Thermo Scientific 500 User manual

Part of Thermo Fisher Scientific
Thermo Scientific
Dionex CRS 500
Product Manual
P/N: 031727-07 March 2015

Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 2 of 40
031727-07
Product Manual
for
Dionex Chemically Regenerated Suppressor 500
Dionex ACRS 500, 4 mm, (P/N 085090)
Dionex CCRS 500, 4 mm, (P/N 085092)
Dionex ACRS 500, 2 mm, (P/N 085091)
Dionex CCRS 500, 2 mm, (P/N 085093)

Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 3 of 40
031727-07
© 2015 Thermo Fisher Scientific Inc. All rights reserved.
All trademarks are the property of Thermo Fisher Scientific Inc. and its subsidiaries.
Thermo Fisher Scientific Inc. provides this document to its customers with a product purchase to use in the product
operation. This document is copyright protected and any 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 supers
ede 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.
This document is not part of any sales contract between Thermo Fisher Scientific Inc. and a purchaser. This
document shall in no way govern or modify any Terms and Conditions of Sale, which Terms and Conditions of Sale
shall govern all conflicting information between the two documents.
For Research Use Only. Not for Use in Diagnostic Procedures.
Revision History:
Revision 06, January, 2015 – Rebranded for Thermo Scientific. Product name changed from Dionex MMS 300 to
CRS 500.
Revision 07, March, 2015 – Typo and formatting corrections.

Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 4 of 40
031727-07
Safety and Special Notices
Make sure you follow the precautionary statements presented in this guide. The safety and
other special notices appear in boxes.
Safety and special notices include the following:
Indicates a potentially hazardous situation which, if not avoided, could result in death or
serious injury.
Indicates a potentially hazardous situation which, if not avoided, could result in damage to
equipment.
Indicates a potentially hazardous situation which, if not avoided, may result in minor or
moderate injury. Also used to identify a situation or practice that may seriously damage the
instrument, but will not cause injury.
Indicates information of general interest.
IMPORTANT Highlights information necessary to prevent damage to software, loss of data, or invalid test
results; or might contain information that is critical for optimal performance of the system.
Tip Highlights helpful information that can make a task easier.
SAFETY
!
WARNING
!
CAUTION
!
NOTE
!

Contents
Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 5 of 40
031727-07
Contents
1. Introduction.........................................................................................................7
1.1 Chemically Regenerated Suppressor..............................................................................................7
1.2 Dionex Chemically Regenerated Suppressor Assembly Schematic...............................................9
1.3 Chemical Suppression Schematic.................................................................................................11
1.4 Shipment and Storage...................................................................................................................12
1.4.1 Shipment .............................................................................................................................................12
1.4.2 Storage ................................................................................................................................................12
1.5 Overview of Suppression Modes..................................................................................................13
1.6 Mode of Operation Selection........................................................................................................14
1.6.1 The Displacement Chemical Regeneration (DCR) Mode...................................................................15
1.6.2 The External Chemical Mode .............................................................................................................16
1.6.3 The AutoRegen Suppression Mode.....................................................................................................17
2. Installation.........................................................................................................18
2.1 System Requirements...................................................................................................................18
2.2 Back Pressure Coils for the Dionex CRS 500..............................................................................19
2.3 Plumbing for Displacement Chemical Regeneration (DCR) Mode of Operation........................21
2.4 Plumbing for External Chemical Mode of Operation...................................................................23
2.5 Peristaltic Pump installation.........................................................................................................24
2.6 Plumbing for AutoRegen Suppression Mode of Operation..........................................................25
3. Operation...........................................................................................................27
3.1 Chemical Purity Requirements.....................................................................................................27
3.1.1 Inorganic Chemicals............................................................................................................................27
3.1.2 Solvents...............................................................................................................................................27
3.1.3 Deionized Water..................................................................................................................................27
3.2 Start Up.........................................................................................................................................28
3.3 Optimizing Regenerant Concentration and Flowrate...................................................................29
3.3.1 Anion Regenerant Concentration for Optimized Operation in
External Chemical and AutoRegen Modes .........................................................................................29
3.3.2 Cation Regenerant Concentration for Optimized Operation for
External Chemical and AutoRegen Modes .........................................................................................30
3.3.3 Calculations for Regenerant Concentration.........................................................................................32
3.3.4 Regenerant Concentration for DCR Mode..........................................................................................33
3.4 Storage..........................................................................................................................................33
3.4.1 Short Term Storage (1 to 5 days)........................................................................................................33
3.4.2 Long Term Storage .............................................................................................................................33

Contents
Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 6 of 40
031727-07
4. Troubleshooting Guide.....................................................................................34
4.1 Small Analyte Peak Areas............................................................................................................34
4.2 High Background Conductivity....................................................................................................34
4.3 Drifting Baseline...........................................................................................................................35
4.4 Decreased Sensitivity ...................................................................................................................36
4.5 System Back Pressure Increases Over Time ................................................................................36
4.6 Liquid Leaks.................................................................................................................................37
5. Suppressor Cleanup..........................................................................................38
5.1 Base-Soluble Contaminants or Precipitates with the Dionex CRS 500........................................39
5.2 Organic Contaminants with the Dionex ACRS 500 or Dionex CCRS 500..................................40

1– Introduction
Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 7 of 40
031727-07
1. Introduction
Suppressor: The role of a suppressor in Ion Chromatography is to remove the eluent and sample
counterions and replace this with regenerant ions thereby converting the eluent to a weakly
dissociated form prior to detection. Detection of analyte ions particularly with conductivity
detection is therefore feasible against a low background. The suppressor not only reduces the
background signal but also the noise associated with the signal. Furthermore, the analytes are
converted to the more conductive acid or base form, which enhances the signal, particularly for
fully dissociated species. Thus overall improvement in detection limits as observed from the
signal to noise ratio is achieved. When compared to single column ion chromatography, i.e.,
applications that do not use a suppressor, the improvement in noise with suppressed ion
chromatography far exceeds the noise performance of single column chromatography
applications. Hence the suppressor has become an integral part of the ion chromatography
instrument.
The suppressors from Thermo Fisher Scientific are designed for continuous operation and do
not require any switching or offline regeneration. Furthermore, the standards and the samples
are always exposed to the same suppressor device when pursuing ion analysis, thus ensuring
that the analytical parameters are consistent between calibration and analysis. From a simplistic
perspective there are two types of suppressors offered for continuous operation, namely,
electrolytically regenerated suppressors and chemically regenerated suppressors. The
electrolytic suppressors operate continuously with a water source as a regenerant. In the recycle
mode of operation the water source is derived from the suppressed eluent, thereby making the
suppressor operation facile. The chemical suppressors operate continuously with an external
regenerant source.
The electrolytic suppressor also is a device that permits recycle of the eluent when installed in a
system with Eluent Recycle (ER) system.
1.1 Chemically Regenerated Suppressor
The Thermo Scientific™ Dionex™ Chemically Regenerated Suppressor (Dionex CRS™ 500)
replaces the Dionex MicroMembrane Suppressor (MMS 300) product line. The Dionex CRS
500 is a chemical suppressor with a new hardware design that allows the suppressor to be more
pressure tolerant than previous generation suppressor devices. The suppressor flow pathway has
been redesigned to optimize band dispersion, improve the flow and sealing properties. The
Dionex CRS 500 continues to use the same cleaned ion exchange components (screens and
membranes) as the Dionex MMS 300 suppressor devices; however the Dionex CRS 500 eluent
channel uses an ion exchange resin bed as opposed to a gasketed screen.
The Chemically Regenerated Suppressor (CRS 500) is available in two versions: the Anion
Chemically Regenerated Suppressor (Dionex ACRS™ 500) or Cation Chemically Regenerated
Suppressor (Dionex CCRS™ 500) to support anion and cation analysis applications.

1– Introduction
Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 8 of 40
031727-07
Figure 1 The Chemical Suppression System
The Dionex Chemically Regenerated Suppressors, Dionex Anion Chemically Regenerated
Suppressor (Dionex ACRS 500) and the Dionex Cation Chemically Regenerated Suppressor
(Dionex CCRS 500), provide a high performance, highly reliable, low maintenance chemical
suppression system for Ion Chromatography.
The chemical suppression system consists of the Dionex CRS 500 and a source of chemical
regenerant. Through an ion exchange based neutralization reaction in the Dionex CRS 500
Suppressor device, the eluent is converted to a weakly dissociated lower conductivity form
while the analytes are converted typically to a more conductive form.
The Dionex CRS 500 is a non-electrolytic device and therefore requires no power supply.
Installation of equipment (either the Displacement Chemical Regeneration (DCR) kit, a
pressurized bottle delivery system, additional pump or the AutoRegen Accessory) is needed in
conjunction with the Dionex CRS 500. This equipment facilitates the delivery of the regenerant
to the Dionex CRS 500 suppressor. A regenerant controller Thermo Scientific™ DionexTM
SRD-10 Suppressor Regenerant Detector is recommended to monitor the chemical regenerant
flow and trigger when to replace the chemical regenerant. If the regenerant flow is restricted or
stops the SRD-10 automatically disables the eluent pump.
The Dionex CRS 500 provides high capacity suppression while adding minimum dead volume
to the analytical system. The ability of the Dionex ACRS 500 to provide continuous suppression
of traditional eluents, and more concentrated eluents up to 100 mM NaOH, significantly
expands the capabilities and simplifies the operation of anion exchange Ion Chromatography.
The ability of the Dionex CCRS 500 to provide continuous suppression of traditional eluents,
and more concentrated eluents up to 75 mM HCl, significantly expands the capabilities and
simplifies the operation of cation exchange Ion Chromatography.
The Dionex ACRS 500 and Dionex CCRS 500 are available in both 4 mm and 2 mm formats
for use with 4 mm and 2 mm Ion Chromatography columns and systems respectively. The 4 mm
Dionex CRS 500 is designed to ensure optimum performance with 4 and 5 mm columns. The 2
mm Dionex CRS 500 is designed with reduced internal volume to ensure optimum performance
with, 2 and 3 mm columns and systems.
Regenerant is pumped in
Regenerant is Diverted to Waste
or
Recycled to AutoRegen Module
Eluent In
From Analytical Column
Eluent Out
To Detector Cell
with Back Pressure Coils
and then to Waste
or
to DCR Reservoir

1– Introduction
Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 9 of 40
031727-07
For assistance, contact Technical Support for Dionex Products. In the U.S., call 1-800-
346-6390. Outside the U.S., call the nearest Thermo Fisher Scientific office.
1.2 Dionex Chemically Regenerated Suppressor Assembly Schematic
The Dionex CRS 500 includes two regenerant compartments and one eluent compartment
separated by ion exchange membranes. The central channel is the eluent channel and the two
side channels are regenerant channels. Two PEEK plates form the outer walls of the regenerant
channels and have the ¼-28 ports for connecting the regenerant liquid lines. The eluent channel
is defined by a PEEK plate that seals against the ion exchange membrane and a thin elastomeric
o-ring installed on the regenerant PEEK plates. The eluent in and out ports are independent
ports that define the fluidic pathway, which is similar to a column The regenerant flow direction
is opposite to the eluent flow direction. This orientation ensures complete regeneration of the
device.
The regenerant channels are flushed with a regenerant that supplies hydronium or hydroxide
ions that are required for the suppression reaction. For the Dionex ACRS 500, the ion exchange
membranes provide the transport pathway for the hydronium ions into the eluent channel while
providing a transport pathway for the sodium or potassium ions out of the eluent channel. For
the Dionex CCRS 500, the ion exchange membranes provide the transport pathway for the
hydroxide ions into the eluent channel while providing a transport pathway for the sulfate or
MSA ions out of the eluent channel. In the Dionex CRS 500 the regenerant channel is fitted
with unfunctionalized neutral regenerant screens that facilitate excellent transport of ions to and
from the ion exchange membranes without any retention in the regenerant channel. The net
result for both the Dionex ACRS 500 and the Dionex CCRS 500 is suppression or conversion of
the eluent from a highly conductive form to a weakly conductive form and conversion of most
analytes into highly conductive forms.
For example, for the Dionex ACRS 500, sodium hydroxide eluent with residual carbonate is
converted to water and a weakly conductive carbonic acid background, while sodium chloride
analyte is converted to a highly conductive hydrochloric acid form. Thus the analyte, chloride, is
detected as the highly conductive HCl form against a low conductivity water and residual
carbonic acid background. For the Dionex CCRS 500, methanesulfonic acid eluent is converted
to water and the analyte, sodium chloride, is converted to sodium hydroxide. Thus sodium is
detected as the highly conductive NaOH form against a low conductivity water background. It
should be noted that the background of the suppressed eluent may be elevated due to chemical
leakage of the regenerant into the eluent; therefore optimization of the regenerant type,
concentration and flow rate may be needed to minimize this effect.
NOTE
!

1– Introduction
Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 10 of 40
031727-07
Figure 2 Membrane and Flow Chamber Configuration in the Dionex Chemically
Regenerated Suppressors
Regen In
Regen Out Eluent In
Eluent Out

1– Introduction
Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 11 of 40
031727-07
1.3 Chemical Suppression Schematic
Chemical Suppression with the Dionex ACRS 500 is a neutralization reaction and selective
desalting process carried out across a pair of cation exchange membranes. The cation exchange
membranes facilitate the selective exchange of cations in the suppressor. With sodium
hydroxide as the eluent, sodium ions are continuously exchanged for hydronium ions from the
regenerant acid and combine with the eluent hydroxide to form water. The sodium ions are
removed continuously from the suppressor by the regenerant acid stream thus effecting
continuous suppression.
Chemical Suppression with the Dionex CCRS 500 is a neutralization reaction and selective
desalting process carried out across a pair of anion exchange membranes.. The anion exchange
membranes facilitate the selective exchange of anions in the suppressor. With methanesulfonic
acid as the eluent, the methanesulfonate ions are continuously exchanged for hydroxide ions
from the regenerant base (TBAOH) and combine with the eluent hydronium to form water. The
methanesulfonate anions are removed continuously from the suppressor by the regenerant base
stream thus effecting continuous suppression.
Figure 3 Figure 4
Chemical Suppression with the Chemical Suppression with the
Dionex Anion Chemically Regenerated Dionex Cation Chemically Regenerated
Suppressor (Dionex ACRS 500) Suppressor (Dionex CCRS 500)

1– Introduction
Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 12 of 40
031727-07
1.4 Shipment and Storage
1.4.1 Shipment
The Dionex Chemically Regenerated Suppressors (Dionex ACRS 500 and Dionex CCRS
500) should not be subjected to temperatures above 60°C during shipment,
storage or
operation for extended periods of time.
1.4.2 Storage
Ensure the suppressor is stored in a temperature controlled environment away from direct
exposure to sunlight or other sources of heat. Do not store the suppressor in a non-
temperature controlled environment where temperatures in excess of 40°C are commonly
experienced, such as a parked car, a tool shed, or a lab-bench in close proximity to an open
window with direct sunlight.
CAUTION
!
CAUTION
!

1– Introduction
Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 13 of 40
031727-07
1.5 Overview of Suppression Modes
Three basic modes of suppression can be used with the Dionex Chemically Regenerated
Suppressor (Dionex CRS 500):
Displacement Chemical Regeneration Mode:
This mode is a self-contained means of dispensing regenerant into the Dionex CRS 500 without
any added pumps or delivery systems. The suppressed effluent from the suppressor is directed
from the cell outlet into a closed bottle containing the regenerant. A second line is connected
back from the bottle into the REGEN IN port of the suppressor. Thus the cell effluent drives the
regenerant out of the bottle and into the Dionex CRS 500; the difference in density of the eluent
and regenerant solutions prevent mixing of the two. In this mode, the eluent flow rate
determines the regenerant flow rate.
The density of the cell effluent and the regenerant determines the exact location of the line
inside the bottle. For detailed plumbing and operation instructions refer to the DCR Kit Manual
(Document No. 031664).
External Chemical Mode:
This mode in the simplest form uses an external regenerant reservoir that is gas pressurized and
dispenses regenerant into the suppressor. The pressure on the container, the liquid level and the
back pressure of the Dionex CRS 500 suppressor and associated tubing determines the flow rate
of the regenerant into the suppressor. An external pump could also be used to dispense the
regenerant, provided the pump is substantially pulse free or has a suitable pulse damper
installed.
AutoRegen Suppression Mode:
This mode has been discontinued by Thermo Scientific and is only included here for legacy
operators.
AutoRegen Suppression mode recycles the regenerant thus enabling continuous operation. A
pump is required in this mode to pump the expended regenerant back into an AutoRegenerant
cartridge to exchange the cations for hydronium ions (Dionex ACRS 500) or the anions for
hydroxide ions (Dionex CCRS 500). Thus, fresh regenerant is made available for the
suppression function.
The following sections explain which mode to use for an application. Once the mode of
operation is determined, more detailed plumbing configuration and operating instructions can be
found in Section 3, “Dionex Chemically Regenerated Suppressor (Dionex CRS 500)
Operation.”

1– Introduction
Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 14 of 40
031727-07
1.6 Mode of Operation Selection
The Dionex ACRS 500 uses sulfuric acid as the preferred regenerant to achieve eluent
suppression. The Dionex CCRS 500 uses tetrabutylammonium hydroxide (TBAOH) as the
preferred regenerant to achieve eluent suppression. Both the Dionex ACRS 500 and Dionex
CCRS 500 mode of operation is highly dependent on the ionic strength or concentration of the
eluent used and the analysis sensitivity requirements.
Table 1 Eluent Composition and Suppression Mode Compatibility
Eluent
Composition
Displacement Chemical
Regeneration Mode
External Chemical
Mode
AutoRegen
Suppression
Aqueous Eluents
Yes
Yes
Yes
Eluents Containing
Organic Solvents
Yes
Yes
Yes
Eluents Containing
Ion Pair Reagents
with/without Solvents
Yes
Yes
Yes

1– Introduction
Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 15 of 40
031727-07
1.6.1 The Displacement Chemical Regeneration (DCR) Mode
The DCR Mode is the easiest mode to implement and provides convenient and economical
operation in which the regenerant is displaced from the regenerant reservoir using the
conductivity cell effluent. This mode delivers regenerant to the suppressor at a flow rate equal to
the eluent flow rate. In this mode the regenerant bottle is completely filled with regenerant upon
startup. As the cell effluent is pumped into reservoir it displaces the regenerant solution into the
Dionex CRS regenerant chambers. No additional pump or pressure is required. Eluent and
regenerant bottles are of equivalent volumes ensuring that the regenerant solution lasts as long
as the eluent; thus new regenerant needs to be prepared only when new eluent is prepared.
The DCR Mode is recommended for low to medium suppression applications (< 50 ueq/min)
and provides adequate dynamic capacity for the majority of applications. Because regenerant
flow rate is limited to the same flow rate as the eluent, the concentration of the regenerant may
need to be adjusted to achieve full suppression; this may result in increased background
conductivity compared to other modes where the flow rate can be adjusted. As a general rule the
regenerant concentration in mN should be 2 to 5 times the eluent concentration in mN.
Figure 5 The Displacement Chemical Regeneration (DCR) Mode Diagram
Regenerant
Regen
IN
Regen
OUT
Eluent
OUT
Eluent
IN
Injection
Valve
Guard
Column
Analytical
Column
Waste Cell

1– Introduction
Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 16 of 40
031727-07
1.6.2 The External Chemical Mode
The External Chemical Mode is an easy to implement configuration that dispenses regenerant
using a pressurized regenerant reservoir directly into the suppressor. The concentration of the
regenerant dictates the leakage into the eluent stream therefore lower concentration of the
regenerant is preferred in this mode. The flow rate needs to be adjusted to provide the equivalent
concentration required for suppression. Generally higher flow rates are employed in this
mode resulting in higher waste generation. The regenerant dynamic concentration (mN x
mL/min) should be approximately 7 times the eluent dynamic concentration (mN x mL/min).
The External Chemical Mode is highly recommended for high suppression applications (> 70
µeq/min) and provides the highest dynamic capacities required for these applications.
An external pump could be used for dispensing the regenerant provided the pump is
substantially pulse dampened using a suitable pulse damper. Thermo Scientific recommends the
use of a Peristaltic Pump P/N 064230 along with a Peristaltic Pump Kit (P/N 064911) for this
application.
Figure 6 The External Chemical Mode with the Dionex Chemically Regenerated
Suppressor (Dionex CRS 500)
Regenerant
Regen
IN
Regen
OUT
Eluent
OUT
Eluent
IN
Injection
Valve
Guard
Column
Analytical
Column
Waste
Cell
Gas Pressure
25 psi max
Coil #1
Coil #2

1– Introduction
Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 17 of 40
031727-07
1.6.3 The AutoRegen Suppression Mode
This mode has been discontinued by Thermo Scientific and is only included here for legacy
operators.
The AutoRegen Suppression Mode is another mode for implementing chemical suppression.
This mode is designed to recycle the regenerant and reduce regenerant consumption for high
suppression applications. For the Dionex ACRS 500, the AutoRegen Suppression mode requires
the installation of the AutoRegen Accessory equipped with an AutoRegen Regenerant Cartridge
to convert the spent regenerant back to sulfuric acid regenerant. For the Dionex CRS 500, the
AutoRegen Suppression mode requires the installation of the AutoRegen Accessory equipped
with an AutoRegen Regenerant Cartridge to convert the spent regenerant back to TBAOH
regenerant. The AutoRegen Suppression Mode is recommended for applications that require
continuous operation without user intervention. The AutoRegen Mode however, is not
recommended for applications requiring low noise or high sensitivity.

2– Installation
Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 18 of 40
031727-07
2. Installation
2.1 System Requirements
The Dionex Anion or Cation Chemically Regenerated Suppressor (Dionex CRS 500) is
designed to be run on any Dionex Ion Chromatograph (IC) equipped with an ion exchange
column set and suppressed conductivity detection. The Dionex CRS 500 is installed
immediately after the analytical column and before the conductivity detector cell. The
following components are required for the installation of the Dionex CRS 500 in a Dionex Ion
Chromatograph:
Required Installation Components
P/N
Description
Back pressure coils:
45877
Backpressure coil 4 mm
45878
Backpressure coil 2 mm
Also Found in:
46297
ED40 Shipkit
46298
CD20 Shipkit
45935
CDM-3 On-Line Ship Kit
50130
DX-120 Ship Kit
Tubing for 4 mm systems:
45825
Standard tubing
(containing tubing, fittings and 4 mm backpressure coils required for plumbing a
4 mm systems)
Tubing for 2 mm / 3 mm systems:
52324
Microbore tubing
(containing tubing, fittings and 2 mm backpressure coils required for plumbing a
2 mm and 3 mm systems)
Regenerant Options:
Pressurized Water Delivery System (used with the External Pressurized Bottle
Mode, the Chemical Suppression Mode, or the MPIC Suppression Mode)
38018
Dionex CRS/SRS Installation Kit
64230
Peristaltic Pump
64911
Peristaltic Pump Kit
AutoRegen Accessory (used with the Chemical Suppression Mode)
39594
115 V ac Version
39608
230 V ac Version
39564
Anion Regenerant Cartridge
39563
Cation Regenerant Cartridge
Displacement Regeneration Kit
56882
Displacement Regeneration 2 Liter Kit
56884
Displacement Regeneration 4 Liter Kit

2– Installation
Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 19 of 40
031727-07
During the course of installing and using the Dionex CRS 500
, it may be necessary to
assemble 1/4-28 or 10-32 ferrule/bolt style liquid lines. See, “Dionex Liquid Line Fittings,”
for complete details.
2.2 Back Pressure Coils for the Dionex CRS 500
All detector cells require enough back pressure to prevent eluent in the cell from out-gassing
due to abrupt volume changes between the small inner diameter of the connecting tube and the
relatively larger volume of the cell. Out-gassing creates bubbles in the cell and disrupts detector
responsiveness. Back pressure coils help to prevent gases from out-gassing and prevents
formation of bubbles in the detector cell. For example, carbonate eluent is suppressed to
carbonic acid which is CO2gas in equilibrium with DI water; CO2gas can come out of solution
if adequate pressure is not applied. The above out-gassing can trap bubbles in the cell causing
high noise. Therefore Dionex recommends addition of 30-40 psi of backpressure for most
applications.
Back pressure coil components are located in the detector Ship Kits as part of the Gas Separator
Waste Tube Assembly/Back Pressure Coils Kit, P/N 045825. For 4 mm systems, locate
assembly P/N 045877. For 2 mm systems, the backpressure coils are available in the microbore
tubing kit, P/N 052324. For 2 mm systems, locate assembly P/N 045878. Alternatively, lengths
and diameters of tubing necessary for proper back pressure are given in Table 2, “Coils for
Dionex CRS 500 Back Pressure Requirements.” Adjust the tubing length to achieve a
backpressure of approximately 40 psi.
If back pressure coils become damaged or plugged, they may cause irreversible damage to
the suppressor.
Assemble as follows:
A. Slip PEEK liquid line bolts and ferrules onto the ends of the tubing. Refer to Table 2,
“Coils for Dionex CRS 500 Back Pressure Requirements,” and determine the correct
number of coils required for your application based on the eluent flow rate.
B. After assembly of the coils, see Figure 8, “Configuration of the External Chemical
Mode with the Dionex CRS 500 Suppressor,” for the proper placement of the
assembled coils and couplers after the detector cell and before the waste container.
NOTE
!
CAUTION
!

2– Installation
Thermo Scientific
Product Manual for Dionex CRS 500 Suppressor
Page 20 of 40
031727-07
Table 2 Coils for Dionex CRS 500 Back Pressure Requirements
Dionex
CRS III
Type
Flow Rate
I.D. of
Tubing
Appropriate
Length of
Each Coil
Number
of Coils
4 mm
0.5–1.5 ml/min
0.010" (Black)
2.5 feet
2
4 mm
1.5–3.0 ml/min
0.010" (Black)
2.5 feet
1
2 mm
0.12–0.25 ml/min
0.005" (Red)
6.0 inches
2
2 mm
0.25–0.75 ml/min
0.005" (Red)
6.0 inches
1
The above recommended length of tubing may vary depending on the I.D. of the tubing.
The correct amount of back pressure for optimum operation is 40 psi.
Back pressure over 150 psi after the Dionex CRS 500 can cause irreversible damage!
CAUTION
!