叶绿素铬钠盐的制备及理化性质

由菠菜叶提取叶绿素并经皂化、酸化、铬代及成盐反应制备叶绿素铬钠,测定了它的紫外可见光谱,并与叶绿素铜(II)钠盐的紫外可见光谱进行比较,同时测定了叶绿素铬钠盐理化性质。实验结果表明:叶绿素铬钠盐在360.8、401.6、655.1nm处有特征吸收峰,紫外可见光谱与叶绿素锰(III)叶绿素镧(III)相似,证明铬离子已经配位到叶绿素卟啉环上,形成了叶绿素铬钠盐。叶绿素铬钠盐能溶于水,在中性溶液中稳定,有一定的抗氧化还原性,热稳定性好,光稳定性较差。其中食盐这种食品添加剂对叶绿素铬钠盐的稳定性影响不大。

Study on Preparation and Physico-chemical Properties of Sodium Chromium Chlorophyllin from Spinach

Chlorophyll was extracted from spinach leaves. Sodium chromium (III) chlorophyllin was prepared with the chlorophyll extracted through the processes of saponification, acidification, chromiuming and salt-forming reaction. Its UV-Vis spectrum was determined in comparison with the UV-Vis of sodium copper (II) chlorophyllin. At the same time the physico- chemical properties of sodium chromium (III) chlorophyllin were determined. UV-Vis spectrum of sodium chromium (III) chlorophyllin showed that there are absorption peaks at 360.8 nm, 401.6 nm and 655.1 nm, simialr to manganese (III) chlorophyllin and lanthanum (III) chlorophyll a, as confirmed coordination of Cr (III) to the prophyrin rings. Sodium chromium (III) chlorophyllin is soluble in water, stable in the neutral solution, and resistant to oxidizing agent and reducing agent. Its thermostabillity is good, but photostability weak. Some food additives such as NaCl has little effect on sodium chromium (III) chlorophyllin.