A monolith adsorbent of hyper-crosslinked polymer, graphene oxide composite chitosan cryogel for in-syringe solid phase extraction of furfural derivatives from cellulosic biomass hydrolysate

Abstract

A porous composite monolith adsorbent of hyper-crosslinked polymer, graphene oxide and chitosan cryogel was fabricated for the extraction of furfural and 5-hydroxymethyl-furfural from cellulosic biomass hydrolysate. The composite adsorption materials synergistically enhanced the adsorption of furfural compounds and the porous chitosan cryogel helped to entrap and prevent the loss of the adsorbent composite. The composite monolith adsorbent was in-situ fabricated in a needle hub assembled with a disposable syringe performing in-syringe solid phase extraction. The extracted furfural compounds were quantified by high performance liquid chromatography. The fabricated adsorbent was characterized and the extraction conditions were optimized to achieve the best extraction recovery. In the optimum condition, the developed analytical approach provided linear from 1.0 to 50 ng/L for furfural and 0.5 to 50 ng/L for 5-hydroxymethyl-furfural, with respective detection limits of 0.25 ng/L and 0.20 ng/L. The developed approach was employed for the determination of furfural and 5-hydroxymethyl-furfural extracted from biomass hydrolysate of empty palm fruit bunch cellulose with satisfactory relative recoveries from 90.6 to 101.6 % with the RSDs below 6 %. The developed composite monolith adsorbent is easy to prepare and the extraction format is convenient to use. The good stability of the composite monolith adsorbent enabled reusability for 20 extraction-desorption cycles.