Electromagnetic dispersive solid‐phase extraction based on polyaniline‐coated magnetite/silica materials for the determination of Sudan red I in drinks

By replacing the permanent magnet with an electromagnet, traditional magnetic solid‐phase extraction was developed into electromagnetic dispersive solid‐phase extraction. A simple operation of power on and off can realize the separation of adsorbents from solutions easily. The improvement makes it possible for the automation of the determination of Sudan Red I by high‐performance liquid chromatography. After series of optimization, a trace amount of Sudan red I was well‐determined, and excellent linearity was achieved in the range of 0.005 to 1 mg/L with the correlation coefficient ( R 2 ) = 0.997. The limit of detection with a signal‐to‐noise ratio of 3 was found to be 0.001 mg/L. The spiked recoveries of Sudan red I for the samples ranged from 93.6 to 104.9%. Moreover, the adsorbent could be recycled at least ten times. The results show that the electromagnetic dispersive solid‐phase extraction combined with high‐performance liquid chromatography is a rapid, eco‐friendly, effective, and sensitive determination method with fascinating automation potential and high practical applicability.