Partition behaviors of oxytetracycline hydrochloride(OTC) in small molecule alcohol/salt binary aqueous two-phase system

Based on the aqueous two-phase system,a new method of using ethanol and n-propanol with sodium dihydrogen phosphate binary aqueous two-phase system for extracting of oxytetracycline hydrochloride(OTC) was set up.The influence factors on partition behaviors of oxytetracycline hydrochloride(OTC) were studied,including the system composition,type and amount of salts,the pH value,the extraction temperature,and standing time after centrifuge.The results showed that the binary aqueous two-phase system can be used to study the distribution of antibiotics.When the system was ethanol and n-propanol,NaH2PO4 concentration of 48%,the pH value was 4~5,temperature was 25 ℃,and standing 12 h,the partition coefficient of oxytetracycline hydrochloride(OTC) was 21.95,and extraction rate was 86.09%.