Tandem GC/MS Analysis of Pesticides in Food Oils by Large Volume Injection with a Back-flush Option

This application note describes a method to detect pesticides at very low concentrations in challenging food matrices on a routine use gas chromatograph/mass spectrometer (GC/MS). The target concentration was 1 pg/µL injected on-column, or 50 ppt equivalent in matrix. Pesticide analysis is an important aspect of food safety and the sheer number of analyses dictates that the methods used must be reliable, robust, and, given the competitive nature of the food industry, the cost per analysis must be low. Food is a complicated matrix for an analysis, and the chemical complexity of the food makes co-elution of matrix peaks with residues of interest inevitable. Even when using the mass spectrum of a compound of interest, there can be difficulty in determining pesticide contamination, especially at low levels.