title: Determination of oxytetracycline in salmon by liquid chromatography with metal-chelate fluorescence detection.
abstract: A liquid chromatography (LC) method is described for the determination of oxytetracycline (OTC) in farmed Atlantic salmon muscle tissue. The method involves homogenization of salmon tissue, extraction of OTC into Mcllvaine-EDTA buffer, acid precipitation of proteins, cleanup through tandem solid-phase extraction cartridges (Strata-X and aminopropyl), elution with mobile phase containing slightly alkaline buffer and Mg2+, and LC separation with metal-chelate induced fluorescence detection. Salmon tissue was fortified with 0.10, 0.25, 0.50, 0.75, and 1.0 microg/g (ppm) oxytetracycline. Average absolute recoveries were 84, 76, 70, 76, and 85%, respectively, with relative standard deviation (RSD) values all less than 9%. The interassay average recovery was 78%, with a 4.2% RSD. Determination was based on a standard graph using peak areas with standard solutions equivalent to 0.0625, 0.125, 0.25, 0.50, and 1.0 ppm in tissue. A set of 5 matrix controls (unfortified salmon tissue) were also analyzed, in which no OTC was detected. The lowest standard was used as the limit of quantitation.
authors.affiliation: U.S. Food and Drug Administration, Seafood Products Research Center/Pacific Regional Laboratory Northwest, 22201 23rd Dr SE, Bothell, WA 98021, USA. heidi.rupp@fda.gov
authors.forename: Heidi S
authors.initials: HS
authors.lastname: Rupp
authors.forename: Collin R
authors.initials: CR
authors.lastname: Anderson
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002138:Calibration; D002853:Chromatography, Liquid; D005456:Fluorescent Dyes; D007202:Indicators and Reagents; D008460:Meat / Q000032:analysis*; D018482:Muscle, Skeletal / Q000737:chemistry*; D010118:Oxytetracycline / Q000032:analysis*; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results; D012474:Salmon / Q000378:metabolism*; D012996:Solutions; D012997:Solvents; D013050:Spectrometry, Fluorescence
chemical_list: D000900:Anti-Bacterial Agents; D005456:Fluorescent Dyes; D007202:Indicators and Reagents; D012996:Solutions; D012997:Solvents; D010118:Oxytetracycline