Biomaterial Database

Spectrophotometric determination of methomyl residues in selected vegetables, grains, and soil. 1977

J R Rangaswamy, and S R Prakash, and Y N Vijayashankar

Methomyl (S-methyl-N-[(methylcarbamoyl) oxy] thioacetimidate) is converted to oxime and hydroxylamine by alkali and acid treatment, respectively. Hydroxylamine is oxidized with iodine in the presence of sulfanilic acid to yield p-diazoniumbenzenesulfonic acid which is coupled with alpha-naphthylamine to form a crimson p-benzenesulfonic acid-azo-alpha-naphthylamine with an absorption maximum at 520 nm. The relationship between absorbance and concentration of methomyl is linear in the range 0.5-10 microgram. The method is sensitive and specific; 0.625 ppm methomyl can be determined in a 40 g sample of selected vegetables, grains, and soil.

UI	MeSH Term	Description	Entries
D007306	Insecticides	Pesticides designed to control insects that are harmful to man. The insects may be directly harmful, as those acting as disease vectors, or indirectly harmful, as destroyers of crops, food products, or textile fabrics.	Insecticide
D008724	Methomyl	A carbamate insecticide with anticholinesterase activity.	Lannate,Lannate 20
D010573	Pesticide Residues	Pesticides or their breakdown products remaining in the environment following their normal use or accidental contamination.	Pesticide Residue,Residue, Pesticide,Residues, Pesticide
D002523	Edible Grain	SEEDS used as a major nutritional source, most often the grain from the POACEAE family.	Cereals,Cereal Grain,Cereal,Cereal Grains,Edible Grains,Grain, Cereal,Grain, Edible,Grains, Cereal,Grains, Edible
D012987	Soil	The unconsolidated mineral or organic matter on the surface of the earth that serves as a natural medium for the growth of land plants.	Peat,Humus,Soils
D013053	Spectrophotometry	The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.
D014675	Vegetables	A food group comprised of EDIBLE PLANTS or their parts.	Vegetable