Electrochemically controlled solid phase microextraction based on nanostructured polypyrrole film for selective extraction of sunset yellow in food samples

Solid-phase microextraction (SPME) is extensively employed in analytical chemistry to improve extraction efficiency. The development of SMPE methods is still a great challenge thanks to its poor selectivity. Herein, we have reported the application of electrochemically controlled solid-phase microextraction (EC-SPME) based on a conducting molecularly imprinted polymer (CMIP) film for the selective extraction and determination of sunset yellow (SY) in food samples using a UV-Vis spectrophotometer. The CMIP film was electrochemically prepared in the presence of SY anions as the template anions during the electropolymerization of pyrrole onto the stainless steel fiber surface using the potentiostat method. The imprinting process was carefully investigated via FESEM, CV, and EIS approaches. In the developed EC-SPME method, the extraction of SY occurred at CMIP when the potential was applied, and as a consequence, the sensing performance was dramatically enhanced as compared to that obtained via SPME. The film template with SY showed high selectivity for SY compared to studied interferents. The EC-SPME method responded linearly to SY with a limit of detection of 0.34 mu mol L-1. Also, the developed method had a sufficient sensitivity level to determine analyte in food samples. Finally, the suitability of the proposed method for the analysis of orange-flavored jelly powder, peach juice powder, and beverage samples was demonstrated. To validate the proposed method, the results were compared with those obtained through HPLC-UV analysis.

Automated summary

A novel electrochemically controlled solid-phase microextraction (EC-SPME) method based on a conducting molecularly imprinted polymer (CMIP) film was developed for the selective extraction and determination of sunset yellow (SY) in food samples, demonstrating high sensitivity and selectivity compared to traditional SPME methods.