Analysis of Pesticides

To protect food safety, it is important to establish detection criteria for pesticide residues and methods to improve accuracy when measuring the concentration of the target substances. Generally, the standard addition method and matrix-matched calibration curve are more useful techniques for reducing the matrix effect than the absolute calibration method. However, these techniques are not necessarily simple, since an independent calibration curve is required for each sample of a wide variety of samples. In this report, we introduce an LC/MS/MS analysis technique which is capable of obtaining high recovery accuracy with the absolute calibration method.

One of the issues cited in the analysis of pesticide residues in food using GC/MS/MS is the matrix effect that causes abnormal recovery rates. The matrix effect is a phenomenon where the matrix sample has a higher response for pesticide residues than the standard sample. It occurs because adsorption and decomposition occur at the active site with standard samples where there is no matrix, but in cases where there is a matrix the matrix coats the active site (Fig. 1). The method of adding an analyte protectant (AP) is used as a countermeasure to reduce the matrix effect. Polyethylene glycol (PEG) 300 can be cited as a representative AP. K. Mastovska et al. have also reported a method where a sample of mixed ethylglycerol, sorbitol, and gulonolactone are used as a useful AP mixture. 1) In this article, we report on the results of studying a method for coping with matrix effects when PEG300, and a combination of AP, were used.

Cases have been reported of health problems due to foods contaminated with pesticides, and there is currently heightened interest in food safety countermeasures. Using a detector with high selectivity for specific components, or a mass spectrometer highly capable of qualitative analysis are effective when analyzing trace components in foods and other samples in which there are many impurities.
The FPD-2030 flame photometric detector, which is installed in Nexis GC-2030 gas chromatograph, has the world's highest level of sensitivity* thanks to the optimized nozzle shape and the advanced dual focus system.
In the analysis of pesticides in foods, this detector provides high sensitivity and high stability.
In this Application News, we introduce an analysis of organophsphorus pesticides using Nexis GC-2030 gas chromatograph, which is equipped with the FPD-2030.