Development of in-situ produced CO2 switchable fatty acid microextraction based solidification of floating organic droplet for quantification of morin and quercetin in tea, vegetable and fruit juice samples by HPLC

•An in-situ-CO2-SFA-ME-SFO was evaluated to quantify quercetin and morin.•A medium chain fatty acid was investigated as a switchable hydrophilicity solvent.•An In situ acid–based reaction generated carbon dioxide bubbles.•Solidification of the fatty acid provided separation without the specific equipment.•Morin and quercetin were determined in tea and fruit juice samples with good recovery.