title: [The determination of konjac glucomannan in konjac refined powder and monosaccharide compositions by HPLC].
abstract: OBJECTIVE
  To establish a quantitative method for the content determination and monosaccharide composition analysis of Konjac glucomannan (KGM) in Konjac refined powder by pre-column derivatization high performance liquid chromatographic method (HPLC).
  
  
  METHODS
  The two derivatives combined reducing monosaccharides with 1-phenyl-3-methyl-5-pyrazolone (PMP) were separated by reverse-phase HPLC using a developed fragment gradient elution process, and monitored by ultraviolet detector at 250 nm. The broad reagent peak of PMP was separated very well from all the PMP-sugars, and good separation was achieved for derivatives of mannose and glucose. The quantitative methods of two reducing monosaccharides were studied by the method combined internal and external standard; while the KGM content in Konjac refined powder was determined.
  
  
  RESULTS
  Linearity of glucose was good (r = 0.9990) in range of 1.002-8.016 nmol; while mannose (r = 0.9994) in range of 1.001-8.008 nmol. The average recovery of this method was 98.1%, RSD of repeatability was 1.72%. KGM content in Konjac refined powder was 79.5%, ratio of glucose to mannose in KGM was 1:1.51.
  
  
  CONCLUSIONS
  This method is a sample, convenient and rapid method that can determine KGM content and analyze monosaccharide compositions in KGM, which will be helpful to quality assessment of Konjac refined powder.
authors.affiliation: Department of Clinical Examination, Jilin Military Medical College, Fourth Military Medical University, Jilin 132011, China. yuanzhonghai806@sohu.com
authors.forename: Zhong-hai
authors.initials: ZH
authors.lastname: Yuan
authors.forename: Dao-cheng
authors.initials: DC
authors.lastname: Wu
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Hong
authors.initials: H
authors.lastname: Wu
authors.forename: Xiao-ye
authors.initials: XY
authors.lastname: Li
mesh_terms: D031056:Amorphophallus / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D005947:Glucose / Q000737:chemistry; D008351:Mannans / Q000032:analysis* / Q000737:chemistry; D008358:Mannose / Q000737:chemistry; D009005:Monosaccharides / Q000032:analysis*; D010946:Plants, Medicinal / Q000737:chemistry*; D011208:Powders / Q000737:chemistry
chemical_list: D008351:Mannans; D009005:Monosaccharides; D011208:Powders; C022901:(1-6)-alpha-glucomannan; D005947:Glucose; D008358:Mannose