Simultaneous Determination of Febantel, Fenbendazole, Oxfendazole and Oxfendazole Sulfone in Livestock by Matrix Solid Phase Dispersion Extraction Technique and HPLC

SHU-CHU SU*, HSIAO-HUI CHOU, PI-CHIOU CHANG, CHAO-HONG LIU AND SHIN-SHOU CHOU

Bureau of Food and Drug Analysis, Department of Health, Executive Yuan 161-2 Kunyang St., Nangang District, Taipei City 115, Taiwan, R.O.C.

(Received: March 23, 2004; Accepted: May 31, 2004)

ABSTRACT

  Febantel, fenbendazole, oxfendazole and oxfendazole sulfone in livestock products were simultaneously extracted by traditional and matrix solid phase dispersion (MSPD) method, and then analyzed by high performance liquid chromatography (HPLC). In the traditional method, four benzimidazoles were extracted with acetonitrile under basic conditions, partitioned with n-hexane, and cleaned by a Sep-Pak C18 cartridge. In the MSPD method, samples were blended with Bondesil-C18, and the mixture was packed in a filtration column. This column was connected in tandem with an alumina N cartridge and eluted with acetonitrile. These benzimidazoles were determined by HPLC with a photodiode array detector. Recovery tests of benzimidazoles by these two  methods were performed at three spike levels. In the traditional method, febantel was found to be unstable during the sample preparation. Average recoveries of febantel ranged from 72.3 to 81.6%. Average recoveries at low concentration (0.04 ppm) of fenbendazole ranged from 75.0 to 88.3%, while the remaining benzimidazoles ranged from 80.3 to 108.7%. The coefficients of variation of intra-day and inter-day assays were lower than 6.95 and 12.12%, respectively. Average recoveries of the MSPD method ranged from 80.2 to 109.6%. The coefficients of
variation of intra-day and inter-day assays were lower than 4.47 and 7.89%, respectively. The detection limits for benzimidazoles were 0.010~0.020 ppm for the traditional method and 0.025~0.050 ppm for the MSPD method. The MSPD method minimized sample preparation time and solvents, and the analyte was stable during the analytical procedure with high recoveries. The MSPD method is suggested for use in routine analysis of benzimidazoles in livestock products.

Key words: febantel, fenbendazole, oxfendazole, matrix solid phase dispersion extraction (MSPD), high performance liquid chromatography (HPLC)