1.A comparison of the acute toxicity, neuropathology, and electrophysiology of N,N-diethyl-m-toluamide and N,N-dimethyl-2,2-diphenylacetamide in rats.
Verschoyle RD1, Brown AW, Nolan C, Ray DE, Lister T. Fundam Appl Toxicol. 1992 Jan;18(1):79-88.
The insect repellent DEET and the structurally related herbicide diphenamid both cause ataxia associated with a spongiform myelinopathy largely confined to the cerebellar roof nuclei. This local myelinopathy was accompanied by the formation of neuronal cytoplasmic clefts and was produced by a single dose of 1 to 3 g/kg N,N-diethyl-m-toluamide (DEET). These dose levels also produced a severe and often fatal prostration and clear electrophysiological signs of prolonged suppressed seizure activity. Diphenamid produced an identical myelinopathy after doses of 0.8 to 1.5 g/kg but without the severe prostration, suppressed seizures, or neuronal clefts. The effects of diphenamid were shown to be reversible over 3 to 7 days by neuropathological, motor, and auditory evoked response indices. Both compounds caused characteristic changes in auditory evoked response which may be useful in clinical diagnosis. Six other alkyl amides, two of which produce signs of CNS excitation, failed to produce myelinopathy at the maximum tolerated doses.
2.Photo-induced chemiluminescence-based determination of diphenamid by using a multicommuted flow system.
Czescik A1, Malo DL, Duart MJ, Zamora LL, Fos GM, Calatayud JM. Talanta. 2007 Oct 15;73(4):718-25. doi: 10.1016/j.talanta.2007.04.044. Epub 2007 May 10.
This manuscript deals with the application of molecular connectivity calculations to predict the photo-induced chemiluminescent behaviour of the family of herbicides grouped as amides. Several compounds of this group were theoretically studied by means of a general discriminant equation formerly obtained, being 18 of them (plus eight from the chloroacetanilide sub-group) predicted with a high probability as photo-induced chemiluminescent. Empirical confirmation of the chemiluminometric behaviour was performed with some few commercially available amide herbicides. On the basis of these results, a new multicommutation-photo-chemiluminescent method is proposed for the determination of the diphenamid. The method is based on the photodegradation of the pesticide and then the resulting photo-fragment solutions are oxidized by K(3)[Fe(CN)(6)] in sodium hydroxide medium, at room temperature and 80 degrees C, for the photodegradation and chemiluminometric oxidation, respectively.
3.Simultaneous determination of herbicide residues in tobacco using ultraperformance convergence chromatography coupled with solid-phase extraction.
Guo W1, Bian Z, Zhang D, Tang G, Liu W, Wang J, Li Z, Yang F. J Sep Sci. 2015 Mar;38(5):858-63. doi: 10.1002/jssc.201401063. Epub 2015 Feb 4.
A time-saving and organic solvent efficient method to simultaneously determine six kinds of herbicide residues in tobacco using solid-phase extraction for sample clean-up and preconcentration and the highly sensitive ultraperformance convergence chromatography method was developed. Parameters for ultraperformance convergence chromatography, including the choice of stationary phase and modifiers, autobackpressure regulator pressure, column temperature, and the flow rate of mobile solvents, were optimized. The herbicide residues of napropamide, alachlor, quizalofop-ethyl, diphenamid, metolachlor, and clomazone in tobacco samples were successfully separated and detected at levels as low as 0.0043-0.0086 mg/kg within 5 min using a nonpolar high strength silica C18 selectivity for bases column and methanol as the cosolvent of the mobile phase of carbon dioxide (75-99.9%, v/v). Analysis of tobacco samples had recoveries of 69.8-95.0%, limit of quantitation of 0.