采用化学动力学方法,对市售海藻酸钠(NaAl)及其精制品溶液的粘度稳定性进行了研究和比较。结果表明:NaAl溶液粘度下降符合一级反应动力学;这些样品粘度下降半衰期为8～15年(20℃),精制品粘度稳定性通常优于粗制商品。用“一点法”测定NaAl的特性粘数。结果与中国药典法比较,偏差小于1%,具有简便、快速、准确的特点。还报道了NaAl中甘露糖醛酸与古洛糖醛酸的薄层分离条件。 The chemical stability of the commercially available sodium alginate (NaAl) and its refined solution was studied and compared using chemical kinetics. The results show that the decrease of viscosity of NaAl solution conforms to the first-order reaction kinetics. The half-life of viscosity decrease of these samples is 8 to 15 years (20 ℃). The viscosity stability of refined products is usually better than that of crude products. Use “one point method” to determine intrinsic viscosity of NaAl. The results compared with the Chinese Pharmacopoeia, the deviation of less than 1%, with a simple, rapid and accurate features. The separation conditions of mannuronic acid and guluronic acid in NaAl were also reported.