Add time:09/09/2019         Source:sciencedirect.com

The gas-liquid chromatographic behaviour of methomyl (methyl N-[(methyl- carbamoyl)oxy]thiocetimidate), oxamyl (methyl N′,N′-dimethyl-N-[(methylcarba- moyl)oxy]-1-thiooxammidate), their respective oxime hydrlysis products and the trimethylsilyl (TMS) ethers of the oximes of 5% OV-1 was studied under isothermal conditions using a flame-photometric detector in the sulfur-selective mode. In contrast to the behavior of the parent carbamates and underivatized oximes, the oxime- TMS ethers readily produced symmetrical peaks of consistent size. Quantities of derivative equivalent to at least 0.25 ng of oxime were easily measurable. Derivative formation was reproducible for standards over t he range 10.0 to 0.25 μgl/ml in benzene and at 10.0 and 0.05 μg/ml in the presence of extractives from tomato, carrot ansd celery at concentrations equivalent to 10 g/ml of crop. Derivative yields from crop extract fotifications were 89% or better in most cases. Both the carbamates and oximes were simply and consistently recovered in high yield from crops fortified at 1.00 and 0.05 ppm using the procedures described. The inclusion of a second analytical step provided separate analysis for oximes and carbamates. The application of these observations of the analyses of residues in crops is discussed.

We also recommend Trading Suppliers and Manufacturers of METHOMYL-OXIME (cas 13749-94-5). Pls Click Website Link as below: cas 13749-94-5 suppliers