精氨酸在苯甲醛存在下的吸附溶出伏安法研究

On the Adsorptive Stripping Voltammetric Behavior of Arginine in the Presence of Aldehydes

在０．２ｍｏｌ／ＬＮａＯＨ－０．０４ｍｏｌ／ＬＨ３ＰＯ４－０．０２ｍｏｌ／Ｌ（ＮＨ４）２ＳＯ４－０．０４ｍｏｌ／ＬＣＨ３ＣＯＯＨ溶液中，精氨酸（Ａｒｇ）在苯甲醛存在下产生一灵敏的吸附波。实验证明电活性物质为α－苯亚甲基精氨酸，其电极反应机理是分子内α－＞Ｃ＝Ｎ基团被还原为亚胺。用该吸附波可在１×１０（－３）～２×１０（－６）ｍｏｌ／Ｌ范围内分析蛋白质中的Ａｒｇ。

The adsorptive voltammetric behavior of arginine in the presence of formaldehyde, acetaldehyde, salicylaldehyde and benzaldehyde has been investigated with a static mercury dropping electrode. The mechanism of the electrode reaction has been clarified. It was found that condensation products of aldehydes with arginine give voltammetric response. However, only α-benzylidene arginine, the condensation product of aromatic aldehydes with arginine, can share π-electrons with mercury electrode surface. Consequently, its reduction gives a more pronounced adsorptive wave. The electrode reaction is the intra-molecular reduction of the α->C=N group into the imine group. The detection limit of arginine with the linear sweep technique can reach 8×10￣(-7)mol/L. The linear range for arginine determination is 1×10￣(-3)～1×10￣(-6)mol/L. The method has been applied to the determination of arginine in protein samples.