LAUSR

Abstract In this work, a rapid and effective analytical procedure has been developed for phenol determination from aqueous samples using a smartphone-based colorimetric system. This methodology is based on the reaction of the phenol with 4-aminoantipyrine (4-AAP) in the presence of the oxidant agent, forming of brown-orange color product which extractable by ultrasound assisted-dispersive liquid–liquid microextraction (UA-DLLME), and direct obtaining of RGB (Red, Green, and Blue) values of organic phase in a conic tube by free Android app Color Grab. The effect of various parameters on the derivatization process and microextraction procedure including; sample pH, hexacyanoferrate and 4-AAP concentration, type and volume of extraction solvent and ultrasound time were investigated. Under the optimized conditions, a working range between the 5.0 and 300 μg L−1 of phenol was attained and the limit of detection (LOD) and limit of quantification (LOQ) obtained were 1.7 and 5.7 μg L−1, respectively. Finally, the proposed methodology was applied for phenol determination in environmental water and wastewater samples with satisfactory results. The recoveries of phenol from spiked samples were found in the range of 93.7–103.6 %.