1. Manuals
  2. Brands
  3. Dionex Manuals
  4. Laboratory Equipment
  5. DX-120
  6. Operator's manual

Dionex DX-120 Operator's Manual

Ion chromatograph
Hide thumbs
Table of Contents

Advertisement

Quick Links

DX-120 ION CHROMATOGRAPH
OPERATOR'S MANUAL
© 1998 Dionex Corporation
Document No. 031183
Revision 03
September 1998

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the DX-120 and is the answer not in the manual?

Questions and answers

Related Manuals for Dionex DX-120

Summary of Contents for Dionex DX-120

  • Page 1 DX-120 ION CHROMATOGRAPH OPERATOR’S MANUAL © 1998 Dionex Corporation Document No. 031183 Revision 03 September 1998...
  • Page 2 Dionex Corporation, 1228 Titan Way, Sunnyvale, California 94088-3603 U.S.A.

  • Page 3: Table Of Contents

    Contents 1 • Introduction About This Manual ....1.1.1 Typefaces and Conventions ..1.1.2 Safety Messages and Notes ..1.1.3 Symbols .
  • Page 4 DX-120 Operator’s Manual TTL Control ..... 2-23 2.5.1 Injection Valve/Remote Start Control . . 2-23 2.5.2 Recorder Range Control ..
  • Page 5 Contents Pump Loses Prime ....Pump Does Not Start ....No Flow .
  • Page 6 DX-120 Operator’s Manual A • Specifications A.1 Electrical ..... . . A.2 Environmental/Physical ....
  • Page 7 Contents B.6 Connections to Chromatography Components . . B-10 B.6.1 Backpressure Requirements ..B-12 B.6.2 Self-Regenerating Suppressor (SRS) Installation ....B-13 B.6.3 Column Installation .
  • Page 8 DX-120 Operator’s Manual C.4 Using DIALOG to Create a Method ..C.4.1 Time Functions ....C.4.2 Creating a Method ... . .
  • Page 9 These components are mounted on the inside of the DX-120 door. The DX-120 can be controlled locally, using the front panel keypad and display, or remotely, from a PeakNet workstation. The PeakNet workstation consists of a computer with a Dionex DX-LAN™...

  • Page 10: About This Manual

    Lists the DX-120 specifications and installation Appendix A site requirements. Specifications Describes how to install the DX-120. Appendix B Installation Describes how to program a Dionex 4400 or Appendix C 4600 integrator for automated control of the Integrator DX-120. Programming Describes conductivity detection and its Appendix D applications.

  • Page 11: Typefaces And Conventions

    1 • Introduction 1.1.1 Typefaces and Conventions • Capitalized bold type indicates a front panel button. For example: Press to turn on the pump. Pump • Upper-case bold type indicates information displayed on the front panel screen. For example: displays when a leak occurs. LEAK ALARM •...

  • Page 12: Safety Messages And Notes

    Council Directives 73/23/EEC and 89/336/EEC, EN 61010-1:1993 (safety), EN 50082-1:1992 (susceptibility), and EN 55011:1991 (emissions). The TUV/CE and GS safety label on the DX-120 attests to compliance with these standards. The DX-120 is designed for ion chromatography applications and should not be used for any other purpose. If there is a question regarding appropriate usage, contact Dionex before proceeding.

  • Page 13: Symbols

    Power supply is on Power supply is off 1.2 Related Manuals During installation and operation of the DX-120, you may need to refer to one or more of the following manuals for information about other components or instruments in the system.
  • Page 14 DX-120 Operator’s Manual • PeakNet Software User’s Guide (Document No. 034914) • Installing the PeakNet System (Document No. 034941) Doc. 031183-03 9/98...

  • Page 15: Operating Features

    2 • Description 2.1 Operating Features Figures 2-1 and 2-2 illustrate the main operating features of the DX-120. Figure 2-1. DX-120 Operating Features (Exterior) Doc. 031183-03 9/98...
  • Page 16 DX-120 Operator’s Manual Figure 2-2. DX-120 Operating Features (Interior) Doc. 031183-03 9/98...

  • Page 17: Front Control Panel

    The control panel liquid crystal display (LCD) shows status information and alarm conditions. Press a button in the group labeled DISPLAY to determine the type of status information shown. The remaining buttons control DX-120 operation. Figure 2-3. DX-120 Control Panel Button...
  • Page 18 Turns the gas pressure to the eluent reservoirs on and off. When on, the LED on the button is illuminated. This button is disabled when the DX-120 is in Remote mode (see Local/Remote below). Turns the pump flow on and off. When on, the LED on the button is illuminated.
  • Page 19 - sends a TTL signal indicating that an injection has occurred After 1 minute, the valve automatically returns to the Load position (SW1-1). This button is disabled when the DX-120 is in Remote mode. COLUMN SELECTION The COLUMN SELECTION buttons are active in the dual-column configuration only.

  • Page 20: Pump

    0.5 to 4.5 mL/min. Eluent Save Mode If the DX-120 is idle (i.e., no control panel buttons have been pressed and no PeakNet commands have been received) for 90 minutes, the pump flow automatically decreases to 1/20th of its current flow rate and the SRS cycles on and off.

  • Page 21: Eluent Reservoirs

    (e.g., water and methanol). With non-aqueous components, glass reservoirs are recommended. The single-column DX-120 includes one 2-liter plastic reservoir (P/N 044129). The dual-column DX-120 includes two 2-liter plastic reservoirs. The following additional reservoirs are available from Dionex: •...

  • Page 22: Component Panel

    Chromatography components are mounted on the inside front door. Figure 2-4 shows the single-column component panel layout. Figure 2-5 shows the dual-column layout. The DX-120 is equipped with a Rheodyne injection valve (see Section 2.1.6). The following additional components must be ordered separately: •...
  • Page 23 2 • Description C D M -3 C ell Injection Valve G uard C olum n A nalytical C olum n Figure 2-4. Single-Column Component Panel Layout NOTE A DS4 Detection Stabilizer can be installed instead of the CDM-3 cell. Doc.
  • Page 24 DX-120 Operator’s Manual Figure 2-5. Dual-Column Component Panel Layout NOTE A CDM-3 cell can be installed instead of the DS4 Detection Stabilizer. 2-10 Doc. 031183-03 9/98...

  • Page 25: Rheodyne Injection Valve

    2 • Description 2.1.6 Rheodyne Injection Valve The Rheodyne injection valve has two operating positions: Load and Inject. In the Load position, sample is loaded into the sample loop, where it is held until injection. In the Inject position, sample is swept to the column for analysis. Eluent flows through one of two paths, depending on the valve position: •...

  • Page 26: Detector Cells

    DX-120 Operator’s Manual 2.1.7 Detector Cells The DX-120 accommodates two detector cell models. The DX-120 standard cell (CDM-3; P/N 050776) is used for applications that do not require the enhanced baseline stability gained through thermal stabilization. For increased thermal stabilization in high-sensitivity applications, use a DX-120 high-performance cell with heater (DS4 Detection Stabilizer;...

  • Page 27: Ds4 Detection Stabilizer

    2 • Description Temperature Control and Compensation Temperature directly affects the conductivity of a solution. For example, laboratory heating and air conditioning systems can cause a regular slow cycling in the baseline. This, in turn, can affect the reproducibility of an analysis. The higher the conductivity, the more pronounced the effect.
  • Page 28 DS4 heats it to a user-selected temperature from 30 °C to 45 °C (SW3-4, 5, 6, 7). A sensor near the heat exchanger outlet senses the eluent temperature. The DX-120 circuitry compares this temperature with the selected temperature and adjusts the heat input in real time to hold the temperature within a few millidegrees.

  • Page 29: Dual-Column Configuration Features

    2 • Description 2.2 Dual-Column Configuration Features The dual-column configuration has two operating modes: • Column select mode allows switching of flow from one column set to the other. • Eluent select mode allows switching of flow from one eluent to the other (the column set is not switched).

  • Page 30: Column Select Mode

    DX-120 Operator’s Manual 2.2.1 Column Select Mode In column select mode, you can switch the flow path from one column set to the other by pressing Column A Column or by sending a command from PeakNet. Figure 2-8 illustrates the sequence of events when you switch from column set A to column set B.
  • Page 31 2 • Description 1. In Step 1, eluent A is flowing to column set A. 2. In Step 2, the following occurs: • A command is received to switch to column B. • The eluent selection valve switches and eluent B begins flowing to the injection valve.

  • Page 32: Eluent Select Mode

    In this mode, the column switching valve is disabled. The selected column set remains at what it was when the DX-120 was switched to eluent select mode. The LED on the button...

  • Page 33: Fluid Schematics

    2 • Description 2.3 Fluid Schematics Figure 2-10 shows the flow path through a single-column DX-120 Ion Chromatograph. 0.03 - 0.07 MPa (5 - 10 psi) Figure 2-10. DX-120 Flow Schematic: Single-Column 2-19 Doc. 031183-03 9/98...
  • Page 34 DX-120 Operator’s Manual Figure 2-11 shows the flow path through a dual-column DX-120 Ion Chromatograph in column select mode. 0.03 - 0.07 MPa (5 - 10 psi) Figure 2-11. DX-120 Flow Schematic: Dual-Column System Column Select Mode 2-20 Doc. 031183-03 9/98...
  • Page 35 2 • Description Figure 2-11 shows the flow path through a dual-column DX-120 Ion Chromatograph in eluent select mode. 0.03 - 0.07 MPa (5 - 10 psi) Figure 2-12. DX-120 Flow Schematic: Dual-Column System Eluent Select Mode (Column Set A Active) 2-21 Doc.

  • Page 36: Control Modes

    DX-120 Operator’s Manual 2.4 Control Modes The DX-120 has two control modes: Local and Remote. Select Local for control from the DX-120 front control panel and select Remote for control from a PeakNet workstation. To change the mode, press . The selected mode is Local/Remote shown in the lower right-hand corner of the display.

  • Page 37: Ttl Control

    • Offset the background conductivity • Change the recorder range by 10x • Turn the pump flow on and off TTL control is available when the DX-120 is in either Local or Remote mode. Refer to Section B.7 for TTL connection instructions.
  • Page 38 DX-120 Operator’s Manual If the Range DIP switch is set to 1000 µS, sending the 10X Range TTL input signal will have no effect. The table below summarizes the relationship between the 10X Range TTL input and the Range DIP switch.

  • Page 39: Operation And Maintenance

    3 • Operation and Maintenance 3.1 Preparing Eluents 3.1.1 Degassing Eluents Dionex strongly recommends degassing all eluents and storing them in reservoirs pressurized with filtered inert gas (see Section 3.1.3). This helps prevent bubbles (resulting from eluent outgassing) from forming in the pump and the detector cell.

  • Page 40: Filtering Eluents

    2. Press to turn on the gas pressure to the Eluent Pressure eluent reservoir(s). A regulator inside the DX-120 regulates the pressure to between 0.03 and 0.07 MPa (5 to 10 psi). Never pressurize the reservoirs above 0.07 MPa (10 psi). If using glass reservoirs, inspect them periodically for scratches or cracks.

  • Page 41: Preparing Samples

    Before injection, pretreat samples that may contain high concentrations of interfering substances by putting them through Dionex OnGuard™ cartridges. Refer to the Installation and Troubleshooting Guide for OnGuard Cartridges (Document No. 032943) for instructions. Doc. 031183-03 9/98...

  • Page 42: Diluting

    DX-120 Operator’s Manual 3.2.3 Diluting Because the concentrations of ionic species in different samples can vary widely from sample to sample, no single dilution factor can be recommended for all samples of one type. In some cases (for example, many water samples) concentrations are so low that dilution is not necessary.

  • Page 43: Operating

    3 • Operation and Maintenance 3.3 Operating 3.3.1 Starting Up 1. Press the power switch below the DX-120 front control panel (see Figure 2-2) to turn on the system power. Microprocessor code revision levels are displayed briefly on the screen, and then the offset conductivity reading is displayed.
  • Page 44 CELL TEMP HI flashes when the DS4 is above operating temperature. Figure 3-1 shows the display after all start-up steps are complete and the DX-120 is ready for a sample injection. Figure 3-1. Display after Start-Up Completed NOTE If the DX-120 receives no input for 90 minutes, the pump flow is reduced to 1/20th of its current rate and the SRS cycles on and off (SW1-2).

  • Page 45: Injecting The Sample

    Load position. 3. Fill the syringe with a calibration standard or sample. 4. Insert the syringe into the port on the front of the DX-120 (see Figure 2-2). 5. Overfill the sample loop with several sample loop volumes.
  • Page 46 DX-120 Operator’s Manual 4. Press to switch the injection valve to Inject. Inject/Load Injection Events By default, the following events occur after injection: • An auto offset occurs (SW3-3), which includes two steps: - The analog output signal is set to zero.

  • Page 47: Using An Integrator

    3.4 Using an Integrator You can connect an integrator, such as the Dionex 4400 or 4600 Integrator, to the DX-120 and use a DIALOG or BASIC program to automate analyses. If you also connect an autosampler, sample loading can also be controlled. See Appendix C for integrator programming examples.

  • Page 48: Optimizing Temperature Compensation

    DX-120 Operator’s Manual 3.6 Optimizing Temperature Compensation The DX-120 built-in temperature compensation stabilizes conductivity readings by correcting for changes in ambient temperature that occur during a run. For more information about temperature control and compensation, see Section 2.1.7. 3.6.1 With a DS4...

  • Page 49: Maintenance

    3.7 Maintenance This section describes routine maintenance procedures that users can perform. All other maintenance procedures must be performed by Dionex personnel. Daily • Check the interior of the main compartment for leaks or spills. Wipe up spills. Isolate and repair leaks (see Section 4.3). Rinse off any dried eluent or reagent with deionized water.
  • Page 50 DX-120 Operator’s Manual 3-12 Doc. 031183-03 9/98...

  • Page 51: Troubleshooting

    To resolve other problems, turn to the section that best describes the operating problem. If you are unable to eliminate a problem, contact Dionex for help. In the U.S., call Dionex Technical Support at 1-800-346-6390. Outside the U.S., call the nearest Dionex office.
  • Page 52 Check all liquid lines and valves for leaks, crimping, or blockage. 2. Make sure the cable connecting the SRS to the DX-120 electronics card is connected (see Figure B-10). 3. Refer to the SRS manual for more troubleshooting information.

  • Page 53: Error Codes

    The error code remains for several seconds, and then the display returns to normal. • E000 Cause: No Moduleware is installed. Moduleware is the DX-120 instrument control microprocessor code. Action: Download a new copy of the Moduleware, if the system includes PeakNet software, or contact Dionex for assistance.

  • Page 54: Liquid Leaks

    Cause: The SRS will not turn on. Either the pump is not on or the suppressor is disconnected. Action: Turn on the pump. Make sure the cable connecting the SRS to the DX-120 electronics card is connected (see Figure B-10). 4.3 Liquid Leaks •...
  • Page 55 Inspect the pressure transducer. If the waste valve is the source of the leak, replace the waste valve O-ring (see Section 5.11). If the leak is from the rear of the transducer, contact Dionex for assistance. • Leaking SRS See the SRS manual for troubleshooting procedures.
  • Page 56 (see Section B.6.1). Follow the steps below to disassemble the DS4 and inspect it for the source of the leak. 1. Turn off the DX-120 power. 2. Disconnect the DS4 cables. 3. Disconnect the DS4 inlet and outlet lines. Do not misplace the ferrule fittings at the end of the tubing (see Figure 4-1).
  • Page 57 4 • Troubleshooting Figure 4-1. DS4 Exploded View Figure 4-2. DS4 Interior Components Doc. 031183-03 9/98...

  • Page 58: Pump Difficult To Prime

    DX-120 Operator’s Manual • Liquid seeping from around cell cables The cell has an internal leak and must be replaced. Contact Dionex for assistance. 4.4 Pump Difficult to Prime • Empty reservoir and/or no eluent connected Connect the pump inlet line to the eluent reservoir. Fill the reservoir.

  • Page 59: Pump Does Not Start

    Check all liquid lines for crimping or blockage. Make sure the ferrule fittings are not overtightened onto tubing. Refer to Installation of Dionex Ferrule Fittings for details. • Plugged or damaged fitting Isolate the faulty fitting by loosening fittings one-by-one until the pressure returns to normal.

  • Page 60: Peak "Ghosting

    DX-120 Operator’s Manual 2. Measure the pump flow rate, using a 10 mL graduated cylinder and stopwatch. Calibrate the flow rate if needed (see Section 5.7). • Clogged column bed supports Replace the bed supports as instructed in the column manual.

  • Page 61: Nonreproducible Peak Height Or Retention Time

    4 • Troubleshooting 4.10 Nonreproducible Peak Height or Retention Time • Column overloading 1. Dilute the sample. 2. Change to a sample loop with a smaller volume (see Section 5.2). • Liquid leaks Locate and eliminate the leaks (see Section 4.3). •...

  • Page 62: Ds4 Temperature Inaccurate

    Remove the cover and inspect the DS4 for broken or shorted wires or for moisture bridging the control thermistor. If a wire is broken or shorted, replace the wire or call Dionex for assistance. If a leak has caused a short, fix the leak (see Section 4.3, “Leaking DS4”) and dry the control sensor.

  • Page 63: No Detector Response

    3. Set SW5-8 to the on position. 4. The conductivity reading on the display should be 25.0 µS. If this is not the case, there may be a problem with the cell electronics. Contact Dionex for assistance. 4-13 Doc. 031183-03 9/98...

  • Page 64: Low Detector Output

    DX-120 Operator’s Manual 4.14 Low Detector Output • Analog output range set too high; although the display indicates a response, no recorder response observed Select the 100 µS range setting (SW4-3, off). • Insufficient sample injected Increase the injection size or concentration. See Section 5.2 for information on changing the sample loop size.

  • Page 65: Noisy Or Drifting Baseline

    • Flow system leak ahead of cell; erratic baseline Check all fittings and liquid lines for leaks. Tighten or, if necessary, replace all liquid line connections. Refer to Installation of Dionex Ferrule Fittings for tightening requirements. • Pump not properly primed Prime the pump (see Section B.5.1).
  • Page 66 DX-120 Operator’s Manual 4-16 Doc. 031183-03 9/98...

  • Page 67: Service

    NOTES Electronics components are not customer-serviceable. Any repairs involving the DX-120 electronics must be performed by Dionex personnel. The CPU card contains a lithium battery. If it is necessary to replace the CPU card, dispose of the used battery according to the manufacturer’s instructions.

  • Page 68: Replacing Tubing And Fittings

    DX-120 Operator’s Manual 5.1 Replacing Tubing and Fittings The DX-120 is plumbed with the tubing and tubing assemblies listed in Table 5-1. Tubing Size and Type Used For 0.125-mm (0.005-in) ID Connection from the pump pulse damper to the (P/N 044221) injection valve 0.25-mm (0.010-in) ID...

  • Page 69: Isolating A Restriction In The Liquid Plumbing

    Follow the steps below to disassemble the DS4 and replace the cell. After replacing the cell, recalibrate it (see Section 5.6). 1. Turn off the DX-120 power. 2. Disconnect the DS4 cables. 3. Disconnect the DS4 inlet and outlet lines. Do not misplace the ferrule fittings at the end of the tubing (see Figure 5-1).
  • Page 70 DX-120 Operator’s Manual 4. Remove the DS4 by lifting it upward and then pulling it away from its mounting location. Place the DS4 on the workbench. 5. Open both latches on the DS4 and carefully lift off the top half of the cover, along with its insulating foam insert, exposing an aluminum box (see Figure 4-1).

  • Page 71: Cleaning Cell Electrodes

    Before latching the cover, make sure the top and bottom inserts meet on all sides. 12. Reconnect the DS4 cables and turn on the DX-120 power. Now, calibrate the cell constant (see Section 5.6).

  • Page 72: Calibrating The Cell Constant

    9. Fill the syringe with 10 mL of deionized water. Inject the water through the cell. 10. Turn on the DX-120 main power switch. Continue to Step 3 of Section 5.6 to calibrate the cell constant. 5.6 Calibrating the Cell Constant Calibrate the cell after installing a new cell or after cleaning the cell electrodes.
  • Page 73 5 • Service 5. Set the temperature compensation to 1.7% (SW5-5, on; SW5-4 and 6, off). This temperature compensation value can be used for most applications. When measuring absolute conductivity, determine the optimal value for each batch of calibration solution (see Section 3.6).

  • Page 74: Calibrating The Pump Flow Rate

    1. Prime the pump (see Section B.5.1). If the pump does not stay primed, proceed to the next step. 2. Turn off the main power switch on the DX-120 and disconnect the main power cord. 3. Disconnect the tube fittings from both the inlet and outlet check valve housings (see Figure 2-2).

  • Page 75: Replacing A Pump Piston Seal

    Flow rates will be unstable and there may be baseline noise. 1. Turn off the main power switch on the DX-120 and disconnect the main power cord. 2. Disconnect the tube fittings from the inlet and outlet check valves.
  • Page 76 DX-120 Operator’s Manual 3. Hold the head firmly against the pump housing, to compensate for the spring loading, and remove the two nuts. Lateral motion when disengaging the head from the piston can break the piston. 4. Slowly release the head, allowing it to separate from the housing.
  • Page 77 5 • Service 9. Press a new back-up seal (P/N 036901) into the O-ring (P/N 035776). If necessary, also replace the O-ring. Then press the O-ring and back-up seal into the back-up washer. 10. Press the back-up washer into the head, followed by the piston guide.

  • Page 78: Replacing A Pump Piston

    Continued leaking from around the pump head after replacing the piston seal indicates a scratched or broken piston. 1. Turn off the main power switch on the DX-120 and disconnect the main power cord. 2. Disconnect the tube fittings from the inlet and outlet check valves.
  • Page 79 5 • Service Figure 5-3. Piston Pump Assembly 10. Slide the spring over the piston, positioning it flush against the spring retainer. 11. Carefully slide the pump head straight onto the alignment rods. Guide the spring over the piston guide. Gently push the piston through the seal.

  • Page 80: Replacing The Pressure Transducer Waste Valve O-Ring

    DX-120 Operator’s Manual Figure 5-4. Pressure Transducer Assembly 5.11 Replacing the Pressure Transducer Waste Valve O- Ring A damaged O-ring causes leakage around the base of the pressure transducer waste valve knob. 1. Press the button to turn off the pump.

  • Page 81: Changing The Main Power Fuses

    3. The holder contains two fuses. Replace both with new fast-blow fuses rated 5 amps 250 Vac (P/N 214339). Dionex recommends replacing both fuses even though only one is open. Fuse Holder...
  • Page 82 DX-120 Operator’s Manual 4. Reinsert the fuse holder into its compartment. The fuse holder is keyed to fit only in its proper orientation. Apply sufficient pressure evenly against the holder to engage the two locks. The holder is flush against the panel when both locks are engaged.

  • Page 83: A.1 Electrical

    A • Specifications A.1 Electrical Main Power Three voltage/frequency configurations (not user-selectable): 100 Vac/50 Hz 115 Vac/60 Hz 230 Vac/50 Hz Fuses Two fast-blow fuses rated 5.0 A (P/N 214339) Analog Output 1 V or 10 V, full-scale output A.2 Environmental/Physical 10 °C to 40 °C (50 °F to 104 °F) Operating Temperature...

  • Page 84: A.3 Control Panel

    DX-120 Operator’s Manual A.3 Control Panel Display Liquid crystal display Buttons 16 front panel buttons for controlling the display and operating functions A.4 Pump Type Single-reciprocating piston with metal-free flow path with PEEK components Operation Constant volume Mode Flow Range 0.5 to 4.5 mL/min...

  • Page 85: A.7 Conductivity Cell

    Cell body: Chemically inert polymer Standard Cell Electrodes: 316 stainless steel Active Volume: 1.25 µL (CDM-3) Maximum Pressure: 2.0 MPa (300 psi) DX-120 High- Note: This cell is included with the DS4 Detection Stabilizer Performance Cell body: PEEK Cell Electrodes: 316 stainless steel Active Volume: 1.0 µL...

  • Page 86: A.10 Delay Volume

    DX-120 Operator’s Manual A.10 Delay Volume System Total <5 mL Doc. 031183-03 9/98...

  • Page 87: B.1 Facility Requirements

    • Make sure the DX-120 installation site meets the power and environmental specifications listed in Appendix A. • Install the DX-120 on a sturdy workbench at a height that ensures convenient viewing of the front panel display and access to the interior.

  • Page 88: B.3 Rear Panel Connections

    DX-120 Operator’s Manual • Set the configuration DIP switches The DX-120 Ship Kit (P/N 050130) contains all items necessary for completing the installation. B.3 Rear Panel Connections B.3.1 Power Connection 1. A label on the DX-120 rear panel indicates the line frequency (50 or 60 Hz) and voltage (100, 115, 230 VAC) for which the system is designed (see Figure B-1).
  • Page 89 B • Installation Figure B-1. DX-120 Rear Panel Doc. 031183-03 9/98...
  • Page 90 DX-120. Use one of the following cables (cables must be ordered separately from the DX-120): • The accessory jumper cable (P/N 960748) is for modules with IEC 320 connectors. • The accessory power adapter cable (P/N 960749) is for modules with NEMA 5-15 connectors (the 3-prong American line cord plug).

  • Page 91: B.3.3 Waste Lines

    B.3.4 Gas Connection Locate the 3-mm (0.062-in) ID tubing (P/N 030089) provided in the DX-120 Ship Kit. Push one end into the gas connector on the rear panel (see Figure B-1). Connect the other end to a source of laboratory-quality helium regulated to between 0.14 and 0.69 MPa (20 and 100 psi).
  • Page 92 For the DX-120 to communicate with PeakNet software, a DX-LAN interface card (P/N 050225) must be installed in the DX-120. If you order a DX-120 with the DX-LAN option, the card is installed at the factory. If you order the DX-LAN at a later time, see Section B.15 for installation...
  • Page 93 DX-LAN cable that is nearest to the ferrite cylinder into the BNC tee on the DX-120 rear panel. 3. If the DX-120 is the last (or only) instrument on the network, cap the unconnected end of the tee with a terminator plug (P/N 921034).

  • Page 94: B.4 Eluent Reservoir Connections

    B.4 Eluent Reservoir Connections 1. Untape the coil of red air tubing from the reservoir tray on the top of the DX-120. Push the end of the tube firmly onto the barbed connector on the eluent reservoir cap assembly. 2. Untape the coil of white eluent tubing from the reservoir tray and screw the tube end-fitting securely into the eluent fitting on the reservoir cap.

  • Page 95: B.5.2 Checking The Pump Flow Rate Calibration

    B • Installation 7. After about 10 seconds, adjust the flow rate to the setting required for the application. 8. Close the pressure transducer waste valve and let the system flush and equilibrate for 10 minutes. B.5.2 Checking the Pump Flow Rate Calibration Check the pump flow rate calibration at installation and whenever you change applications.

  • Page 96: Connections To Chromatography Components

    B.6 Connections to Chromatography Components The DX-120 injection valve, column switching valve (if installed), pump, and cell or DS4 connections are plumbed before shipping. The DX-120 Ship Kit contains tubing assemblies for completing the SRS and column connections. NOTE For shipping purposes, unions are installed between unconnected lines from the cell and valves.
  • Page 97 B • Installation Figure B-5. AutoSuppression Recycle Mode Figure B-6. Nonsuppressed Mode B-11 Doc. 031183-03 9/98...

  • Page 98: B.6.1 Backpressure Requirements

    Degassing creates bubbles in the cell and disrupts detector responsiveness. The DX-120 Ship Kit includes backpressure coils (P/N 045877) for installation after the cell outlet (see Figures B-5 and B-6). The number of coils required depends on the application flow rate and the type of system (see Table B-1).

  • Page 99: B.6.2 Self-Regenerating Suppressor (Srs Installation

    B • Installation B.6.2 Self-Regenerating Suppressor (SRS) Installation NOTE The instructions here do not replace the instructions in the SRS manual. For complete SRS installation instructions, as well as the initial SRS start-up procedure, refer to the SRS manual. The SRS mounts on tabs on the component panel (see Figure B-7).
  • Page 100 DX-120 Operator’s Manual The DX-120 Ship Kit includes certain items required for SRS installation: • SRS gas separator waste tube (P/N 045460) • Backpressure coils for 4 mm SRS (P/N 045877) The SRS plumbing connections depend on whether you are installing one or two column sets.
  • Page 101 B • Installation Dual-Column SRS Installation Figure B-9 shows the connections for a dual-column system. Figure B-9. SRS Connections: Dual-Column DX-120 1. Connect the line from port 4 on the column switching valve to the of SRS A. REGEN INLET 2.
  • Page 102 DX-120 Operator’s Manual Completing the SRS Installation 1. For a single-column system, plug the cable from the SRS into the matching cable extending from the SRS A connector on the electronics card (see Figure B-10). For a dual-column system, also plug the cable from SRS B into the matching cable extending from the SRS B connector.

  • Page 103: B.6.3 Column Installation

    B • Installation B.6.3 Column Installation Before installing the column(s) in the DX-120, refer to the column manual for specialized installation and start-up instructions. Column Setup 1. Before installing the separator column, pump deionized water through the injection valve at 1.0 to 3.0 mL/min for 2 to 5 minutes to clear any air from the liquid lines.
  • Page 104 DX-120 Operator’s Manual 7. Orient the guard column with the outlet facing down and snap the column into its clip. For dual-column systems, snap column A in the back and column B in the front. 8. Orient the separator column with the outlet facing up and snap the column into its clip.

  • Page 105: Ttl Control Connections (Overview)

    (P/N 043275), and ferrules (P/N 043276). B.7 TTL Control Connections (Overview) This section summarizes the functions of the TTL input and output connectors on the DX-120 rear panel (see Figure B-1). For example connections, see Sections B.8.2 and B.9.2. B.7.1 TTL Inputs...

  • Page 106: B.7.2 Ttl Outputs

    DX-120 Operator’s Manual B.7.2 TTL Outputs There are two types of TTL outputs: • The Inject and Pressure Alarm outputs signal when an injection or a pressure alarm occurs. When connected to the TTL inputs of another device, such as an autosampler, these signals can trigger a response in the connected device.

  • Page 107: B.7.3 Ferrite Core Installation On Ttl Output Cables

    B • Installation B.7.3 Ferrite Core Installation on TTL Output Cables An EMI suppression core (P/N 918013) must be installed on any cable or wires used to connect the DX-120 TTL outputs to another instrument. 1. Gather multiple pairs of wires together.

  • Page 108: Autosampler Connections (Optional)

    B.8.2 AS40 Automated Sampler Connections This section describes how to connect an AS40 Automated Sampler to a DX-120 that is connected to a PeakNet workstation. Figure B-14 illustrates the TTL connections. If the DX-120 is connected to an integrator, see Section B.9.2 for the AS40 connections.
  • Page 109 B • Installation 5. Plug the connector into the lower connector TTL Outputs on the DX-120 rear panel. Make sure the red wire connects to the position and the ground wire TTL1 connects to the Ground Figure B-14. AS40 Automated Sampler with PeakNet Connec tions B-23 Doc.

  • Page 110: B.8.3 As3500 Automated Sampler Connections

    DX-120 Operator’s Manual B.8.3 AS3500 Automated Sampler Connections This section describes how to connect an AS3500 Automated Sampler to the DX-120. Figure B-15 illustrates the TTL connections. Figure B-15. AS3500 Automated Sampler TTL Connec tions B-24 Doc. 031183-03 9/98...
  • Page 111 B • Installation 1. Locate the green 5-pin connector (P/N 921273) and the twisted pair of wires (P/N 043598) in the DX-120 Ship Kit. Insert the signal wire from the pair into the last position on the connector. Use a screwdriver to tighten the locking screw.
  • Page 112 Disabling the DX-120 Injection Valve With the above TTL connections, each time the AS3500 sends a remote start output signal to the DX-120 to start a PeakNet run, the DX-120 injection valve automatically switches to the Inject position. If desired, you can disable the DX-120 injection valve.

  • Page 113: Recorder And Integrator Connections

    2. Connect the other end to the 4400 or 4600 Integrator input connectors. Time Functions Automation To use the integrator for timed control of DX-120 and AS40 Automated Sampler functions, install an Automation Cable (P/N 043940), in addition to the Recorder Signal Wire assembly.
  • Page 114 DX-120 Operator’s Manual Figure B-17. Single-Channel Integrator Connections 5. Connect the Automation Cable’s 3-pin green connector, labeled , to the DX-120 upper connector. TTL Output Note: The 50-pin parallel connector, labeled , is not used. B-28 Doc. 031183-03 9/98...

  • Page 115: Configuration Dip Switch Settings

    The DIP switch labeled DIAGNOSTIC TESTS on the rear panel is for service procedures only. Do not change any of its settings unless directed to do so by a Dionex Service representative. For routine operation, all settings are off. B-29...
  • Page 116 DX-120 Operator’s Manual Figure B-18. DIP Switch Settings B-30 Doc. 031183-03 9/98...
  • Page 117 Auto Inject Reset returns to the Load position 60 seconds after it (SW1-1) is switched to the Inject position. When on, if the DX-120 is idle for 90 minutes, Pump Time-out the pump flow is reduced to 1/20th of its (SW1-2) current rate.
  • Page 118 DX-120 Operator’s Manual DIP Switch Function Description Select the type of cell (CDM-3 or DS4) Cell Type installed in the DX-120. Both switches must be (SW4-1, 2) set. Selects the microSiemens output (100 µS or Range 1000 µS) to the recorder of a full-scale detector (SW4-3) response.

  • Page 119: Ds4 Detection Stabilizer Installation

    B • Installation B.11 DS4 Detection Stabilizer Installation If the DS4 is ordered at the same time as the DX-120, it is installed in the DX-120 at the factory. Follow the installation instructions below when you order a DS4 separately.
  • Page 120 (for Nonsuppressed mode). 6. Direct the DS4 spill/overflow tubing to the spill tray at the bottom front of the DX-120. 7. Select a DS4 temperature set point (SW3-4, 5, 6, or 7) (see Figure B-19). Select a temperature at least 5 °C above the highest expected ambient temperature.

  • Page 121: Cell Installation

    B • Installation B.12 CDM-3 Cell Installation If the CDM-3 cell is ordered at the same time as the DX-120, it is installed in the DX-120 at the factory. Follow the installation instructions below when you order a CDM-3 separately.

  • Page 122: Injection Valve Connections

    A 25 µL PEEK sample loop (P/N 042857) is installed between ports 1 and 4. Other sample loop sizes are available. Contact Dionex for information. Figure B-20 shows the connections. Figure B-20. Injection Valve Plumbing B-36 Doc.

  • Page 123: Column Switching Valve Connections

    B • Installation B.14 Column Switching Valve Connections NOTE Refer to the following information if you need to replace any tubing or fittings. The column switching valve for dual-column configurations is plumbed at the factory with the necessary tubing and fittings to connect the valve to the columns, suppressors, injection valve, and cell.

  • Page 124: Dx-Lan Card Installation (Optional)

    For the DX-120 to communicate with PeakNet software, a DX-LAN interface card (P/N 050225) must be installed in the DX-120. If you order a DX-120 with the DX-LAN option, the card is installed at the factory. Follow the installation procedure below if you order a DX-LAN at a later time.
  • Page 125 B • Installation Figure B-22. Removing the Rear Panel 7. Align the BNC connector on the interface card with the opening on the electronics card front plate and insert the interface card connector into the connector on the electronics card (see Figure B-23). The small stainless steel grounding wipers on the BNC connector slide behind the front plate.
  • Page 126 DX-120 Operator’s Manual Figure B-23. Installing the DX-LAN Interface Card 9. Push the electronics card back in and replace the mounting screws. Reconnect the cables that were removed in Step 4. 10. Replace the rear panel and mounting screws. 11. Replace the gas supply line and the TTL connectors.

  • Page 127: C • Integrator Programming

    C • Integrator Programming A Dionex 4400 or 4600 Integrator can collect and integrate data from the DX-120. If you install an Automation Cable (P/N 043940), the integrator can also control the following functions: • Pump on/off • Injection valve position •...

  • Page 128: Setting Offsets

    PT=1000 for 1 V signal). C.2 Setting Offsets The default signal offset for the DX-120 is 10%. This is set with a DIP switch (SW4-4). The recorder offset for the integrator is determined by the OF value. Dionex recommends that you use the DX-120 factory default setting of 10%, and enter for the integrator offset.
  • Page 129 C • Integrator Programming C.4 Using DIALOG to Create a Method Once the application is running on the DX-120, you can create an integrator Method for peak identification, calibration, and reporting. Time Functions, defined in the Method, provide control of DX-120 and AS40 Automated Sampler functions.
  • Page 130 C.4.2 Creating a Method Use DIALOG to create a Method file that includes Time Functions for controlling the operation of the DX-120, the AS40, and the integrator. The Method must also include the Method number, a component table, and a sample table.
  • Page 131 C • Integrator Programming FI = 1 . FE= 1 . PRESS ' ENTER' TO SKI P ENTRY ENABL E BASEL I NE DRAW I NG? [ Y/ N] ( N) STORAGE MENU? [ Y/ N] ( N) FUNCTI ON NUMBER [ 0 - 1 0 ] ( 0 ) FI L E NAME ( ) = "...
  • Page 132 * These are example times; adjust them to meet your application’s requirements. Figure C-2. DX-120 and Integrator Timed Events Example 2. Before running the Method, the T7 Time Function, which controls the pump, must be set to 1 to turn on the pump.
  • Page 133 The BASIC program shown in Figures C-3 and C-4 can be used with a Method program in DIALOG. This program: • Monitors the DX-120 and autosampler to see if they are ready to operate • Monitors the DX-120 for the occurrence of a pressure alarm •...
  • Page 134 REM INTEGRATOR WAITS FOR "SAMPLE READY" FROM AUTOSAMPLER TFN"XD": XD(1)=PEEK#3C1F8 IF XD(1)<3 THEN 162 IF XD(1)=3 THEN 172 REM SAMPLE # INCREMENTED AND INJECTION COMMAND GIVEN Sr=Sr+1 !!"INJECTION SAMPLE";Sr Figure C-3. Integrator BASIC Program for the DX-120 Doc. 031183-03 9/98...
  • Page 135 !"SCHEDULE FINISHED. TYPE ’’RUN’’ TO RESTART." TFN"T7",0 REM PUMP OFF Figure C-4. Integrator BASIC Program for the DX-120 (Continued) Figure C-5 shows the Time Functions for an example DIALOG Method, which runs with the BASIC program. The following main modifications were made to Example A: •...
  • Page 136 DX-120 Operator’s Manual C-10 Doc. 031183-03 9/98...
  • Page 137 D • Conductivity Detection Ions in solution conduct electrical current when voltage is applied between electrodes contacting the solution. Since the magnitude of this current is nearly proportional to the concentration of dissolved ions, conductivity detection is useful for quantifying ionic analytes. D.1 How Conductivity Is Measured The conductivity of a solution is measured by applying an alternating voltage between two electrodes in a conductivity cell.
  • Page 138 DX-120 Operator’s Manual D.2 Conductivity of Solutions According to Kohlraush’s law of independent migration, conductivity is directly proportional to concentration (that is, the conductivity of a dilute solution is the sum of the individual contributions to conductivity of all the ions in the solution multiplied by their concentration).
  • Page 139 D • Conductivity Detection Anions λ Cations λ Acetate Benzoate N(CH Table D-1. Limiting Equivalent Conductivities at 25 ° C Values of λ°i from Table D-1 can be used to calculate conductivities of solutions containing ions. For example, the limiting equivalent conductivity for NaCl at 25 °C is 126.5.
  • Page 140 DX-120 Operator’s Manual to conductivity. For acids and bases, the pK values and the solution pH can be used to calculate the extent of dissociation. D.2.1 Effect of Hydration Sphere and Solvent on Conductivity The limiting equivalent conductivity of an ion, λ...
  • Page 141 D • Conductivity Detection constant, the temperature compensation factor, is expressed in units of %/°C. When operating with a standard cell (without a DS4), setting an accurate temperature compensation factor helps minimize the baseline drift caused by fluctuations in ambient temperature.
  • Page 142 The best solution is to neutralize the eluent in a suppressor. Figure D-1 illustrates the suppression mechanism that occurs inside a Dionex Anion Self-Regenerating Suppressor (ASRS) when NaOH is the eluent for anion-exchange separation. Doc. 031183-03 9/98...
  • Page 143 D • Conductivity Detection Figure D-1. ASRS Suppression Mechanism Analyte anions elute from the column with sodium counterions. Two electrodes, one beside each membrane (on the side opposite the eluent) hydrolyze water to hydrogen and hydroxide ions. Hydrogen ions diffuse across the membrane next to the anode, neutralizing the eluent hydroxide to water, while sodium ions from the eluent diffuse across the other membrane, providing counterions to the hydroxide being...
  • Page 144 For ion chromatography of cations, the suppressor membranes are anion exchange polymers that allow anions to pass freely but exclude cations. The eluent uses dilute acids such as methanesulfonic acid. In the Dionex Cation Self-Regenerating Suppressor (CSRS), methanesulfonate counterions are replaced by hydroxide generated by the electrolysis of water.
  • Page 145 Eluents can be wholly aqueous, containing only water and a strong electrolyte. Or, if an organic solvent-compatible column such as a Dionex OmniPac® or MPIC® column is used, typical reversed-phase solvents such as methanol or acetonitrile can be used. Organic solvents are essential components of ion-pair eluents and provide important selectivity control during ion-exchange separations.
  • Page 146 DX-120 Operator’s Manual hydroxide). Another common eluent is a carbonate/ bicarbonate buffer suppressed to carbonic acid (pKa = 6.2). Carbonate/bicarbonate buffers are easily prepared and are routinely used for isocratic separations of inorganic anions. Other eluents for suppressed anion chromatography include the sodium salts of boric acid (borax, tetraborate, pKa = 9.2)
  • Page 147 (anion-ion pair) or hydrogen ion (cation-ion pair). These are marketed by Dionex as IonSep® reagents. The reagents are purified solutions of quaternary ammonium hydroxide solutions and sulfonic acid solutions.
  • Page 148 DX-120 Operator’s Manual D-12 Doc. 031183-03 9/98...
  • Page 149 E • Glossary Analytical Column Synonymous with Separator Column. Band Spreading The broadening of the sample band as it travels through the column. Band spreading can also occur in the injection valve, detector cell, and interconnecting tubing. Calibration Curve A graph showing detector response in peak height or area versus analyte concentration.
  • Page 150 DX-120 Operator’s Manual Channeling The preferential flow of liquid along more open, less resistant paths through the column packing. This causes Band Spreading. Column Efficiency (N) A measure of the narrowness of analyte bands as they elute from the column. High efficiency is desirable because resolution between closely spaced bands improves with greater efficiency.
  • Page 151 E • Glossary Counterion Ions carrying a charge opposite that of the sample ions (e.g., Na may be the counterion of a Cl analyte. These ions preserve electrical neutrality in solution. % Crosslink Divinylbenzene content in a polystyrene/divinylbenzene (PS-DVB) resin; this contributes to the mechanical strength of the resin and determines chromatographic properties.
  • Page 152 DX-120 Operator’s Manual Packing The material which fills a chromatographic column; usually a resin or silica-based material. Pellicular Resin A resin with a solid, nonporous core coated with a thin layer of more porous material. The exchange sites of pellicular ion exchange resins are located only on the surface layer of the bead.
  • Page 153 E • Glossary Separator Column The column used to perform a chromatographic separations; also called analytical column. Siemens (S) Unit measure of conductance; the reciprocal of the electrical resistance of a solution. Suppressor A device used to minimize eluent conductivity and convert sample species to a common form, thus increasing detection sensitivity.
  • Page 154 DX-120 Operator’s Manual Doc. 031183-03 9/98...
  • Page 155 Index Abnormal retention time, 4-11 Background conductivity Abnormal selectivity, 4-11 Offsetting, 2-5, 3-6 Air particulates, 3-3 Offsetting at injection, 3-8 Alarm Reset button, 2-4 Backpressure Alarms, 4-1 Coils required, B-12 Clearing, 2-4 Requirements, B-12 Enabling/disabling the low pressure, B-31 Troubleshooting, 4-9, 5-3 Enabling/disabling the sound, B-31 Baseline Setting the high pressure alarm limit, B-31...
  • Page 156 DX-120 Operator’s Manual CDM-3 cell, 2-8, 2-12, 3-10, B-32 Effect of hydration sphere and solvent on, D-4 Installation, B-35 Measurement, D-1 Cell constant, 2-12 Of solutions, D-2 Cell leak alarm, 4-1 Offsetting the background, 2-5, 3-6, 3-8 CELL TEMP display, 3-6...
  • Page 157 Index SRS A/B Current, B-31 Suppressing conductivity, 2-13 Test Cell, B-32 EMI suppression, B-7, B-21 Disabling injection valve, 2-23, B-26 End-line filter, 3-2, 4-8, B-8 Display, 2-3 Equilibration time, 3-6, 4-11 DISPLAY buttons, 2-3 Error codes, 4-3 Drifting baseline, 4-15 DS4 Detection Stabilizer, 2-8, 2-13 Benefits, 2-13 Components, 2-13...
  • Page 158 DX-120 Operator’s Manual Humidity Operating specifications, A-1 Kohlraush’s law, D-2 Icons used in manual, 1-4 LCD display, 2-3 Inject mark at injection, 3-8 Leak alarm, 4-1 Inject Mark DIP switch, B-32 Limiting equivalent conductivity values, D-2 Injecting sample, 2-5, 3-7...
  • Page 159 Index Offset conductivity Priming the pump, B-8 Displaying, 2-3 Troubleshooting, 4-8 Offsetting background conductivity, 2-5 Pulse damper Integrator settings, C-2 Specifications, A-2 OnGuard P syringe filter, 3-3 Pump Operating features, 2-1 Calibration, B-9 Operating modes Cleaning check valves, 5-8 TTL input, 2-23 Description, 2-6 Operation Difficult to prime, 4-8...
  • Page 160 DX-120 Operator’s Manual Retention time Signal Troubleshooting, 4-11 Selecting the polarity, B-32 Revisions, Moduleware, BIOS, 3-5 Signal Temperature Compensation Rheodyne valve switches, B-32 see Injection valve, column switching valve Single-column configuration Running, 3-5 Component panel layout, 2-9 Under PeakNet control, 3-9...
  • Page 161 Index Time functions, B-27 Tubing Integrator programming, C-3 Replacing, 5-2 Timed events Integrator method, C-4 Total Cond button, 2-3 Total conductivity Valve Displaying, 2-3 Column switching, 2-8, 2-15 Transition metal cations, D-5 Column switching connections, B-37 Troubleshooting Eluent selection, 2-15 Abnormal retention time, 4-11 Injection valve auto reset, 2-5 Abnormal selectivity, 4-11...
  • Page 162 DX-120 Operator’s Manual Index-8 Doc. 031183-03 9/98...

Table of Contents