title: Determination of bile acids by hollow fibre liquid-phase microextraction coupled with gas chromatography.
abstract: A method based on hollow-fibre liquid phase microextraction combined with gas chromatography was developed for determination of specific bile acids in caecal materials of rats. Nine unconjugated bile acids, including the primary bile acids (cholic acid, chenodeoxycholic acid and α-muricholic acid) and the secondary bile acids (lithocholic acid, deoxycholic acid, ursodeoxycholic acid, hyodeoxycholic acid, β-muricholic acid and ω-muricholic acid) were quantified. Extraction conditions were evaluated, including: sample pH, type of organic solvent and amount of caecal material to be extracted. To compensate for sample matrix effects during extraction the method of standard addition was applied. The satisfactory linearity (r(2)>0.9840), high recovery (84.2-108.7%) and good intra-assay (6.3-10.6%) and inter-assay (6.9-11.1%) precision illustrated the good performance of the present method. The method is rapid, simple and capable of detecting and determining bile acids with limit of detection (LOD) ranged from 0.002 to 0.067μg/mL and limits of quantification (LOQ) varied from 0.006 to 0.224μg/mL. The results indicated that the concentration of some secondary bile acids, which usually are associated with health problems, were lower in rats fed with fermentable dietary fibre compared with a fibre free control diet, while the concentration of primary bile acids, usually connected with positive health effects, were higher in rats fed with diets containing dietary fibre. Of the dietary fibres, guar gum and to some extent the mixture of pectin+guar gum had the most positive effects. Thus, it was concluded that the composition of bile acids can be affected by the type of diet.
authors.affiliation: Applied Nutrition and Food Chemistry, Department of Food Technology, Engineering and Nutrition, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden. Electronic address: Tannaz.Ghaffarzadegan@appliednutrition.lth.se.
authors.forename: T
authors.initials: T
authors.lastname: Ghaffarzadegan
authors.affiliation: Applied Nutrition and Food Chemistry, Department of Food Technology, Engineering and Nutrition, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Nyman
authors.affiliation: Centre for Analysis and Synthesis, Department of Chemistry, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden.
authors.forename: J Å
authors.initials: JÅ
authors.lastname: Jönsson
authors.affiliation: Centre for Analysis and Synthesis, Department of Chemistry, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Sandahl
mesh_terms: D000818:Animals; D001647:Bile Acids and Salts / Q000032:analysis* / Q000737:chemistry; D002432:Cecum / Q000737:chemistry; D002849:Chromatography, Gas / Q000379:methods*; D004043:Dietary Fiber / Q000008:administration & dosage; D005685:Galactans / Q000008:administration & dosage; D057230:Limit of Detection; D016014:Linear Models; D059627:Liquid Phase Microextraction / Q000379:methods*; D008351:Mannans / Q000008:administration & dosage; D010368:Pectins / Q000008:administration & dosage; D053149:Plant Gums / Q000008:administration & dosage; D051381:Rats; D015203:Reproducibility of Results
chemical_list: D001647:Bile Acids and Salts; D004043:Dietary Fiber; D005685:Galactans; D008351:Mannans; D053149:Plant Gums; D010368:Pectins; C007894:guar gum
keywords: Bile acids; Caecum; Gas chromatography; Hollow fibre liquid-phase microextraction