Abstract
Analysis of coumarone-indene resin (CI resin), a protective coating for citrus fruit, was examined. It was concise in the procedure and specific to the resin. The use of thin-layer chromatography with a mixed fluorescence substance resulted in that the spot of the resin was detected colorfully in accordance with its ultraviolet absorbing wave length. On the other hand, the double developing method using two kinds of developing solvents and diphenyl as a reference substance was successful in good seperation and making one spot for the resin.
In conclusion, the detective limit was 20ppm. CI resin was not detected in marketed grapefruit, orange and lemon imported from USA.
