Studies on Residual Decomposition Products of Pesticides in Agricultural Products (I)

Residue of Ethylenethiourea (2-Imidazolidinethione) in Agricultural Products

Abstract

Ethylenethiourea (ETU) and ethylene-bis-dithiocarbamate in agricultural products were determined, according to improved Newsomes' method.
The improved analytical method consists of five procedures, extraction with methanol or methanol: water mixture (8:2), conversion to the S-benzyl derivative, clean up with benzene: n-hexane mixture (1:1), trifluoroacetylation, and quantitative mesurement by gas liquid chromatography.
Specific confirmation of the derivative was carried out by mass spectrometry.
The efficiency of the analytical method was applicable to sixteen agricultural products, and was evaluated by taking a good repeatability and taking away an obstraction.
Three samples were found to contain 0.008-0.076ppm of ethylenethiourea, and 0.34-1.21ppm of ethilene-bis-dithiocarbamate.