Ethanol and acetone-ammonium sulfate binary aqueous two-phase extraction separation of tetracycline

Based on small molecule alcohol and organic molecule aqueous two-phase system,a new method was developed for extraction of tetracycline hydrochloride in ethanol-acetone-ammonium sulfate binary aqueous system.Several factors on the tetracycline hydrochloride allocation behavior was studied,including the type,amounts and relative proportions of salt-alcohol-small molecular organics,temperature,pH and the coexisting substances.The results showed that when ammonium sulfate was 41%,the volume ratio of absolute ethyl alcohol and acetone was 2 ∶1,and the solution pH was 4.5—5,the extraction rate and the distribution coefficient of tetracycline hydrochloride were 90% and 57 respectively.The relative error was ±7%,the ions including K+,Na+,F-,Cl-,NO-3,Br-,the hydrochloride metacycline,and other components in the system such as chloramphenicol penicillin,erythromycin,starch and sucrose,glucose and fructose have not any effect on the extraction behavior.