*2.2.4 Electrochemical methods*

These methods can include amperometric titration, which is mentioned under the title of iodometric methods. Amperometric analyzers use an electrochemical cell to determine the ozone. There are two types of analyzer [25]:


In the literature, there are various electrochemical methods using a solid redox polymer electrolyte-based amperometric sensor, a lignin-modified, glassy carbon electrode, and multiwalled carbon nanotubes to analyze ozone [16].

General advantages of electrochemical methods are low cost, easy operation, potential for miniaturizing and automation, simple portable devices for fast screening purposes, and in-field/onsite monitoring [16]. But every 1 or 2 months, amperometric analyzers have to be calibrated against a reference method such as UV, or the colorimetric indigo methods [25].
