Residues of nine insecticides and two fungicides in raw and processed tomatoes

Abstract

The objective of this study was to determine preharvest intervals for nine insecticides (acephate, azinphosmethyl, carbaryl, demeton, diazinon, dimethoate, endosulfan, malathion, and permethrin) and two fungicides (captafol and chlorothalonil) in order to produce raw tomato fruit and juice with residue levels below 0.1 and 0.01 mg kg-1, respectively. Over a four-year period (1985-88) ripe tomato fruit was commercially treated with these 11 pesticides and harvested on days 0,1,3 and 6, 7, or 8 after spraying. Both raw fruit and processed juice were then analyzed for residues. Residues of the 11 pesticides fell below 0.1 mg kg-1 in juice and eight declined below 0.1 mg kg-1 on raw fruit during the 0- to 8-d harvest period. The exceptions on raw fruit were chlorothalonil (1987), diazinon, and azinphosmethyl (1987). Residues of seven insecticides and the two fungicides fell below 0.01 mg kg-1 in juice, but only acephate and demeton declined below 0.1 mg kg-1 on raw fruit in the 6- to 8-d period. Carbaryl and malathion were the two insecticides which failed to decline below 0.01 mg kg-1 in the juice. Hence, many of the pesticides required a longer preharvest interval than 6-8 d to attain a reduction in residue to 0.01 mg kg-1. Commercially processed tomato products were also analyzed from domestically grown fruit, many of which had been treated with one or more of the pesticides in this study but at unknown intervals. Tomato products including chili, catsup, juice, paste, and sauce were analyzed for a wide range of pesticides and no detectable residues were found.