Abstract：ObjectiveTo establish an HPLC method for content determination of konjac glucomannan (KGM)in konjac refined powder,and compare with results of colorimetric assay.MethodsKGM was hydrolyzed with H2SO4(2.5 mol/L) at 110℃for 2 hours,which reacted with 1-phenyl-3-methyl-5-pyrazolone (PMP)before HPLC separation and formed two monosaccharides,D-mannose and D-glucose.HPLC was performed on the column of TOSOH TSK-GEL ODS with gradient elution of mobile phase A (acetonitrile)and mobile phase B (0.45 g potassium dihydrogen phosphate,0.5 ml TEA,100 ml acetonitrile,900 ml water,pH=7.5).The flow rate was 1.0 ml/min,detection wavelength was 250 nm,and column temperature was 30℃.Colorimetric method was tested with reference to GB/T18104-2000.ResultsLinearity of D-mannose was good in range of 21.2-159.3 μg(r=0.9998);while D-glucose in range of 21.5-154.2 μg (r=0.9999).The average recovery of KGM was 98.9% (RSD 2.2%).The contents were less 5%-7%than that by colorimetry.ConclusionHPLC method is more accurate than colorimetry to determine content of KGM in konjac refined powder,and would be better for quality control and grading of konjac refined powder.
Li WY，Li P，Li XQ，et al.Simultaneous quatification of uronic acid，amino sugar，and neutral sugar in the acidic polysaccharides extracterd from the roots of Angelica sinensis（Oliv.）Diels by HPLC[J].Food Anal Meth，2015，8 （8）：2087-2093.
京公网安备 11010502046607号