title: Quantitative analysis of closantel and rafoxanide in bovine and ovine muscles by high-performance liquid chromatography with fluorescence detection.
abstract: An HPLC method with a fluorescence detector (HPLC-FLD) was described for the quantitative determination of closantel and rafoxanide in bovine and ovine muscles. A structural analog closely related to rafoxanide, viz., N-[4-(4-chlorophenoxy)phenyl]-2-hydroxy-3,5-diiodobenzamide, was synthesized as an internal standard. Bovine and ovine muscles were extracted with acetonitrile-acetone (60 + 40, v/v) followed by cleanup on mixed mode anionic exchange SPE cartridges. After evaporation and reconstitution with the mobile phase, the sample was analyzed by HPLC-FLD using internal standard calibration. The method was validated by using fortified bovine and ovine muscles at 15, 30, and 60 microg/kg. The accuracy and RSD were 70-110% and < or =10%, respectively.
authors.affiliation: Analytical and Advisory Services Division, Government Laboratory, 7/F Ho Man Tin Government Office, Ho Man Tin, Kowloon, Hong Kong Special Administrative Region, China.
authors.forename: Hoi-Sze
authors.initials: HS
authors.lastname: Yeung
authors.forename: Wing-Hong
authors.initials: WH
authors.lastname: Ching
authors.forename: Shirley Sau-Ling
authors.initials: SS
authors.lastname: Lai
authors.forename: Wai-On
authors.initials: WO
authors.lastname: Lee
authors.forename: Yiu-Tung
authors.initials: YT
authors.lastname: Wong
mesh_terms: D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005453:Fluorescence; D009132:Muscles / Q000737:chemistry*; D011888:Rafoxanide / Q000032:analysis*; D012458:Salicylanilides / Q000032:analysis*; D012756:Sheep
chemical_list: D012458:Salicylanilides; D011888:Rafoxanide; C023342:closantel