using of ultrasonic assisted dispersive liquid–liquid microextraction based on deep eutectic solvent for simultaneous determination of illegal dyes sudan orange g and sudan red 7b followed by derivative uv-vis spectrophotometry

In this study, simultaneous preconcentration and determination of illegal dyes sudan orange g and sudan red 7b was performed using the method ultrasonic assisted dispersive liquid–liquid microextraction based on deep eutectic solvent with second derivative ultraviolet spectrophotometry. deep eutectic solvent was synthesized by mixing tbab (hba) and decanoic acid (hbd). under optimized conditions including 1:3 molar ratios for tbab and decanoic acid, ph 5.0, 10 minutes centrifugation, 200 µl des as the extraction solvent, 450 µl of thf as the disperser solvent, 3 minutes ultrasonication, and 5.26 % (w/v) of nacl, the relative standard deviations of intra-day (rsd, n=3) were found 3.5 and 5 % for sog and sr7b, respectively. also, the rsd of inter-day were 10.5 and 9 % for sog and sr7b, respectively. the limit of detection for sog and sr7b were obtained as 0.014 and 0.011 μg ml-1. a good linearity range (r2 > 0.991) was obtained in the range of 0.036 – 0.900 and 0.030 -1.000 μg ml-1 for sog and sr7b, respectively. the preconcentration factor for both dyes were calculated 60 for all experiments. the effects of interfering ions and dyes were investigated. finally, the applicability of the method was applied for different real samples, including in chili powder, lipstick, river water and also in well water that relative recovery percentage of 88 to 114 was obtained for these samples.