Construction of hydrophilic hypercrosslinked polymer based on natural kaempferol for highly effective extraction of 5-nitroimidazoles in environmental water, honey and fish samples

A series of novel hydroxyl-functional hypercrosslinked polymers (named as HCPs-Kae) were fabricated using natural and environmentally benign kaempferol as monomer via one-step Friedel-Crafts reaction. The prepared HCP-Kae1-24 h exhibited large surface area, good hydrophilicity and excellent adsorption performance to 5-nitroimidazoles (5-NDZs). Thus, by applying HCP-Kae1-24 h as a solid-phase extraction adsorbent, a sensitive method was developed for enrichment of 5-NDZs including metronidazole, ronidazole, secnidazole, dimetridazole and ornidazole prior to high performance liquid chromatography analysis. Under the optimum conditions, good linearities were achieved in the range of 0.10-100.0 ng mL(-1) for water, 1.3-500.0 ng g(-1) for honey, and 1.7-100.0 ng g(-1) for fish meat. The detection limits of the method were 0.03-0.05 ng mL(-1), 0.4-1.0 ng g(-1), 0.5-1.0 ng g(-1) for water, honey and fish meat, respectively. High method recovery was obtained in the range of 84-118% with relative standard deviations lower than 8.9%. The established method was successfully applied to the detection of 5-NDZs in environmental water, honey and fish samples. This work provides a new strategy for constructing hydroxyl-functional HCPs by using natural resource as robust adsorbent for adsorption/extraction applications.

Automated summary

In this study, a series of novel hydroxyl-functional hypercrosslinked polymers were prepared using natural and environmentally benign kaempferol. These polymers showed excellent adsorption performance to 5-nitroimidazoles (5-NDZs). By applying these polymers as solid-phase extraction adsorbents, a sensitive method was developed for the enrichment of 5-NDZs in water, honey and fish samples. The method showed good linearity, low detection limits, and high recovery rates.