15 SenCell
15.1 The electrochemical flow cell
15.1.1 Introduction
The SenCell, a new electrochemical flow cell for (U)HPLC with ECD, has several unique
features, such as a stepless adjustable working volume (spacerless concept) and toolless
assembly.
The SenCell is available with a glassy carbon working electrode (WE). The SenCell design
eliminates the use of plastic or metal spacers. By means of a special key, the working volume of
the electrochemical cell can be steplessly adjusted without opening the cell, allowing easy
optimization of the detection sensitivity for any LC application. The working volume can be
adjusted between 0 and 300 nL (based on a WE of 2-mm diameter). The salt bridge Ag/AgCl
reference electrode is generally recommended. For special applications, the HyREF reference
electrode is available. A third reference electrode option is the in situ Ag/AgCl (ISAAC).
Figure 15–1: Assembled SenCell electrochemical flow cell with ISAAC inlet block (green).
The upper part, the inlet block, is separated from the working electrode block. Right:
SenCell WE block
The SenCell has been developed for ultra-trace analysis in standard, microbore, and capillary
LC-EC. After extensive testing it was established that the confined wall-jet configuration gives the
best results. In addition, it was found that the electrode materials quality and the finishing of the
electrodes in the flow cell are decisive factors for the performance of an EC detector. While
competitive designs usually deteriorate when in use, this flow cell, by design, improves in
performance. The flow cell permits unusually short stabilization times; trace analysis within a few
hours after startup may be expected.
15.1.2 Three-electrode configuration
A three-electrode configuration is used in the SenCell. The working potential is set between the
working electrode (WE) and the auxiliary electrode (AUX). The AUX is kept at a precisely defined
December 16, 2021, 715007395 Ver. 00
Page 123
