脱镁叶绿酸钙结构的络合滴定-质谱分析

Analysis of the pheophorbide calcium's structure by complexometric titration coupled to mass spectrometry

叶绿素衍生物作为食品添加剂具有绿色、安全等特点,以糊状叶绿素为原料,经过皂化、酸化、成盐过程制备了脱镁叶绿酸钙。络合滴定法确定了叶绿酸二钠与钙离子的结合比例为1∶1,ESI质谱分析确定脱镁叶绿酸钙相对分子质量为1259.4,并对m/z分别为1067.5、889.2、727.2、767.2、657.3、581.3、551.3的碎片离子进行了谱图解析。利用化学分析与仪器分析结果,理论推测并计算,获得脱镁叶绿酸钙结构为二聚体型,其分子式为脱镁叶绿酸a钙:(C34H32O5N4)2Ca2;脱镁叶绿酸b钙:(C34H30O6N4)2Ca2。理论平均相对分子质量为1263.51g/mo L。

Chlorophyll derivatives as fine chemicals have the features of green and security. Paste chlorophyll as the raw material,preparation of pheophorbide calcium through saponification,acidification and salt preparation. Complexometric titration method determined the chlorophyllin of two sodium and calcium ion combined with the ratio of 1∶1. According to ESI mass spectrometry determined the relative molecular mass of pheophorbide calcium is 1259.4,and carried out spectral analysis on the fragment ions of m/z 1067.5, 889.2, 727.2, 767.2, 657.3, 581.3, 551.3. Using of chemical analysis and instrumental analysis results,theoretical predictions and calculation,obtained pheophorbide calcium＇s structure is two poly type,its molecular formula is（C34H32O5N4）2Ca2 of pheophorbide calcium a.（C34H30O6N4）2Ca2 of pheophorbide calcium b. The theory of average relative molecular mass is 1263.51.