State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Carbohydr Res. 2013 Jan 25;366:50-4. doi: 10.1016/j.carres.2012.11.005. Epub 2012 Nov 21.
Acid hydrolysis and subsequent quantification of glucosamine (GlcN) are widely used for chitosan quantification. Degradation of GlcN during chitosan hydrolysis was the main reason for the decrease of recovery, which made the method improper for the quantification of chitosan. Ten milligram of chitosan hydrolyzed with 10 mL mixed acid solution of HCl-H₃PO₄ (75:25 in molar ratio) showed the highest recovery, significantly higher than HCl hydrolysis. Further study revealed that the optimum conditions involved the hydrolysis with HCl-H₃PO₄ (4.5:1.5M) for 24 h at 110 °C. The hydrolysate was neutralized and derived with 9-fluorenylmethoxycarbonyl chloride (FMOC-Cl) before HPLC quantification. The optimum ratio of FMOC-Cl:GlcN was 53:1, with excess FMOC-Cl induced by the high ionic strength of the solution. This quantification procedure was then validated and proved to be specific, with good linearity, accuracy, and precision, making it well-suited for the determination of chitosan.
酸水解和随后对氨基葡萄糖（GlcN）的定量分析广泛用于壳聚糖的定量。在壳聚糖水解过程中 GlcN 的降解是回收率降低的主要原因，这使得该方法不适合壳聚糖的定量。用摩尔比为 75:25 的 HCl-H₃PO₄混合酸溶液（10mL）水解 10mg 壳聚糖显示出最高的回收率，明显高于 HCl 水解。进一步的研究表明，最佳条件是在 110°C 下用 HCl-H₃PO₄（4.5:1.5M）水解 24 小时。水解产物用 9-芴甲氧羰基氯（FMOC-Cl）中和衍生，然后进行 HPLC 定量分析。FMOC-Cl:GlcN 的最佳比例为 53:1，由于溶液的高离子强度，导致 FMOC-Cl 过量。该定量程序经过验证，证明具有特异性、良好的线性、准确性和精密度，非常适合壳聚糖的测定。
