Switchable-Hydrophilicity Solvent Liquid-Liquid Microextraction Prior to Spectrophotometric Determination of Sudan I Dye in Spices

Sudan I was determined using a switchable-hydrophilicity solvent (SHS) followed by ultraviolet/visible spectrophotometric detection at 445.0 nm in a simple, fast, sensitive, and low-cost method. The optimum switchable-hydrophilicity solvent liquid-liquid microextraction (SHS-LLME) conditions were achieved with 600 µL of octylamine and 600 µL of 10.0 M sodium hydroxide in 20.0 mL of the sample. Limits of detection ranged from 0.009 to 0.021 µg mL⁻¹. The coefficients of determination (R²) of the calibration graphs were higher than 0.9983 and relative standard deviations were below 8.6%. Enrichment factors ranged between 5.29 and 12.89. The proposed method was applied to spices with recoveries (%RR) between 92.5% and 104.4%.