A simple and new reverse liquid-liquid microextraction for the automated spectrometric determination of doxycycline...

This work presents a new, simple and inexpensive reverse liquid-liquid microextraction of doxycycline (DOC) from chicken fat. In this just 13min extraction methodology, acidulated water, as extraction solvent (400µL), was used. A monochannel flow injection system was designed for the spectrometric determination of the analyte (ʎ=344nm). The extracted solution containing DOC was loaded into the injection valve of the continuous flow manifold. A lineal range between 100 and 700µgDOCkg^-1 sample was obtained. The LOD and LOQ were 33µgkg^-1 and 100µgkg^-1 respectively. The relative standard deviation was 4.87% and the sample throughput for the entire process was 4.5h^-1. As recovery values when the method was applied to real samples showed variability, the expanded uncertainties were calculated. Their values indicated that the new method is independent of the concentration of the analyte and the origin of the sample.