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Stereoselective liquid chromatographic determination of 1′‐oxobufuralol and 1′‐hydroxybufuralol in rat liver microsomal fraction using hollow‐fiber liquid‐phase microextraction for sample preparation
Author(s) -
Barth Thiago,
Simões Rodrigo A.,
Pupo Mônica T.,
Okano Laura T.,
Bonato Pierina S.
Publication year - 2011
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.201100464
Subject(s) - chromatography , chemistry , diethylamine , high performance liquid chromatography , detection limit , extraction (chemistry) , acetic acid , stereoselectivity , hexane , enantiomer , solvent , analytical chemistry (journal) , stereochemistry , organic chemistry , catalysis
A three‐phase hollow‐fiber liquid‐phase microextraction (HF‐LPME) method for the stereoselective determination of bufuralol metabolites 1′‐oxobufuralol (1′‐Oxo‐BF) and 1′‐hydroxybufuralol (1′‐OH‐BF) in microsomal preparations is described for the first time. The HPLC analysis was carried out using a Chiralcel OD‐H column with hexane/2‐propanol/methanol (97.5:2.0:0.5, v/v/v) plus 0.5% diethylamine as the mobile phase, and UV detection at 248 and 273 nm. The HF‐LPME optimized conditions involved: n ‐octanol as the organic solvent, 0.2 mol/L acetic acid as the acceptor phase, donor phase pH adjusted to 13, sample agitation at 1500 rpm and extraction for 30 min. By using this extraction procedure, the recovery rates were in the range of 63–69%. The method was linear over the concentration range of 100–5000 ng/mL for each enantiomer of 1′‐Oxo‐BF ( r >0.9978) and of 100–2500 ng/mL for each stereoisomer of 1′‐OH‐BF ( r >0.9957). The quantification limits were 100 ng/mL for all analytes. The validated method was used to assess the in vitro biotransformation of bufuralol using rat liver microsomal fraction that demonstrated predominant formation of ( S )‐1′‐Oxo‐BF and ( R , R )‐1′‐OH‐BF.