An efficient and simple deep eutectic solvent (DES)-based liquid phase microextraction method has been used for chromotrope 2R dyestuff at trace levels prior to its UV-Vis spectropthometric determination. In this aspect, DES was prepared by decanoic acid and tetra-n-butylammonium bromide component used as 1:3 molar ratios. The developed separation-preconcentration method was optimised various analytical parameters such as pH, sample volume, eluent sample volume, volume of DES, sample volume of tetrahydrofuran (THF) and matrix effect etc. on the recovery of chromotrope 2R dyestuff were investigated. Quantitative recovery data for chromotrope 2R were found at pH 3.0. The detection limits of the chromotrope 2R were found to be as 5.4 mu g L-1. The accuracy of the developed method was successfully applied by the determination of the addition-recovery studies in the water sample, detergent and food samples with satisfactory results. The proposed method was applied to natural water samples for the determination of chromotrope 2R with satisfactory results.