title: Simultaneous analysis of flunixin, naproxen, ethacrynic acid, indomethacin, phenylbutazone, mefenamic acid and thiosalicylic acid in plasma and urine by high-performance liquid chromatography and gas chromatography-mass spectrometry.
abstract: Simple and reproducible high-performance liquid chromatographic (HPLC) and gas chromatographic-mass spectrometric (GC-MS) methods have been developed for the simultaneous analysis of several acidic drugs in horse plasma and urine. Although the capillary GC-MS column provided better separation of the drugs than the reversed-phase C8 (3 microns, 75 mm) HPLC column, the total analysis time with HPLC was shorter than the total analysis time with GC-MS. The HPLC system equipped with a diode-array detector provided simultaneous screening (limit of detection 100-500 ng/ml) and confirmation (limit 1.0 micrograms/ml) of the drugs. The HPLC system equipped with fixed-wavelength ultraviolet and fluorescence detectors provided a relatively sensitive screening [limit of detection 50-150 ng/ml for ultraviolet and 10 ng/ml for fluorescence (naproxen only) detectors] of the drugs. However, the positive samples had to be confirmed by using either the diode-array detector or the GC-MS system. The GC-MS system provided simultaneous screening and confirmation of the drugs at very low concentrations (20-50 ng/ml).
authors.affiliation: Department of Veterinary Diagnostic Investigation, College of Veterinary Medicine, University of Minnesota, St. Paul 55108.
authors.forename: A K
authors.initials: AK
authors.lastname: Singh
authors.forename: Y
authors.initials: Y
authors.lastname: Jang
authors.forename: U
authors.initials: U
authors.lastname: Mishra
authors.forename: K
authors.initials: K
authors.lastname: Granley
mesh_terms: D000700:Analgesics / Q000097:blood* / Q000652:urine; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000097:blood* / Q000652:urine*; D001565:Benzoates / Q000097:blood / Q000652:urine; D002851:Chromatography, High Pressure Liquid; D003002:Clonixin / Q000031:analogs & derivatives / Q000097:blood / Q000652:urine; D004976:Ethacrynic Acid / Q000097:blood / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry; D006736:Horses; D007213:Indomethacin / Q000097:blood / Q000652:urine; D008528:Mefenamic Acid / Q000097:blood / Q000652:urine; D009288:Naproxen / Q000097:blood / Q000652:urine; D010653:Phenylbutazone / Q000097:blood / Q000652:urine; D013056:Spectrophotometry, Ultraviolet; D013438:Sulfhydryl Compounds; D013849:Thimerosal
chemical_list: D000700:Analgesics; D000894:Anti-Inflammatory Agents, Non-Steroidal; D001565:Benzoates; D013438:Sulfhydryl Compounds; C026196:2-thiosalicylic acid; D013849:Thimerosal; C014557:flunixin; D008528:Mefenamic Acid; D009288:Naproxen; D010653:Phenylbutazone; D004976:Ethacrynic Acid; D003002:Clonixin; D007213:Indomethacin