Barley, carboxin

Plant. In plants (barley, cotton and wheat) and water, carboxin oxidizes to the corresponding sulfoxide (Worthing and Hance, 1991). 

Farrow et al. [159] determined the systemic fungicide carboxin (2,3-dihy-dro-6-methyl-5-phenylcarbamoyl-l,4-oxathiin), which is used in barley and wheat seed treatment of cereals. 

The carboxin is extracted from the sample with acetone in a Soxhlet extraction apparatus and, after concentration of the extract, is determined via gas-liquid chromatography using a nitrogen-selective detector. The presence of carboxin is confirmed by the use of a sulfur flame photometric detector. Recoveries ranged from 73 to 80% (barley) and 73 to 78% (wheat). 

Carboxin was the first seed disinfection agent with systemic activity used in cereals to control loose smut in barley. Today, newer fungicides have displaced carboxin. 

---