Monitoring of oxytetracycline in ovine milk by high-performance liquid chromatography.
A method for 'in vivo' determination of the oxytetracyclin residues in ovine milk at low levels is described. Two groups of Sardinian breed sheep were treated with a dose of oxytetracycline by intramammary infusion and intramuscular administration, respectively. Oxytetracycline residues in extracts obtained from a preliminary cleanup procedure, were detected by an isocratic high-performance liquid chromatography (HPLC) method. Linear calibration plots were obtained over a large concentration range of 1 mg ml(-1)-10 ng ml(-1), with correlation coefficients higher than 0.996. Recoveries between 85.8 and 98.9% were obtained. Limit of detection (LOD) and limit of determination (LOQ) were 5.2 and 17.5 ng ml(-1), respectively. This method would be useful for routine monitoring of oxytetracycline residues in ovine dairy milk.
Boatto
G
G
Dipartimento Farmaco Chimico Tossicologico, Facoltà di Farmacia, Università degli Studi di Sassari, Italy. gboatto@ssmain.uniss.it
Pau
A
A
Palomba
M
M
Arenare
L
L
Cerri
R
R
D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000032:analysis* / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid; D004350:Drug Residues; D005260:Female; D007202:Indicators and Reagents; D007267:Injections; D007273:Injections, Intramuscular; D008321:Mammary Glands, Animal; D008892:Milk / Q000737:chemistry*; D010118:Oxytetracycline / Q000008:administration & dosage / Q000032:analysis* / Q000493:pharmacokinetics; D012756:Sheep
D000900:Anti-Bacterial Agents; D007202:Indicators and Reagents; D010118:Oxytetracycline