title: Determination of phenolic compounds derived from hydrolysable tannins in biological matrices by RP-HPLC.
abstract: An RP-HPLC method for the determination of four phenolic compounds: gallic acid (GA), pyrogallol (PY), resorcinol (RE) and ellagic acid (EA), derived from hydrolysable tannins is reported. Separation was achieved on a SunFire C18 (250 x 4.6 mm id, 5 microm) column at 40 degrees C with gradient elution. UV detection at 280 nm was applied. The developed method was validated in terms of linearity, accuracy and precision. Satisfactory repeatability and between day precision were noticed with RSD values lower than 3%. Recoveries from different biological samples ranged from 91.50 to 105.25%. The LODs were estimated as 1.70 mg/L for PY, 1.68 mg/L for GA, 1.52 mg/L for RE and 0.98 mg/L for EA with a 20 microL injection volume. The method was applied for the determination of these compounds in oak leaves and in ruminal fluid and urine samples taken from beef cattle fed with oak leaves. The proposed method could be used in ruminant nutrition studies to verify the effect that a diet rich in tannins have on ruminal fermentation and to determine the toxicity of these compounds.
authors.affiliation: Analytical Chemistry, Department of Applied Chemistry and Physics, University of León, León, Spain.
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Díez
authors.forename: Pilar
authors.initials: P
authors.lastname: García del Moral
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Resines
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: Arín
mesh_terms: D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods; D004610:Ellagic Acid / Q000032:analysis* / Q000652:urine; D005707:Gallic Acid / Q000032:analysis* / Q000652:urine; D005766:Gastrointestinal Contents / Q000737:chemistry; D047348:Hydrolyzable Tannins / Q000737:chemistry* / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry; D011748:Pyrogallol / Q000032:analysis* / Q000652:urine; D029963:Quercus / Q000737:chemistry; D015203:Reproducibility of Results; D012118:Resorcinols / Q000032:analysis* / Q000652:urine; D012417:Rumen / Q000737:chemistry
chemical_list: D047348:Hydrolyzable Tannins; D012118:Resorcinols; D011748:Pyrogallol; D004610:Ellagic Acid; D005707:Gallic Acid; C031389:resorcinol