and human health protection.
Sample pretreatment technology is particularly important as a prerequisite and basis for pesticide residue analysis. Some experts analyzed: Nearly 50% of the error in detection and analysis comes from the preparation and processing of samples, and the real source of analysis is less than 30%. And most of the sample pre-processing takes up more than 70% of the entire analysis. Therefore, the development of new technologies for rapid, accurate, safe and efficient sample preparation is becoming more and more urgent.
QuEChERS method was born with the trend, which utilizes acetonitrile to extract pesticide residues in the sample, and the salt is separated by sodium chloride and anhydrous magnesium sulfate, and the extract is purified by anhydrous sodium sulfate and PSA (N-propyl ethylenediamine filler dispersed solid phase extraction, multi-residue analysis with GC, GCΠMS, etc.
General steps of the QuEChERS method:
The first step: salt extraction
The target analyte is first extracted from the sample by a combination of an organic solvent and various salts to extract the analyte of interest from the sample matrix as follows:
a. Mix. Mix samples of fruits or vegetables to be analyzed.
b. Weighing. Weigh the mixed sample.
c. Add. Add salt and acetonitrile.
d. Shake. Shake the tube for 1 minute.
e. Centrifugation. Centrifuge the tube for 5 minutes, and take the supernatant for use.
Step 2: Dispersive solid phase extraction (dSPE)
The sample is further extracted and purified by selecting a suitable dispersed solid phase adsorbent. This step helps to selectively remove excess interferences such as lipids and pigments. Proceed as follows:
a. Add. Add the supernatant obtained in the first step to the dSPE centrifuge tube.
b. Shake. Shake the dSPE tube for 30 seconds.
c. Centrifugation. Centrifuge the dSPE centrifuge tube for 5 minutes.
d. Analysis. Take the supernatant, directly into the GC or LC analysis.