Ion-pair high performance liquid chromatographic separation and determination of thiabendazole, diphenyl and o-phenylphenol in citrus fruits and banana.

Abstract

An ion-pair high performance liquid chromatographic method was described for the simultaneous determination of thiabendazole (TBZ), diphenyl (DP) and o-phenylphenol (OPP) in citrus fruits and for the high sensitive determination of TBZ in banana. The use of ion-pair reagents such as 1-laurylsulfate for TBZ enabled the separation of three fungicides from interfering peaks. The fungicides were chromatographed on a Finepack SIL C18 column with acetonitrile-methanol-water (40 : 25 : 35) mixture adjusted pH to 2.5 containing 0.01 M sodium 1-laurylsulfate as mobile phase. The three fungicides in citrus fruits were detected by fluorescence detector set at excitation (Ex) 285 nm and emission (Em) 325 nm, and TBZ in banana was detected at Ex 305 nm and Em 350 nm. The recoveries of TBZ, DP and OPP added to citrus fruits were 94.1-98.0%, 90.1-93.0%, 92.0-95.0%, respectively, and the recovery of TBZ added to banana was 92.1-94.3%. The detection limits of DP, OPP and TBZ in citrus fruits were 0.5, 0.1 and 0.1 mg/kg, respectively, and the detection limit of TBZ in banana was 0.005 mg/kg.