dispersive liquid-liquid microextraction with deep eutectic solvents for the extraction and measurement of phenazopyridine by spectrophotometry and hplc

Determining small amounts of drugs in biological fluids (plasma, blood serum, and urine) is one of the most important issues in the process of evaluating the effect of the drugs on the body. one of the most important steps in this process is the pretreatment of the test samples. the dispersive liquid-liquid microextraction (dllme) technique is based on a ternary solvent system in which the first component contains an extractive organic solvent and the second one is a dispersing organic solvent that must be soluble in both aqueous and organic phases. the third component is a sample aqueous solution. the aim of this study is to obtain an efficient and reproducible method for preconcentration, extraction and measurement of phenazopyridine in biological samples of drug consumers [4]. another goal of this research is the synthesis and use of green, simple and fast deep eutectic solvents as disperser in the dllme method. in this study, a dllme technique was designed for the extraction of phenazopyridine in urine. a mixture of tbabr salt and ethylene glycol with specific molar ratio were used to prepare the deep eutectic solvent to be used as the disperser [1], [3]. undecanol was also used as the extraction solvent. recoveries of 95%-98% were obtained for urinary phenazopyridine extraction by the designed method. a preconcentration factor of 32.6 and an rsd of about 5% were achieved. the proposed method is fast, low cost and environmentally friendly [2].