title: Determination of Oxytetracycline from Salmon Muscle and Skin by Derivative Spectrophotometry.
abstract: A method was developed for the identification and quantification of oxytetracycline residues present in salmon muscle and skin using UV-Vis derivative spectrophotometry. With this method, it was possible to reduce the number of steps in the procedure typically required for instrumental analysis of a sample. The spectral variables, order of the derivative, scale factor, smoothing factor, and analytical wavelength were optimized using standard solutions of oxytetracycline dissolved in 900 mg/L oxalic acid in methanol. The matrix effect was significant; therefore, quantification for oxytetracycline residues was carried out using drug-free salmon muscle and skin samples fortified with oxytetracycline. The LOD and LOQ were found to be 271 and 903 μg/kg, respectively. The precision and accuracy of the method were validated using drug-free salmon muscle and skin tissues fortified at three different concentrations (8, 16, and 32 mg/kg) on 3 different days. The recoveries at all fortified concentrations were between 90 and 105%, and RSDs in all cases were less than 6.5%. This method can be used to screen out compliant samples and thereby reduce the number of suspect positive samples that will require further confirmatory analysis.
authors.affiliation: University of Chile, Faculty of Sciences, Department of Chemistry, PO Box 653, Santiago, Chile.
authors.forename: M Inés
authors.initials: MI
authors.lastname: Toral
authors.forename: Tamara
authors.initials: T
authors.lastname: Sabay
authors.forename: Sandra L
authors.initials: SL
authors.lastname: Orellana
authors.forename: Pablo
authors.initials: P
authors.lastname: Richter
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D004350:Drug Residues / Q000032:analysis; D005504:Food Analysis; D007202:Indicators and Reagents; D009132:Muscles / Q000737:chemistry*; D010118:Oxytetracycline / Q000032:analysis*; D015203:Reproducibility of Results; D012474:Salmon / Q000378:metabolism*; D012867:Skin / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000900:Anti-Bacterial Agents; D007202:Indicators and Reagents; D010118:Oxytetracycline