摘要
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。
Objective To determine the content of uronic acid in sodium alginate by carbazole sulfate,and to correct the results calculated by this method. Methods The reaction solution had the maximum absorption at 524 nm,and the Lambert’s law calculated the content of all uronic acid in sodium alginate. The M/G value was determined by circular dichroism spectroscopy.Based on the ratio of mannuronic acid to guluronic acid content（M/G） value and the apparent absorption coefficient of uronic acid,the content of each uronic acid was calculated,that is,the content of mannuronic acid and guluronic acid in sodium alginate. Results The reaction solution of glucuronic acid,galacturonic acid,iduronic acid,mannuronic acid and guluronic acid had the maximum absorption at a wavelength of 524 nm,and the absorption intensity was different. The absorption coefficients of five kinds of uronic acid were 9 800 L/（mol·cm）,6 200 L/（mol·cm）,3 800 L/（mol·cm）,7 800 L/（mol·cm） and8 400 L/（mol·cm） by Langbier’s law. Conclusion There were two kinds of uronic acids in alginate-mannuronic acid and guluronic acid,and the absorption intensity was different. In different brown algae,the contents of mannuronic acid and guluronic acid were different. The results could be corrected by the ratio of the two kinds of uronic acid and the apparent absorption coefficient.
作者
杨钊
周星彤
于甜甜
张燕
林亚先
YANG Zhao, ZHOU Xing- tong, YU Tian -tian, ZHANG Yan, LIN Ya -xian(Qingdao Institute for Food and Drug Control, Qingdao, Shandong 266000, Chin)
出处
《中国卫生检验杂志》
CAS
2018年第9期1049-1050,1053,共3页
Chinese Journal of Health Laboratory Technology
关键词
海藻酸钠
糖醛酸
硫酸咔唑法
甘露糖醛酸与古罗糖醛酸含量之比
Sodium alginate
Uronic acid
Carbazole sulfate method
Ratio of mannuronic acid to guluronic acid content
