title: Determination of pharmaceutical compounds in animal feeds using high-performance liquid chromatography with refractive index detection.
abstract: Liquid chromatography with refractive index (RI) detection has been found to be very useful for the determination of pharmaceutical compounds in animal feeds. The RI detection can be especially valuable for the determination of compounds that have low ultraviolet-visible (UV-VIS) absorptions or absorb only at low UV wavelengths. The effect of the extraction solvent polarity, pH, and ion pairing reagents on feed extractables, as observed by RI and UV detection, has been studied. The RI detection typically shows less interference from the feed matrix than UV detection, particularly with polar extracting solvents. Changes in the extracting solvent pH do not significantly affect the response of feed extractables to RI or UV detection. With RI detection, analytes have been determined in feed at levels of 200 ppm with little or no cleanup.
authors.affiliation: Drug Development Department, CIBA-GEIGY Corporation, Suffern, NY.
authors.forename: Y
authors.initials: Y
authors.lastname: Golander
authors.forename: U
authors.initials: U
authors.lastname: Schurrath
authors.forename: J R
authors.initials: JR
authors.lastname: Luch
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D006863:Hydrogen-Ion Concentration; D004364:Pharmaceutical Preparations / Q000032:analysis*; D012031:Refractometry; D013056:Spectrophotometry, Ultraviolet; D014580:Ursodeoxycholic Acid / Q000032:analysis
chemical_list: D004364:Pharmaceutical Preparations; D014580:Ursodeoxycholic Acid