摘要
本文研究了8种氨基酸与γ-MnOOH和针铁矿之间相互作用的交换率(％)-pH曲线,该曲线为双峰型。在一定pH条件下,一定形态的氨基酸与氧化物表面基团M—O^-,M—OH或M—O进行离子交换、质子转移等反应。这些反应与氨基酸形态pH分布特点和氧化物表面基团的酸碱两性相关,由此产生了双峰型pH曲线。对于γ-MnOOH体系,出现第一个峰值的pH_(max(1))值按以下次序增大:组氨酸<天冬氨酸<赖氨酸～谷氨酸～苏氨酸<丝氨酸<甘氨酸～丙氨酸。pH_(max(2))值的大小序列是:天冬氨酸<谷氨酸<组氨酸<赖氨酸<苏氨酸<丝氨酸<甘氨酸～丙氨酸。该pH_(max(1))和pH_(max(2))值序列与氨基酸形态pH分布中pH_a和PH_b(或pH_(sum(2)))值序列一致。氨基酸与针铁矿之间的离子交换作用不如与γ-MnOOH是因为,在实验pH范围内针铁矿表面以M—OH为主,而γ-MnOOH以M—O^-为主。
The paper studies the exchange percentage (%)-pH curve, which is 'doublepeak' type, of interactions between 8 kinds of amino acid and γ-MnOOH and goet-hite. Under the condition of a certain pH, the reactions of ion exchange, protontransfer, etc, between a certain amino acid species and oxide surface group,take place, which are related to amino acid species-pH distri-bution and acid-base amphoteric property of oxide. For γ-MnOOH system, pHmax(1) values, at which the first peak locates, increase in the following order: histidine < aspartic acid < lysine^glutamic acid^theorine<serine<glycine^alanine. And pHmax(2) values increase as following: aspartic acid < glutamic acid < histidine < lysine < th-eorine < serine < glycine^alanine. The series of pHmax(1) and pHmax(2) are identical respectively with that of pH, and pHb (or pHsum(2)) values in amino acid species-pH distribution. The reason for the less ion exchange between amino acid and go-ethite than between amino acid and γ-MnOOH is that the surface hydroxyl of goe-thite is basicly , whereas that of r-MnOOH is principally.
出处
《海洋与湖沼》
CAS
CSCD
北大核心
1989年第1期34-43,共10页
Oceanologia Et Limnologia Sinica
基金
国家自然科学基金
