High Internal Phase Emulsion Polymeric Monolith Extraction Coupling with High-Performance Liquid Chromatography for the Determination of Para Red and Sudan Dyes in Chilli Samples

Polymerized high internal phase emulsion (polyHIPE) monoliths were synthesized by in situ polymerization of the continuous phase of a high internal phase emulsion (HIPE) in syringes and successfully applied as monolithic sorbents to extract Para Red and Sudan dyes in chilli samples. Several parameters affecting the extraction efficiency were investigated, including the type of desorption solvent, sample loading rate, sample volume, and pH. Under the optimized conditions, a method using a monolithic polyHIPE column combined with high-performance liquid chromatography (HPLC) was developed for the simultaneous extraction and sensitive determination of Para Red and Sudan dyes in chilli samples. The proposed method had good linearity, with correlation coefficients ( R 2 ) from 0.9985 to 0.9995 and low detection limits (LODs, S/N = 3) in the range 1.5–12 ng/mL for the five analytes. The mean recoveries were ranged from 82.6 to 114.3% with relative standard deviations (RSDs) lower than 4.2%.