2. Experimental
2.1. Materials
Furfural, levulinic acid (LA), 5-hydroxymethyl-2-furaldehyde
(HMF) and a-cellulose with an average particle size of 50 lm, were
supplied by Aladdin Reagent. Microcrystalline cellulose, HCl,
NaOH, NaCl, H2SO4, HNO3, Na2CO3, potassium ferricyanide and filter
paper were purchased from Sinopharm Chemical Reagent.
Glucose assay kits were obtained from Changchun Huili Biotech.
Co., Ltd. Absorbent cotton was purchased from Shanghai Dai Di
Medical Instrument Co., Ltd. and used as cotton fiber. Ramie fiber
was purified by alkali treatment of ramie bark after degumming.
Deionized water was used throughout the experiment