title: An LC-ESI-MS method for the quantitative analysis of bile acids composition in fecal materials.
abstract: In this work, a liquid chromatography coupled with electrospray ionization mass spectrometry (LC-ESI-MS) method was developed and validated for quantification of bile acids in fecal materials. Co-eluting matrix impurities in fecal materials have been shown to greatly suppress the ionization of analytes in mass spectrometry, which is known as the matrix effect. To correct large quantitative errors caused by the matrix effect, we developed a scheme that combined the standard addition method with internal standard (SA-IS). The fecal sample pretreatment involved a single step of extraction with ethanol. Bile acids were separated using a Luna C(18) column (150 mm, 2 mm i.d., 5 µm) with gradient elution. The deprotonated analytes were detected in selective ion monitoring mode. Our results showed that, by using this method, the accuracy of quantification was significantly improved in comparison to the conventional internal standard method. The linearity, sensitivity, accuracy and precision of the method were within the range of 0.05-5 µmol/L. This SA-IS method was successfully applied to the analysis of bile acids in the samples collected from patients diagnosed with inflammatory bowel disease.
authors.affiliation: Department of Chemistry, Cleveland State University, Cleveland, OH 44115, USA.
authors.forename: Xiaohan
authors.initials: X
authors.lastname: Cai
authors.forename: Yiding
authors.initials: Y
authors.lastname: Liu
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhou
authors.forename: Udayakumar
authors.initials: U
authors.lastname: Navaneethan
authors.forename: Bo
authors.initials: B
authors.lastname: Shen
authors.forename: Baochuan
authors.initials: B
authors.lastname: Guo
mesh_terms: D001647:Bile Acids and Salts / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D002853:Chromatography, Liquid / Q000379:methods*; D039021:Colonic Pouches; D005243:Feces / Q000737:chemistry*; D006801:Humans; D016014:Linear Models; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D001647:Bile Acids and Salts