Abstract
A method was developed for the separation and determination of three preservatives (fungicides), diphenyl (DP), o-phenylphenol (OPP) and thiabendazole (TB) in citrus fruits. The fruit was extracted with ethyl acetate, and the extract was concentrated. The solution, obtained by adding xylene to the concentrate and subsequently concentrating the mixture, was loaded on an alumina column (1.5×8 cm). After washing the column with hexane, DP was eluted with ethyl acetate and both OPP and TB with a mixture of aqueous ammonia and methanol (1 : 4). They were determined by submitting the fractions to gas-chromatography using two detectors, which were FID for the determination of DP and OPP and ECD for TB. Recoveries of DP (2 ppm), OPP (0.8 ppm), and TB (0.5 ppm) added to citrus fruits were 96.1, 95.4, and 93.7%, respectively. This method was successfully applied for the determination of three preservatives in lemons, oranges, and grapefruits.
