Herein, we show for the first time that an acidic deep eutectic solvent (DES) can be used to complete dissolution of layered double hydroxides (LDHs) as sorbents in the vortex assisted in-situ solid phase for extraction of doxepin and amitriptyline from urine and pharmaceutical formulation samples. Moreover, the ability of a basic and a neutral DES was investigated to dissolve the LDH sorbents. These solvents were synthesized by mixing choline chloride as a cheap and biodegradable hydrogen bond acceptor and a series of hydrogen bond donors, namely malonic acid, ethylene glycol and urea. The technique requires minimal sample preparation and eliminates the consumption of harmful organic solvent to dissolve the LDHs. Optimization was done by utilizing the Box-Behnken design. The calibration graphs have an excellent linearity in the concentration range of 1-400 μg/L for both analytes. The coefficients of determination (r2) and limits of detection (LODs) were 0.995-0.999 and 0.69-0.84 μg/L, respectively.Herein, we show for the first time that an acidic deep eutectic solvent (DES) can be used to complete dissolution of layered double hydroxides (LDHs) as sorbents in the vortex assistedin-situ solid phase for extraction of doxepin and amitriptyline from urine and pharmaceutical formulation samples. Moreover, the ability of a basic and a neutral DES was investigated to dissolve the LDH sorbents. These solvents were synthesized by mixing choline chloride as a cheap and biodegradable hydrogen bond acceptor and a series of hydrogen bond donors, namely malonic acid, ethylene glycol and urea. The technique requires minimal sample preparation and eliminates the consumption of harmful organic solvent to dissolve the LDHs. Optimization was done by utilizing the Box-Behnken design. The calibration graphs have an excellent linearity in the concentration range of 1-400 μg/L for both analytes. The coefficients of determination (r2) and limits of detection (LODs) were 0.995-0.999 and 0.69-0.84 μg/L, respectively.
