Study On The Main Impurities In The Technical S-triazine Herbicides

The judgment criteria of pesticide should include effectiveness and safety.The contents of some impurities in pesticides were less,but they may cause teratogenesis,cancer or environmental pollution and may be harmful to human body.Therefore,it is usual to have a strict control of the impurity in the technical pesticide in the world.Most countries require pesticide manufacturers to provide the names and the structures of the impurities which account for more than 0.1%or may be toxic to mammals and environment significantiy, when pesticides are applied for registration.S-triazine herbicide is one of the presently widely used herbicides in the world,which play an important role in the agriculture.At present,study on impurities of s-triazine herbicide is rarely reported in the world.The reports of the impurities in s-triazine herbicides were basically on the deduction of the possible structures by GC-MS,and no further confirmation had been done towards the results.In this thesis,we chose simazine,simetryne and terbutryne as investigation objects. Firstly,the main impurities(more than 0.1%)in technical simazine,simetryne and terbutryne were identified by GC-MS.The possible configurations of the main impurities were deduced from mass spectrums and the backgrounds of production process.Then,the possible compounds were preparation by chemical methods.The structures of the compounds were identified by IR,¹H-NMR,¹³C-NMR and MS.By comparing the MS spectrums of the possible compounds and that of the impurities in technical,it was found that the structural information was in common.By further comparing the retention time of the profounds and that of the impurities,the main impurities in technical simazine,simetryne and terbutryne were conformed.The research showed that the main impurity in technical simazine was 2-chloro-4-ethylamino-6-isopropylamino-s-triazine;the main impurities in technical simetryne were 2-chloro-4,6-bis(ethylamino)-s-triazine and 2,4,6-tri(ethylamino)-s-triazine; the main impurities in technical terbutryne were 2-methylthio-4,6-bis tert-butylamino)-s-triazine,,4-bis(methylthio)-6-tert-butylamino-s-triazine,2-methylthio-4-ethylamino-6-iso-propylamino-s-triazine and 2-methylthio-4,6-bis(ethylamino)-s-triazine.Finally,the quantitative analysis method of simetryne and two main impurities was set up by the optimization of gas chromatographic conditions.