海藻酸钠中金属元素的含量分析

针对如何测定海藻酸钠中金属元素的问题,建立了电感耦合等离子体质谱法(ICPMS)快速、灵敏、准确地同时测定不同来源海藻酸钠中10种金属元素含量的分析方法,并采用原子吸收光谱仪测定海藻酸钠中的钠元素含量。结果 10种金属元素的加样回收率为97.4%~102.3%(n=6),检测限为0.001~4.643ng/mL。钠金属元素的线性范围为0~3μg/mL(r=0.9970),线性关系良好。不同来源的海藻酸钠中11种金属元素含量均在规定限度内,但其含量大小有一定差别。通过比较6种不同来源、不同应用的海藻酸钠中所含有的金属元素含量,表明国外生产的海藻酸钠中的金属元素比国内的低。

Research and development of alginate-based raft forming system

Formulations of Gaviscon based on novel alginate raft forming system have been developed to prevent gastroesophageal reflux disease（GERD） symptoms. Alginate gel becomes buoyant and CO2-aerated as soon as Gaviscon comes into contact with gastric contents. This system can be characterized by several indicators, such as strength or coherence, volume, buoyancy, reflux resistance and resilience. In addition, the strength of the raft is influenced by many factors, such as molecular weight and the ratio of D-mannuronic and L-guluronic acid residues（M/G）, which are intrinsic factors in this formulation. Besides, there are several extrinsic factors, such as the presence of specific cations, the amount of carbon dioxide generated and entrapped in the raft. This review focused on how to evaluate the raft, introduced some factors that impact the raft and summarized the degradation of alginate and future advance.

海藻酸钠中糖醛酸含量测定方法的研究

目的利用硫酸咔唑法测定海藻酸钠中的糖醛酸的含量,并对该方法计算得出的结果进行校正。方法糖醛酸与硫酸咔唑试剂发生颜色反应,反应液在524 nm处有最大吸收,朗博比尔定律计算得出海藻酸钠中所有糖醛酸的含量,利用圆二色光谱法测定得出甘露糖醛酸与古罗糖醛酸含量之比(M/G值),根据M/G值以及糖醛酸的表观吸收系数计算得出每一种糖醛酸的含量,即海藻酸钠中甘露糖醛酸和古罗糖醛酸的含量。结果葡萄糖醛酸、半乳糖醛酸、艾杜糖醛酸、甘露糖醛酸和古罗糖醛酸5种糖醛酸的反应液在524 nm波长处有最大吸收,但吸收强度不同;通过朗博比尔定律计算得出5种糖醛酸的表征吸收系数分别为9 800 L/(mol·cm)、6 200 L/(mol·cm)、3 800 L/(mol·cm)、7 800 L/(mol·cm)和8 400 L/(mol·cm)。结论不同糖醛酸的吸收强度不同,海藻酸钠中含有2种不同的糖醛酸—甘露糖醛酸和古罗糖醛酸;不同褐藻中,甘露糖醛酸和古罗糖醛酸的含量也不同,可以通过2种糖醛酸所占比值及表观吸收系数校正含量测定结果。