Cloud point extraction of salicylic acid from human urine and its spectrofluorimetric determination

Salicylic acid (SA) has been extracted from human urine using cloud point extraction and determined applying spectrofluorimetry. Experimental conditions, such as concentrations of HCl and Triton X-114, temperature, and equilibration time have been adjusted to optimize the extraction process and to obtain analytical characteristics of the method. Linearity was observed in the analyte's concentration range of 0.025-2.5 mg L-1. Detection limit of the method was 0.011 mg L-1. Relative standard deviation for 5 replicate determinations of SA at the 1.0 mg L-1 concentration level was 1.85%. Good recoveries in the range of 85-94% were obtained for the spiked samples. The method was applied to the determination of SA in human urine.