In order to protect the food safety, it is important to establish detection criteria of pesticide residues and methods to improve the accuracy for measuring the concentration of the targets. In Japan, the detection criteria of pesticide residues are established as the Positive List System by the Ministry of Health, Labor and Welfare, as well as the standard test methods. For monitoring of pesticide by LC-MS/MS, recovery rate should be the critical issue in addition to sensitivity. Generally, standard addition method as well as matrix-matched calibration curve are useful techniques rather than absolute calibration method in order to reduce matrix effects; however, these techniques are not always appropriate methods since each sample requires its independent calibration curve, respectively, for a wide variety of samples.
In this report, we introduce the results of investigation for basic parameters around the ESI ionization to avoid matrix effects and to maximize recovery rate of target pesticides using absolute calibration methods.