High-performance liquid chromatographic assay of lactic, pyruvic and acetic acids and lactic acid stereoisomers in calf feces, rumen fluid and urine.
To facilitate clinical investigation of metabolic acidosis, a high-performance liquid chromatographic method was adapted and validated for the chiral separation of D-(-) and L-(+)-lactic acid in calf feces, rumen fluid and urine. A non-chiral method was also adapted and validated for the separation of pyruvic, acetic and DL-(+/-)-lactic acids in calf feces and DL-(+/-)-lactic and pyruvic acids in rumen fluid. Separation and quantification were achieved using a reversed phase sulphonated polystyrenedivinylbenzene analytical column for pyruvic, acetic and racemic lactic acids and by a 3 microm octadecylsilane (ODS) packed analytical column coated with N,N-dioctyl-L-alanine as the chiral selector for the separation of lactic acid enantiomers with Cu(II)-containing eluents by stereoselective ligand exchange chromatography. Endogenous analytes were present in validation samples over a range of concentrations (0.2-14.8 mmol/l). For the stereoselective assay, mean intra-day accuracy ranged from 90.6 to 108.4% and intra-day precision from 0.3 to 13.8%. For the non-stereoselective assay, mean intra-day accuracy ranged from 90.4 to 108.8% and intra-day precision from 1.5 to 11.1%. The limit of quantitation was 1.0 mmol/l for D- and L-lactic acid, 0.06125 mmol/l for pyruvic acid, 1.0 mmol/l for DL-lactic acid and 1 mmol/l for acetic acid. These assays can be used to study the role of the gastrointestinal tract and kidney in metabolic acidosis.
Ewaschuk
Julia B
JB
College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5C9.
Naylor
Jonathan M
JM
Barabash
Wade A
WA
Zello
Gordon A
GA
D019342:Acetic Acid / Q000032:analysis* / Q000652:urine; D000818:Animals; D001826:Body Fluids / Q000737:chemistry*; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005243:Feces / Q000737:chemistry*; D019344:Lactic Acid / Q000032:analysis* / Q000652:urine; D019289:Pyruvic Acid / Q000032:analysis* / Q000652:urine; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism
D019344:Lactic Acid; D019289:Pyruvic Acid; D019342:Acetic Acid