Study on higher sensitivity for analysis of pesticide residues in foods by using GC-MS/MS (1)
Introduction
The analysis of pesticide residues in foods requires the separation and detection of trace amounts of target pesticides present in complex matrices, and therefore, analytical instruments used for such measurements must have high performance. The GC-MS/MS method is effective for simultaneous analysis of multiple components in complex matrices, and is currently used by many analytical institutions as a general analytical method. Naturally, detection sensitivity can differ depending on the analytical instrument used, but various methods exist to increase the sensitivity of conventional analytical methods. For the purpose of increasing sensitivity, it can be effective to apply a sample injection method that is different from the normal hot splitless injection method generally used in GC, and among them, a relatively large number of examples exist using large volume injection (LVI) technology. The Multi Mode Injector (MMI manufactured by Agilent) used in this study allows the selection of various modes, such as cold splitless mode and solvent vent mode, in addition to the general hot splitless mode, depending on the purpose of measurement. However, there are relatively few examples for the application of cold splitless injection methods for the analysis of pesticide residues in food products. In this study, we compare the results of various cold splitless injection methods using MMI to improve GC-MS/MS detection sensitivity by suppressing adsorption and thermal decomposition of the target pesticides in the GC inlet.