[Resorcinol-spectrophotometric method for the determination of fructose in mustard leaf's amylose].

A method using seliwanoff reaction is proposed for the determination of fructose in the amylose of mustard leaves. Fructose reacts with resorcinol forming a red compound with a maximum absorption at 473 nm. The calibration curve is linear over the range of 0-83 micrograms.mL-1 with a correlation coefficient of 0.9998. The content of fructose in the amylose of mustard leaves is found to be 11.41%. Quantitative analysis used for the fructose of syrup include such as volumetric analysis, then layer chromatography, polarimetry, high pressure liquid chromatography and spectrophotometric analysis. According to different color-developing agents, spectrophotometric analysis may be classified as carbazole method, ammonium molybdate way and resorcinol way etc. reported by foreign papers is hard to operate and colored complex is unstable.