Thermo Scientific Dionex ED50A User manual

Dionex ED50A Electrochemical Detector
Operator's Manual
Document No. 065551
Revision 01
June 2013

© 2013 Thermo Fisher Scientific Inc. All rights reserved.
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reproduction of the whole or any part of this document is strictly prohibited, except with
the written authorization of Thermo Fisher Scientific Inc.
The contents of this document are subject to change without notice. All technical
information in this document is for reference purposes only. System configurations and
specifications in this document supersede all previous information received by the
purchaser.
Thermo Fisher Scientific Inc. makes no representations that this document is complete,
accurate, or error-free and assumes no responsibility and will not be liable for any errors,
omissions, damage, or loss that might result from any use of this document, even if the
information in the document is followed properly.
Revision history: Revision 01 released June 2013
For Research Use Only. Not for use in diagnostic procedures.

Doc. 065551-01 6/13 i
Contents
1 • Introduction
1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1
1.2 Detection Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2
1.3 Control Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2
1.4 About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3
1.4.1 Safety Messages and Notes . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4
1.4.2 Declaration of Conformity . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-6
1.4.3 Safety Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-7
2•Description
2.1 Front Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1
2.1.1 Control Panel Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1
2.1.2 Control Panel Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
2.2 Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
2.3 Electronics Chassis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-7
2.3.1 Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8
2.3.2 Cards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9
2.4 Amperometry Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-10
2.4.1 Combination pH–Ag/AgCl Reference Electrode . . . . . . . . . .2-12
2.4.2 Monitoring the Amperometry Cell pH Readout . . . . . . . . . . .2-13

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2.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14
2.5.1 Operating and Control Modes . . . . . . . . . . . . . . . . . . . . . . . . 2-14
2.5.2 Local and Remote Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15
2.5.3 Method Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15
2.5.4 TTL Input Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16
3 • Operation and Maintenance
3.1 Getting Ready to Run . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.2 Initial Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
3.3 Selecting the Control Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
3.4 Running Under Direct Control (Local Mode) . . . . . . . . . . . . . . . . . . . 3-4
3.5 Running Under Method Control (Local Mode) . . . . . . . . . . . . . . . . . . 3-5
3.5.1 Running a Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
3.5.2 Changing the Running Method . . . . . . . . . . . . . . . . . . . . . . . . 3-6
3.5.3 Changing a Method-Controlled Parameter . . . . . . . . . . . . . . . 3-6
3.5.4 Creating a New Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
3.5.5 Editing an Existing Method . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
3.6 Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
3.7 Cyclic Voltammetry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
3.7.1 Cyclic Voltammetry with the Dionex ED50A . . . . . . . . . . . 3-11
3.7.2 Programming the Voltammetry Waveform . . . . . . . . . . . . . . 3-13
3.7.3 Running the Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14
3.8 Routine Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
3.9 Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16

Contents
Doc. 065551-01 6/13 iii
4 • Troubleshooting
4.1 No Detector Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1
4.2 Low Detector Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2
4.3 High Detector Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2
4.4 Noisy or Drifting Baseline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3
4.5 Tailing Peaks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-4
4.6 Amperometry Cell pH Readout Always 7.0 . . . . . . . . . . . . . . . . . . . . .4-4
4.7 Cannot Set Amperometry Cell pH Readout to 7.0 . . . . . . . . . . . . . . . .4-5
4.8 Shift in Amperometry Cell pH Readout . . . . . . . . . . . . . . . . . . . . . . . .4-5
4.9 No Amperometry Cell pH Readout or Intermittent Readout . . . . . . . .4-5
4.10 Discolored pH Reference Electrode . . . . . . . . . . . . . . . . . . . . . . . . . . .4-6
4.11 Leaking pH Reference Electrode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-6
4.12 Shift in Ag/AgCl Reference Potential . . . . . . . . . . . . . . . . . . . . . . . . . .4-7
4.13 Faulty DX-LAN Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-8
4.14 Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-9
5•Service
5.1 Eliminating Liquid Leaks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1
5.2 Polishing the Amperometry Cell Working Electrode . . . . . . . . . . . . . .5-2
5.3 Replacing the pH Reference Electrode O-Ring . . . . . . . . . . . . . . . . . . .5-4
5.3.1 Replacing the O-Ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4
5.4 Calibrating the Reference Electrode . . . . . . . . . . . . . . . . . . . . . . . . . . .5-8
5.5 Replacing the Main Power Fuses . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-10

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A • Specifications
A.1 Physical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1
A.2 Environmental . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1
A.3 Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1
A.4 Display and Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1
A.5 Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-2
A.6 Amperometry Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-2
B • Installation
B.1 Facility Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-1
B.2 Power Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-1
B.3 Overview of DX-LAN Interface Connections (Optional) . . . . . . . . . .B-2
B.4 DX-LAN Interface Connections (Optional) . . . . . . . . . . . . . . . . . . . . .B-3
B.4.1 Installing the DX-LAN Cable . . . . . . . . . . . . . . . . . . . . . . . . .B-4
B.4.2 Cascading Hubs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-4
B.5 Amperometry Cell Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-5
B.5.1 Preparing the Cell Gasket and Working Electrode. . . . . . . . . .B-5
B.5.2 Preparing the Reference Electrode . . . . . . . . . . . . . . . . . . . . . .B-6
B.5.3 Calibrating the Reference Electrode. . . . . . . . . . . . . . . . . . . . .B-7
B.5.4 Installing the Reference Electrode . . . . . . . . . . . . . . . . . . . . . .B-8
B.5.5 Connecting the Amperometry Cell Cable . . . . . . . . . . . . . . .B-12
B.5.6 Plumbing the Amperometry Cell . . . . . . . . . . . . . . . . . . . . . .B-13
B.6 Recorder/Diagnostic Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-14

Contents
Doc. 065551-01 6/13 v
C • User Interface
C.1 Operational Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-2
C.1.1 Menu of Screens—Integrated Amperometry . . . . . . . . . . . . . C-2
C.1.2 Main Screen—Integrated Amperometry . . . . . . . . . . . . . . . . . C-3
C.1.3 Detail Screen—Integrated Amperometry . . . . . . . . . . . . . . . . C-5
C.1.4 Method—Integrated Amperometry. . . . . . . . . . . . . . . . . . . . . C-6
C.1.5 Waveform—Integrated Amperometry . . . . . . . . . . . . . . . . . . C-8
C.1.6 Menu of Screens—DC Amperometry. . . . . . . . . . . . . . . . . . . C-9
C.1.7 Main Screen—DC Amperometry . . . . . . . . . . . . . . . . . . . . . C-10
C.1.8 Detail Screen—DC Amperometry . . . . . . . . . . . . . . . . . . . . C-11
C.1.9 Method—DC Amperometry . . . . . . . . . . . . . . . . . . . . . . . . . C-12
C.1.10 Menu of Screens—Voltammetry. . . . . . . . . . . . . . . . . . . . . . C-14
C.1.11 Main Screen—Voltammetry . . . . . . . . . . . . . . . . . . . . . . . . . C-15
C.1.12 Detail Screen—Voltammetry . . . . . . . . . . . . . . . . . . . . . . . . C-16
C.1.13 Waveform—Voltammetry. . . . . . . . . . . . . . . . . . . . . . . . . . . C-17
C.1.14 Module Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-18
C.1.15 Analog Out Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-19
C.1.16 Time Function In. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-20
C.2 Diagnostic Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-21
C.2.1 Diagnostic Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-21
C.2.2 Power-Up Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-22
C.2.3 Elapsed Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-23
C.2.4 Analog Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-24
C.2.5 DX-LAN Status. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-25

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C.2.6 Keyboard Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-26
C.2.7 Diagnostic Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-27
C.2.8 Leak Sensor Calibration and Status . . . . . . . . . . . . . . . . . . . .C-29
C.2.9 Signal Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-30
C.2.10 Calibrate Conductivity Cell . . . . . . . . . . . . . . . . . . . . . . . . . .C-31
C.2.11 pH Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-31
D • TTL and Relay Control
D.1 TTL and Relay Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-2
D.2 TTL and Relay Output Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-3
D.3 TTL Input Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-4
D.3.1 TTL Input Signal Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-4
D.3.2 TTL Input Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-6
E • Signal Processor Functions
F • Connector Pinouts
F.1 Recorder/Diagnostic Signal Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . . F-1
F.1.1 Signal Electrical Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . F-2
F.2 TTL/Relay Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-4
F.3 Amperometry Cell Connector Pinouts—SP . . . . . . . . . . . . . . . . . . . . . F-5
G • Reordering Information

Doc. 065551-01 6/13 1-1
1 • Introduction
1.1 Overview
The Thermo Scientific Dionex™ED50A Electrochemical Detector measures
current resulting from the application of potential (voltage) across electrodes in
flow-through cells. Depending on the method by which the potential is applied
and the current measured, several different properties of the flowing solution can
be determined. These measurements help answer the major questions analytical
chemists ask: What's in it, and how much is there?
Of course, other detectors are used in high performance liquid chromatography
(HPLC). The UV-visible absorbance detector dominates all other forms of
detection. Sensitivity is excellent for many analytes, especially aromatic species,
and transparent mobile phases are readily available. However, there are numerous
analytes that have very poor absorbance and are not detected with sufficient
sensitivity by UV absorbance. Most of these nonchromophoric molecules are
aliphatic organic molecules and inorganic ions. Low wavelength UV detection
can be used, but at a loss in selectivity. Refractive index detection can also be
used. However, maintaining a stable baseline can be difficult, and RI detection is
less sensitive and substantially less selective than UV detection.
Fortunately, a wide variety of nonchromophoric molecules can be detected with
good or excellent sensitivity by one of several forms of electrochemical detection.
These molecules include carboxylic, sulfonic, and phosphonic acids; alcohols,
glycols, aldehydes, and carbohydrates; primary, secondary, tertiary, and
quaternary amines; sulfates, sulfoxides, thiols, sulfides, and mercaptans; and
inorganic anions and cations. In addition, when compared to UV absorbance
detection, electrochemical detection provides substantial improvements in
sensitivity and selectivity for amine and hydroxy-substituted aromatics such as
catecholamines.
Several forms of electrochemical detection have become popular for certain
HPLC applications. Conductivity is the workhorse detection method in ion
chromatography, just as UV detection is for HPLC. DC amperometry is the
preferred method for neurochemical analyses. Pulsed amperometry is now
established as the superior detection method for carbohydrates. For most of the
numerous analytes listed in the previous paragraph, detection by UV-visible
absorbance is poor, while one of the three main techniques of electrochemical

Dionex ED50A Electrochemical Detector
1-2 Doc. 065551-01 6/13
detection provided by the Dionex ED50A provides superior sensitivity and
selectivity.
Electrochemical detection is not a substitute for UV-visible absorbance detection,
but is an important complement. A liquid chromatograph equipped with both a
Thermo Scientific Dionex absorbance detector and an electrochemical detector is
a versatile and powerful analytical instrument.
1.2 Detection Modes
The Dionex ED50A provides two major forms of electrochemical detection: DC
amperometry and integrated amperometry. Pulsed amperometry is a form of
integrated amperometry.
•DC Amperometric detection is based on the measurement of current resulting
from oxidation or reduction (electrolysis) of analyte molecules at the surface
of an electrode.
•Integrated and pulsed amperometric detection are similar to DC
Amperometry in that molecules are oxidized or reduced at the surface of an
electrode. However, current is measured by integration during a portion of a
repeating potential vs. time waveform.
In addition, the Voltammetry mode is used to determine potentials used in DC and
integrated amperometry.
NOTE Dionex ED50A detectors shipped in June 2013 or later
are not recommended for conductivity detection. If your
detector was shipped before June 2013, refer to ED50A
Electrochemical Detector Operator’s Manual (Document
No. 031772) for information about the Conductivity
mode. The manual is provided on the Thermo Scientific
Reference Library DVD (P/N 053891).
1.3 Control Modes
The Dionex ED50A can be controlled locally from the front panel or remotely
(via the Thermo Scientific Dionex DX-LAN™interface) from a host computer
running Thermo Scientific Dionex Chromeleon® 6.8 Chromatography Data
System and the Microsoft®Windows® XP Service Pack 3 operating system.