22
HTEC-500
11.
ECD Operation
Attention
• The tip of the reference electrode should be soaked in mobile phase or lithium chloride solution.
• The reference electrode needs to be replaced to a new one once a year, even if it is not used.
• The graphite working electrode (WE-3G) cannot be used and stored at the condition of 30%
methanol.
11-1. Basics
The ECD cell consists of three types of electrodes. These include the working electrode, the reference
electrode and the counter electrode. The electrochemically active substances are eluted from the
separation column and then electrolyzed by the working electrode in the electrode system. A current is
produced by electrolysis and this is in proportion to the concentration of the substances to be
measured. This current is converted to a voltage in the amplifier and an output is given from the
integrator. 0.1 nA generated in the cell equals to 1 mV on the output of the integrator.
0.1 nA = 1 mV
Handle
Shaft
Outlet
Inlet
Reference Electrode
Cell Block
Fig. 21 (a) ECD Cell
Counter Electrode
Gasket
Working Electrode (with holder)
Setting Plate
Reference Electrode
Shaft
Outlet
(Silicon 3
×
1 mm and
Teflon 1.6
×
1 mm)
Fig. 22 (b) ECD Cell
Cell Block (PEEK)
Flow
