333-41-5 Diazinon

Diazinon SOW was applied by air blast sprayers in accordance with typical application practices for orchards. Application began in March and continued until early-to mid-July. Dormant sprays typically contained diazinon in an oil mixture. Aqueous emulsions were applied as foliar sprays thereafter. Eqmpment was calibrated to provide an application rate of 3.4 kg active ingredient (a.i.)ha At least five applications were made at approximately 2-week intervals. During these applications, 233 samples were taken from spray tanks across the four treatment fields to estimate the application rate in PA, and 244 samples were collected in WA. 

Each vegefafion, soil or tissue sample was uniquely numbered and stored individually in a plastic Ziploc bag. Samples were frozen until shipped to laboratory facilities. Samples were shipped in coolers with dry-ice and were returned to freezers immediately upon receipt at the analytical laboratories. Control samples were stored separately from treated samples. 

Each sample was fortified with chlorpyrifos, as a reference standard, to determine the recovery during each extraction. Three portions of solvent were used, and the combined extract for each sample was dried with sodium sulfate. Analyses employed gas chromatography/flame photometric detection. Limits of detection for vegetation and animal tissues were 0.2 and 0.007 pg respectively. Recoveries from fortified samples were 82%. Diazoxon occurrence was infrequenf and at trace concentrations. 

Therefore, the data presented and discussed below address only diazinon. 

Application DPA N Geometric mean Residues Confidence limit (95%) Low High  

Diazinon, an organophosphoras compound with an anticholinesterase mode of action, was released for experimental evaluation in the early 1950s. Diazinon is now used extensively hy commercial and home applicators in a variety of formulations to control flies, cockroaches, lice on sheep, insect pests of ornamental plants and food crops (especially com, rice, onions, and sweet potatoes), forage crops such as alfalfa, and nematodes and soil insects in turf, lawns, and croplands. Diazinon is the most widely used organophosphorus pesticide in Pakistan to control cabbage root fly and carrot fly. In 1992, more than 612,000 kg of diazinon were used in California on alfalfa, nuts, stone fmits, vegetables, and other crops. 

Eisler, R. 1986. Diazinon hazards to fish, wildlife, and invertebrates a synoptic review. U.S. Fish Wildl. Serv. Biol. Rep. 85(1.9), 37 pp. 

Eisler, R. 2000. Diazinon. Pages 961-982 in Handbook of Chemical Risk Assessment Health Hazards to Humans, Plants, and Animals. Volume 2, Organics. Lewis Publishers, Boca Raton, Rorida. 

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Compounds with organophosphate moieties, such as Diazinon, Methyl Parathion, Coumaphos and Glyphosate are usually hydrolyzed at the phosphoms atom (40,58). Indeed several Flavobacterium isolates are able to grow using parathion and diazinon as sole sources of carbon. 

Chlorfenvinphos, cythion, diazinon, elsan, fenitrothion, fenthion, malathion, methyl parathion, mevinphos, monocrotophos, parathion, quinalphos, temephos, TEPA, tetrachlorvinphos... 

Diaminotoluene, 50 Dianisidine, 50 Diatomaceous earth, 50 Diazepam, 50 Diazinon, 50... 

DIAZINON AG 600 WBC , diazinon, 50 DIAZOL , diazinon, 50 Diazomethane, 50 Dibenz(a,h)anthracene, 50 Dibenzofuran, 51 DIBK, 51 Diborane, 51 DIBROM , naled, 51 Dibromobenzene, 51 Dibromochloromethane, 51... 

Figure 15.13 Comprehensive two-dimensional GC chromatogram of a supercritical fluid exti act of spiked human semm. Peak identification is as follows 1, dicamha 2, tiifluralin 3, dicliloran 4, phorate 5, pentachlorophenol 6, atrazine 7, fonofos 8, diazinon 9, cWorothalonil 10, terhufos 11, alachlor 12, matalaxyl 13, malathion 14, metalochlor 15, DCPA 16, captan 17, folpet 18, heptadecanoic acid. Adapted imm Analytical Chemistry, 66, Z. Liu et al., Comprehensive two-dimensional gas chromatography for the fast separation and determination of pesticides exuacted from human senim , pp. 3086-3092, copyright 1994, with pemiission from the American Chemical Society.

Dichlorovos, phorate, dimethoate, diazinon, disulfoton, methyl-parathion, malathion, parathion, azinphos-methyl, azinphos-ethyl, and so on... 

Azinphos ethyl (h/ f 20-25), malathion (h/ f 40-45) and diazinone (h/ f 47-52) yielded white chromatogram zones on a blue background immediately. Before in situ quantitation the chromatogram was dried in the air until no film of moisture could be seen on the layer surface. It was then dried completely in a stream of warm air whereby the blue coloration of the background changed to brown (Fig. 1). The visual detection limits were 200 ng substance per chromatogram zone. 

Fig. 1 chromatogram of the thiophosphate insecticides (each ca. SOO ng) after treatment with dipping solutions I and II (A) before and (B) after complete drying of the TLC plate. TVacks 1 and S mixture Track 2 azinphos ethyl Track 3 malathion Track 4 diazinone. 

Fig. 2 Reflectance scan of a chromatogram track with 500 ng azinphos ethyl (1), 580 ng malathion (2) and 590 ng diazinone (3) per chromatogram zone.

Diazinon Acute oral LD50 Rat 450 Birds (mean 4 species) 4.5 100... 

The organophosphorons insecticides dimethoate and diazinon are mnch more toxic to insects (e.g., housefly) than they are to the rat or other mammals. A major factor responsible for this is rapid detoxication of the active oxon forms of these insecticides by A-esterases of mammals. Insects in general appear to have no A-esterase activity or, at best, low A-esterase activity (some earlier stndies confnsed A-esterase activity with B-esterase activity) (Walker 1994b). Diazinon also shows marked selectivity between birds and mammals, which has been explained on the gronnds of rapid detoxication by A-esterase in mammals, an activity that is absent from the blood of most species of birds (see Section 23.23). The related OP insecticides pirimiphos methyl and pirimiphos ethyl show similar selectivity between birds and mammals. Pyrethroid insecticides are highly selective between insects and mammals, and this has been attributed to faster metabolic detoxication by mammals and greater sensitivity of target (Na+ channel) in insects. 

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