Investigation of Quick and Simple Analysis Method by Fourier Transform Infrared Spectroscopy for Multiple Pesticides Residue Analysis

Abstract

In this study, we have developed the rapid and simple analytical method by FT-IR for dithiocarbamate pesticides: Mancozeb, Maneb, Ziram, Propineb and Thiuram. These pesticides are used in various crops as insecticides and fungicides. Spirodiclofen, Chlorfenapyr and Cyenopyrafen which were often used for citrus fruits were also examined. The developed analytical method consists of the following sequence of operation: wiping with water-soluble fiber, filtration concentration, and FT-IR analysis (transmission method). Linear calibration curves were obtained for all pesticides tested. In addition, the detection lower limit for each pesticide was low enough to comparison with the pesticide maximum residue level. Especially, the average recovery rate of dithiocarbamate pesticide in tomato was more than 70%. Kiyomi and green peppers also had average recovery rates of 60% or more. Conversely, the recovery rate of plums was low, and the average recovery rate was less than 50%.
PLS quantitative model for calculating the total amount of dithiocarbamate pesticide (carbon disulfide conversion value) was also prepared. By using this PLS quantitative model, it was possible to measure the total amount of dithiocarbamate pesticides even if more than two dithiocarbamate pesticides are used. These results shows that this method is enable to do rapid screening of pesticides on site and it has great potential for application in food safety and security.