Pesticides pirimiphos-methyl

Brealey, C.J., Walker, C.H., and Baldwin, B.C. (1980). A Esterase activities in relation to differential toxicity of pirimiphos-methyl. Pesticide Science 11, 546-554. 

Among organophosphates dichlorvos (2,2-dichlorovinyl dimethyl phosphate) and pirimiphos methyl (0-[2-(diethylamino)-6-methyl-4-pyr-imidinyl]0,0-dimethylphosphorothioate) are important contaminants for the durum wheat industry. Dichlorvos is one of the most widely used pesticides worldwide in the storage of many products, such as com, rice, and durum wheat, finding widespread use in most European countries... 

The possibility of detecting a phosphotionate pesticide in durum wheat has been also investigated. The determination was accomplished via chemical oxidation of the phosphothionate molecule both in buffer and in matrix extract solution optimizing the experimental parameters (reagents concentration and reaction time). The procedure was then applied to standardize the pirimiphos methyl detection obtaining the calibration curves under different conditions. The LOD with matrix extract was 50 or 100 ng/mL, depending on the extract % addition, which allowed the detection of samples contaminated at the MRL — 5 mg/kg. The samples mean recovery was 70.3% and no false positive samples were detected [49]. 

The applications described above, coupled with the realization of a dedicated portable instrumentation and software, represent a user-friendly analytical tool dedicated to durum wheat safety. Moreover, all the applications are based on the use of one single type of thick-film SPE facilitating the overall procedure for the final user that has to store and handle one single type of transducer. The developed device, which consists of the hand-held potentiostat, the multiplexer for eight-channel control and a dedicated software, can be used to detect OPs pesticides, such as dichlorvos and pirimiphos methyl at contamination level below the MRL settled by the European Union, OTA, and also amplified DNA of F. culmorum. 

In a study using a human neuroblastoma cell line, mixtures of three different organophosphates (azinphos-methyl, diazanon, and dimethoate), and mixtures of an organic phosphate (pirimiphos-methyl) and a benzim-idizole fungicide (benomyl) showed greater toxicity toward protein synthesis than the individual pesticides. I21 The authors of the study concluded that it is not feasible to predict the toxicities of pesticide mixtures on the basis of the toxicities of the single components. 

Organophosphorus pesticides Acephate , Azinphos-methyl , Chlorpyrifos , Chlorpyriphos-methyl , Diazinon , Dichlorvos (DDVP), Dicrotophos , Dimethoate , Disulfoton , Ethoprop , Eenamiphos , Eenitrothion , Fenthion , Fosthiazate , Malathion , Methamidophos , Methidathion , Methyl-parathion , Mevinphos , Naled , Oxydemeton-methyl , Para-thion , Phorate , Phosalone , Phosmet , Pirimiphos-methyl , Profenofos , Terbufos , Tetrachlorvinphos , Trichlorfon . 

Figure 11.6 Mean honey bee mortality, pesticides, and lEH values registered in CAS, GRA, and OZZ monitoring stations in May, 1998 (DTO = dimethoate, PRM = pirimiphos-methyl, MEP = methyl-parathion, TAM = methamidophos, OME = omethoate, FTN = feni-trothion).

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