Equitransference reference electrolytes

The reference electrode (system) and its stability in clinical analyzers is a crucial problem because all typical ISSs (and GSSs) use this electrode. Currently silver chloride electrodes are used. They work in two systems an open liquid junction or a constraint liquid junction with concentrated KC1 (>2M) or sodium formate (4M) as the equitransferent hypertonic electrolyte bridge. The latter better serves whole blood measurements. 

Many of the problems associated with the liquid junction are common to all reference electrodes, while others are confined primarily to the microcapillary electrodes and/or measurements in fluids containing polyelectrolytes and colloidal or suspended components. There are several factors which affect the liquid junction potential of most reference electrodes. One of the most important factors is the mobility and concentration of the bridge electrolyte vis-a-vis the sample electrolyte. Usually the salt bridge solution is chosen to have a high concentration of equi-transferent ions. In this way, conditions are established for the transport of charge at the liquid junction by the salt bridge electrolyte, which, if equitransferent, results in a minimal diffusion potential. 

In a process of repeated oxidation and reduction of the same polymer film with the same charge, it is possible to dope the CP with a salt MX, in particular for immobile andX [13]. This occasion is of importance for reference elements in which MX, in particular equitransferent MX, plays a role of junction electrolyte. 

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