Silver/silver chloride reference electrode – the ecological alternative for calomel reference electrodes



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Replace your calomel electr eener now!

Metrohm silver/silver chloride electr and make your chemistry gr In potentiometry the measuring setup always con sists of two electrodes, the measuring and the reference electrode. The reference electrode main tains a reproducible and long-term stable reference potential.

In the past, the saturated calomel electrode (SCE) which is based on the reaction between elemental mercury and mercury (I) chloride was used for this purpose. The saturated calomel electrode contains mercury which is known to be a health hazard and harmful to the environment. Therefore mercury is under strong regulations (e.g. «Mercury Export Ban Act of 2008», «Minamata Conven tion on Mercury (2013)”) which complicates or even pro

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bits the import, production, distribution, and/or ex port of items containing elemental mercury or other mer cury compounds.

Therefore, calomel electrodes have been replaced by silver based reference electrodes. The silver/silver chloride (Ag/AgCl) reference electrode is nowadays the most widely used reference electrode for potentiometric measurement and can be applied for the same applications as the SCE.

The United States Pharmacopeia (USP) monograph <541> Titrimetry even recommends to replace the calomel electrode by the silver/silver chloride reference electrode.

Ag/AgCl Reference Electrodes



Metrohm offers several Ag/AgCl reference electrodes for your applications

6.0726.100

Ag/AgCl DJ reference electrode, plug­in head B

6.0729.100

Ag/AgCl DJ reference electrode, plug­in head G

6.0750.100

LL ISE Reference

­9100 Herisau

G, CH

ohm A

witzerland by Metr

www.metrohm.com

, printed in S

SW

­02

Subject to change

Layout by Ecknauer+Schoch A 8.109.5022EN – 2018