Customized pH electrode structure, function and type [Common sense]

The structure of the pH electrode includes glass membrane, junction, internal solution, reference system and reference electrolyte etc. The manufacture and assembly of each part of the customized pH electrode is the fusion of professional technology and craftsmanship.

glass film

The glass membrane is a sensitive membrane for the pH electrode to react to the H+ activity of the solution. The quality of the glass membrane depends on type and shape of the membrane, which is the core technology of the pH electrode.

The shape of the glass membrane

Junction

The junction is the connection interface between the reference system and the sample solution, and the custom electrode adopts the junction of the following structure.

reference system

●Long-life reference system—consists of a thin glass tube, silver chloride particles and silver wire. The head of the thin glass tube is stuffed with cotton. This structure contains sufficient silver chloride particles, which can further ensure the long-term stability of the reference electrode. , The reference electrolyte used with the long-life reference system does not contain silver ions, which prevents the reaction with the sulfide and protein in the sample to produce precipitation and block the junction.

Silver ion trap reference system - the silver ion trap reference system is a combination of "long-life reference system" and "silver ion trap". There is no Ag+ in the electrolyte, so as to avoid the blockage of the junction caused by samples containing sulfide and protein or TRIS buffer.

reference electrolyte

In addition to the routinely used 3M KCl solution and gel, this custom electrode also uses the following special reference electrolytes:

• Solid polymer reference electrolyte - using an open junction, the polymer is in direct contact with the sample, and the pressure is 6 bar, which is suitable for almost all measurement fields, including oily samples, low ion samples, protein samples and suspended matter samples.

• Protelyte reference electrolyte - suitable for protein samples, low temperature samples and viscous samples.

• Pre-pressurized reference electrolyte - a pressurized system is set in the gel electrolyte to ensure that the electrolyte can continue to seep out even in viscous samples.