[Simultaneous determination of four azo dyes in paprika powder by high performance liquid chromatography using a...

In this study, a solid-phase extraction-high performance liquid chromatography (SPE-HPLC) method was developed for the determination of Para Red, Orange Ⅱ sodium salt, Sudan Ⅰ, and Sudan Ⅱ in paprika powder based on a self-made porous aromatic framework-6 (PAF-6) solid-phase extraction cartridge. The major factors affecting the extraction efficiency and adsorption capacity of this solid-phase extraction were evaluated. Under optimized conditions, the limits of detection (LODs) and limits of quantification (LOQs) of the four target analytes ranged from 1.5 to 7.0 μg/L and 5.0 to 22.1 μg/L, respectively. The recoveries were in the range of 76.5-89.8%, and the relative standard deviation (RSD) was not more than 5.3% (n=6). Moreover, quantum chemistry calculations were performed to investigate the molecular interaction mechanism between the PAF-6 and target analytes. The results indicated that the target molecules could be stably adsorbed onto the PAF-6. The method is accurate, reliable, and sensitive, and can be successfully applied to detect the four azo dyes in paprika powder.