Handling, glass membrane electrodes

The lifespan of glass membrane electrodes can reach many years. Most are mechanically destroyed much sooner through careless handling. 

The commercially available heterogeneous solid-state membrane electrodes should be conditioned in a 0.1 M solution of the ion to be measured for about 2 hours before the first measurement. With self-made electrodes having materials which are not ion-conductors, a conditioning in a 1 M measured ion solution at 90°C is recommended. Drying out of the active phase is to be avoided, since the accompanying shrinkage can cause fine cracks in the membrane. Such electrodes are best handled like glass membrane electrodes, and stored in a 0.01 to 0.1 M solution of the indicated ion between measurements. 

Among the membrane electrodes, the glass pH electrode is by far the most important pH electrode in non-aqueous media in fact, there seem no real limitations to its use, if proper handling is adopted. 

To diminish electrode pore flooding, McHenry and Winnick [106] studied new membrane formulations which included borosilicate glass and zeolites. These showed improved electrolyte retention and polarization behavior as compared with MgO-based membranes. The reduction in flooding allowed the cell to handle three times the current for the same applied overpotential. The same authors [107] also found that Lao,8Sro.2Co03 electrodes reacted with the molten pyrosulfate electrolyte. Lithium-doped nickel oxide replacement electrodes, however, were not degraded. 

Place and align embryos in the chamber. Alignment consists of orienting embryos such that the membranes to be fused are parallel to the electrodes (Fig. 3). This is done with a glass embryo-handling pipette. 

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