Polydopamine-Coated Magnetic Molecularly Imprinted Polymers as a Dispersive SPE Adsorbent for Selective Recognition and Enrichment of Basic Orange 2 in Food Matrixes With High-Performance Liquid Chromatography Analysis.

Abstract

Background: Basic orange 2, as an industrial dye, exhibits severe effects on human health and has been forbidden for use as a food additive in many countries. The practical use of a common pretreatment process for basic orange 2 in food might be limited owing to time-consuming, high consumption of solvents and weak selectivity. Therefore, the aim of this study was to validate a pretreatment technology for basic orange 2 based on simplicity, being rapid, good selectivity, high sensitivity, and inexpensiveness to ensure safety for people.

Objectives: To develop a strategy for the extraction and enrichment of basic orange 2 in food matrixes by the specific magnetic molecularly imprinted polymers (MIPs) prior to the determination by high-performance liquid chromatography (HPLC).

Methods: The polymers with basic orange 2 as the template were deposited on the surface of ferroferric oxide nanoparticles (Fe3O4@PDA MIPs) through the self-assembly of dopamine in the weak alkaline solution. The Fe3O4@PDA MIPs as a dispersed solid phase extraction (SPE) sorbent were used for extracting and detecting basic orange 2 using HPLC. Parameters influencing extracting efficiencies were optimized, including the mass of MIPs, pH value, time for ultrasonication, elution solvent, and volume.

Results: Under optimal experimental conditions, the detection linearity of basic orange 2 was in the range of 0.04-1.0 μg/mL with a correlation coefficient of 0.9991 and limit of detection (LOD) of 5.8 ng/mL. The recoveries from spiked samples were 73.3-90% with a RSD of 3.1-8.1% in food samples. Notably, the magnetic MIPs showed excellent reusability during three extraction procedures.

Conclusion: The Fe3O4@PDA MIPs prepared have great potential for purification and enrichment of basic orange 2 prior to its determination by HPLC in dried beancurd stick, yellowfish, chili powder, drinks, and wine.

Highlights: The magnetic MIPs developed show good adsorption performance for basic orange 2 with a very low detection and excellent reusability. The assay was applied to detect basic orange 2 in food samples successfully.