3.2. Determination of oligosaccharide profile by LC–MS
The desalted enzymatic hydrolysate was then analysed by LC–MS. The total ion current chromatogram and extracted ion current chromatogram of LC–MS are shown in Fig. 1. The deduced composition of oligosaccharides in the enzymatic hydrolysate and their calculated distribution coefficients are listed in Table 1. Eight oligosaccharides were detected by LC–MS. There was only a single oligosaccharide for each degree of polymerisation, and the ion current intensities of trisaccharide and tetrasaccharide were significantly higher than the others. Compared with the complex pattern following mild acid hydrolysis of A. Molpadioides SC-FUC
(data not shown), the oligosaccharide profile of the enzymatic hydrolysate was much simpler. Moreover, distribution coefficients of the enzymatically prepared oligosaccharides were significantly different from each other, suggesting that those oligosaccharides could be effectively separated employing SEC. These evidences all reflected the advantage of enzymatic preparation.