Identification of impurities in technical anilofos and their effect on transplanted rice

Seven impurities, namely, isopropylaniline (III), isopropylacetanilide (V), isopropylchloroacetanilide (VII), oxoanalogue (VIII), dithiodimer (IX), monothiodimer (X), and mercaptoacetanilide (XI), have been identified from technical anilofos. The quantification of each impurity was carried out by comparison with authentic samples of known concentration by GC and HPLC. The structure of authentic samples (synthesized and isolated) was established on the basis of NMR, IR, and MS spectral data. Bioassay of all the detected impurities along with three possible contaminants was carried out on transplanted rice under laboratory conditions. The oxo compound (VIII) was found to have an inhibitory effect on transplanted rice at 1 microg/g of soil.