Thermo Fisher Scientific has released a white paper on the Analytical Challenges for Pesticide Residue Analysis in Food. The paper shows some of the critical stages, advantages, and limitations of the most widely used sample preparation methods. "For comprehensive analysis of 100,000’s of different pesticide-commodity combinations, the analyst will typically use multi-analyte methods based on both GC-MS and LC-MS techniques together with a number of different single residue methods."
Despite being outside of the scope of this particular essay, the white paper recognizes the importance of collection and transporting the sample back to the lab, but focuses more on the steps taken inside the lab once the sample is inspected and accepted.
According to the article, there are 5 critical steps in the analytical workflow:1. Sample Preparation:
removing parts of the sample that are not going to be analyzed, thus transforming the lab sample into an analytical sample.2. Sample Processing or Comminution:
homogenising the sample (e.g., cutting, grinding, mixing) 3. Extraction:
extraction or transfer of analytes into the extracting phase (usually a solvent) 4. Cleanup (optional):
removing non-specific matrix co-extractives 5. Analytical determination
(separation, detection, identification and quantification of target analytes) and reporting of the results
The paper goes on to explain that all multi-residue methods will have limitations and that there is no universal best method for all laboratories, as every individual laboratory will have to deal with its own specific factors such as "pesticide-matrix combinations to be tested, customer requirements, guidelines or regulations to be complied with (...), etc."
Should you require any further information regarding food or other sample preparation, please contact our Sales Team.