A simple method of dispersive liquid-liquid microextraction-solidified floating organic drop (DLLME-SFO) prior to flame atomic absorption spectrometry was successfully used for separation and preconcentration of copper in human hair and tea samples. The proposed method is simple, low in cost, and of high precision. In this work, optimization of experimental parameters influencing the extraction such as type and volume of extraction and disperser solvent, pH, the amount of chelating agent and extraction time is normally carried out using a step-by-step approach, in which each factor is varied sequentially. The effect of the interfering ions on the analytes recovery was also investigated. The calibration graph was linear in the range of 5–200 ng mL−1 with detection limit of 3.4 ng mL−1. The relative standard deviation (RSD) was 0.7% (n = 10, C = 2 ng mL−1) and the enhacment factor was 28.
