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本文研究了用氢离子载体制备的PVC膜pH敏感电极。对约60种含胺氮及其他能质子化基团的有机化合物尤其是一系列脂肪族芳香族叔、仲、伯胺进行了试验,比较了相应膜电极的电位响应特性。实验发现总碳原子数大于或等于24的长链叔胺及某些仲胺例如Amberlite LA—1及Amberllte LA—2是有实用价值的氢离子载体化合物。对用甲基二正十八胺(MDODA)及Amberlite LA—2作电活性物质制备的PVC膜pH电极作了较详细的研究,提出了合成MDODA的较简易方法。在比较了近十种增塑剂对电极性能影响的基础之上,有关电极的膜组成使用正交设计试验法进行了优化,例如,选定活性物MDODA。增塑剂癸二酸二异辛酯(DIOS)、阴离子定域体NaTPB(四苯硼钠)及膜基质PVC作为电极敏感膜的组成成分,实验确定电极的最佳膜组成为:1.1％MDODA;约66％DIOS;0.2～0.3％NaTPB;32％左右PVC。借下列电化学池:
In this paper, a PVC membrane pH-sensitive electrode prepared with a hydrogen ionophore was studied. About 60 kinds of organic compounds containing amine nitrogen and other protonatable groups, especially a series of aliphatic aromatic tertiary, secondary and primary amines were tested. The potential responses of the corresponding membrane electrodes were compared. Long-chain tertiary amines and some secondary amines such as Amberlite LA-1 and Amberllte LA-2 which have been found to have a total number of carbon atoms greater than or equal to 24 have been found to be valuable hydrogen ion-bearing compounds. The PVC membrane pH electrode prepared by using MDODA and Amberlite LA-2 as electroactive materials was studied in detail. A simple and convenient method for synthesizing MDODA was proposed. Based on a comparison of the influence of nearly ten plasticizers on the electrode performance, the membrane composition of the electrode was optimized using an orthogonal design test, for example, selecting the active substance MDODA. DIOS, NaTPB (sodium tetraphenylborate) and PVC were used as the components of the electrode-sensitive membrane. The optimum membrane composition of the electrode was determined as follows: 1.1% MDODA About 66% DIOS, 0.2-0.3% NaTPB, and about 32% PVC. By the following electrochemical cell: