Abstract: In this study,an accelerated solvent extraction(ASE)method was developed for extraction of polysaccharides in 16 alpine plants from Qinghai.A phenol-vitriolic colorimetry method was set up for determination of polysaccharides contents.The lipids were removed using ASE350 with diethyl ether through on-line purification. Monosaccharides,oligosaccharides and uronic acid were on-line removed with 75% aqueous ethanol,meanwhile the samples were bleached with it.The plant polysaccharides were continuously on-line extracted by distilled water through ASE.Colloidal substances that were formed by swelling of gelatinized starch were removed by centrifugation,proteins in the supernatant were removed with Sevag reagent.The 5% phenol solution and concentrated sulfuric acid were sequencely added in the test solutions for chromogenic reaction.The absorbance was monitored at 490 nm using distilled water as blank.Polysaccharide conversion factors were measured.The results indicated that the linear response range of polysaccharides in samples was 0.01~0.10 mg(r=0.9996).The average recovery(n=9)was 97.26% and RSD was 0.53%.The assay demonstrated that the method was simple,accurate,stable and reproducible.It was suitable for the determination of polysaccharides in plant samples.In addition,it can be used to assist the quality evaluation of alpine plants from Qinghai.

Key words: accelerated solvent extraction, on-line remove impurities and extract, phenol-vitriolic colorimetry method, alpine plants from Qinghai, polysaccharide, assay