An automated salting-out assisted liquid-liquid microextraction approach using 1-octylamine: On-line separation of tetracycline in urine samples followed by HPLC-UV determination

An automated salting-out assisted liquid-liquid microextraction (SALLME) procedure based on a flow system was developed as new approach for pretreatment of complex sample matrix. In this procedure 1-octylamine was investigated as novel extractant for the SALLME. The procedure involved aspiration of the 1-octylamine am sample solution into a mixing chamber of a flow system followed by their air-bubble mixing resulting to isotropic solution formation. To provide phase separation a salting-out agent solution was added into the mixing chamber After phase separation, the micellar 1-octylamine phase containing analyte was mixed with methanol an transported to a HPLC-UV system. To demonstrate the efficiency of the suggested approach, the automate procedure was applied for the HPLC-UV determination of tetracycline as a proof-of-concept analyte in human urine samples. Under the optimal conditions, the detector response of the analytes was linear in the con centration ranges of 0.5-20 mg L-1. The limit of detection, calculated from a blank test based on 3 sigma, wa 0.17 mg L-1. The results demonstrate that the developed approach is highly cost-effective, simple and rapid.