Sharma J P, Koritz G D, Perkins E G, Bevill R F
J Pharm Sci. 1977 Sep;66(9):1319-22. doi: 10.1002/jps.2600660929.
The quantitation of oxytetracycline, tetracycline, and chlortetracycline was accomplished by high-pressure liquid chromatography using an anion-exchange column. The tetracyclines were extracted from urine as their calcium complexes. Concentrations as low as 12 microgram of oxytetracycline/ml and 4 microgram of tetracycline and chlortetracycline/ml were quantitated accurately. The relative standard deviation of the method varied from 0 to 5%.