At present, the analytical methods of fructose mainly include enzymology, chemistry and chromatography. Enzymatic method has high sensitivity and specificity, but it is easy to be interfered by pollutants in the sample. At the same time, it is difficult to isolate and purify enzymes. Chemical methods can only determine the contents of total sugar and reducing sugar in the analysis of carbohydrates. Chromatography can separate oligosaccharides from each other and calculate them quantitatively. Usually, the chromatographic methods used for sugar analysis include gas chromatography, high performance liquid chromatography, liquid chromatography-mass spectrometry, capillary electrophoresis, ion chromatography, etc.

Ion chromatography separation combined with pulsed amperometric detection is an ideal method for sugar analysis. This method is based on the separation of sugar on anion exchange column after ionization in alkaline eluent. The method has strong anti-interference and high sensitivity.

The chromatogram is as follows:

Fig. 1 Ion chromatogram of fructan standard solution

Fig. 2 Ion Chromatography of a Milk Powder Sample