Recent progress in flow injection on-line separation and preconcentration techniques for electrothermal atomic absorption spectrometry (ETAAS) are reviewed, stressing the advancements made within the past 2 or 3years. Important trends and potentials for future development are discussed, including the use of air-transport and air-segmentation in on-line separation systems, the use of knotted reactors as a sorption medium, and other designs for on-line coprecipitation and solvent extraction systems to improve the robustness and efficiency of on-line separation systems for ETAAS.