Thin layer chromatographic determination of citrinin.

A thin layer chromatographic (TLC) method is described for the determination of citrinin in feeds. Citrinin is extracted from feed with methanol and water, the mixture is made alkaline with 10% sodium carbonate, and the aqueous solution is filtered and extracted with chloroform to remove most of the interfering materials. The aqueous layer is acidified with 2N HCl and extracted with chloroform. The chloroform extract is concentrated and spotted on a thin layer chromatographic (TLC) plate which is developed in chloroform-acetone-ethanol-water (60 + 40 + 10 + 1). The citrinin is viewed under ultraviolet light after TLC. Either visual or fluorodensitometric quantitation is used. Recoveries of citrinin from various feed samples spiked at levels of 2.0--5 micrograms/g were 75--92%. The proposed method can detect 0.5 micrograms/g feed, including corn, silage, ready mixed feeds, and feed pellets.