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测定络合物稳定常数,在理论和实践上都有重大意义。近廿年来,随着学科的互相渗透,特别在化学,生物,医学方面的深入研究,测定络合物稳定常数的工作显得更加重要,并已得到广泛重视。测定络合物稳定常数的方法很多,常用的有电位法,极谱法,电流分析法,溶解度法等,其中PH滴定法、萃取法、极谱法有较多的研究和发展。在用离子选择性电极测定味精(谷氨酸的一钠盐)中微量元素时,我们发现在某个pH范围内,从仪器所读到的数值与实际含量有所不同,这是谷氨酸与pb~(2+)络合的结果,鉴于谷氨酸在食品、生物化学、医药的广泛应用,而它与某些重金属元素的络合物稳定常数报导得很不完全,(如它与pb~(2+)的络合物稳定常数未见报导)因此,进行对人体有害的重金属元素(如pb~(2+))与谷氨酸的络合物稳定常数的测定具有更大的现实意义。
Determination of complex stability constants, both in theory and practice are of great significance. In recent 20 years, with the mutual penetration of disciplines, especially in the fields of chemistry, biology and medicine, the determination of the stability constant of complexes has become more and more important and has received extensive attention. There are many methods to determine the stability constants of complexes. Potential methods, polarography, current analysis and solubility methods are commonly used. Among them, PH titration, extraction and polarography have more research and development. When measuring trace elements in MSG (monosodium glutamate) with ion-selective electrodes, we found that the value read from the instrument differs from the actual content in a certain pH range, which is the result of glutamate The complexation with Pb 2+ results in the incomplete report of the stability constant of complex with some heavy metal elements due to the wide application of glutamic acid in food, biochemistry and medicine (eg, Therefore, the determination of the stability constants of complexes of heavy metal elements (such as pb ~ (2+)) and glutamic acid that are harmful to humans has a greater Realistic meaning.