Deep eutectic solvents cross-linked molecularly imprinted chitosan microsphere for the micro-solid phase extraction of p-hydroxybenzoic acid from pear rind

A visual, rapid, and sensitive micro-solid phase extraction method was developed for the detection of p-hydroxybenzoic acid using molecularly imprinted chitosan microspheres based on deep eutectic solvents, both as a functional monomer and template. The parameters were optimized by using the response surface methodology strategy. The extraction capacity of p-hydroxybenzoic acid from pear rind under the optimized conditions using response surface methodology was 46.32 mg/g, when the pH of the extract solution (2), extraction time (35 min), extraction temperature (30 degrees C), and adsorbent dosage (2 mg). The molecularly imprinted chitosan microspheres produced higher selectivity and extraction capacity than the traditional materials.