title: Separation and characterization of synthetic impurities of triclabendazole by reversed-phase high-performance liquid chromatography/electrospray ionization mass spectrometry.
abstract: A simple high-performance liquid chromatography/electrospray ionization mass spectrometry (HPLC/ESI-MS) method for the separation and characterization of impurities in the synthesis of triclabendazole has been developed. The analytical separation was achieved on a reversed-phase C18 column using acetonitrile and water (60:40, v/v) as mobile solvent at a flow-rate of 1.0 ml/min at 25 degrees C, and an UV detection at 230 nm. The on-line HPLC/ESI-MSn examinations were performed using ion trap analyzer with extraction ion chromatography (EIC) technique in positive or negative ion modes. The semi-preparative separation was performed with a reversed-phase column using methanol and water (75:25, v/v) as mobile solvent at a flow-rate of 4 ml/min at 25 degrees C, and an UV detection at 230 nm. Thus, two impurities were detected and identified as 5-chloro-6-(2,3,4-trichlorophenoxy)-2-methylsulfanyl-1H-benzoimidazole and 5-chloro-6-(2,3-dichlorophenoxy)-1-methyl-2-methylsulfanyl-1H-benzoimidazole. Meanwhile, some intermediates of impurity-1 in multi-step synthetic reactions, were tracked. Structural elucidation by 1D and 2D NMR and ESI-MSn was discussed.
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang Province 310027, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhou
authors.forename: Yuanpo
authors.initials: Y
authors.lastname: Tai
authors.forename: Cuirong
authors.initials: C
authors.lastname: Sun
authors.forename: Yuanjiang
authors.initials: Y
authors.lastname: Pan
mesh_terms: D001562:Benzimidazoles / Q000032:analysis* / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004340:Drug Contamination; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D000077682:Triclabendazole
chemical_list: D001562:Benzimidazoles; D000077682:Triclabendazole