Page Optimizing Performance Optimizing Performance How to optimize the micro vacuum degasser to achieve best chromatographic results When the micro vacuum degasser is switched on, the control circuit turns on the vacuum pump which generates a partial vacuum in the vacuum container.
When to Use a Micro Vacuum Degasser? All values are set in the factory according to the vacuum level. Depending on the vacuum sensor batch variations this will result in different voltage readings. Regardless of the readings of the various stages no adjustment should be performed on the degasser electronics. Page 28 Optimizing Performance Operation Modes of the Micro Vacuum Degasser If the vacuum level of normal operation mode two cannot be achieved within 8 minutes the instrument turns into error mode.
Page 30 Optimizing Performance Operational Hints for the Micro Vacuum Degasser 3 Disconnect solvent outlet tube of the channel that is supposed to be primed from your pump. Page Prevent Blocking Of Solvent Filters Optimizing Performance Prevent Blocking of Solvent Filters Prevent Blocking of Solvent Filters Contaminated solvents or algae growth in the solvent bottle will reduce the lifetime of the solvent filter and will influence the performance of the pump.
This is especially true for aqueous solvents or phosphate buffers pH 4 to 7. The following suggestions will prolong lifetime of the solvent filter and will maintain the performance of the pump.
Page Troubleshooting Troubleshooting Errors, their probable cause, and the action required to correct them Page Status Indicators Status Indicators Two status lamps are located on the front of the micro vacuum degasser. The left lamp indicates the power supply status, the right lamp indicates the micro vacuum degasser status.
When the lamp is illuminated green , the power is ON. Instrument Status Indicator The instrument status indicator indicates one of three possible instrument conditions. The micro vacuum degasser itself will not be able to generate any error messages in the system logbook of the Agilent Series.
The following pages describe hardware symptoms which help you to isolate the cause of a hardware failure. Page All Lamps Are Off Troubleshooting All Lamps are Off All Lamps are Off If all other modules in the system are on power switch lamp is green and are recognized by the connected user interface module parameters can be set, module-specific screens appear, and so on , then do the following to determine the problem with the micro vacuum degasser: Ensure the power cable is connected to the degasser, and the power cable is connected to line power.
If a test meter is available, check the resistance of each fuse. A good fuse shows a low resistance approximately 0 Ohm.
If the vacuum cannot be reached, or is lost faster than expected during operation, the micro vacuum degasser will be forced into an error state. Check the operation of the vacuum pump. A pressure reading above mV indicates that one of the pump chambers is contaminated or defective. Results A pressure reading below mV indicates a good working vacuum chamber 1. To prevent personal injury, the power cable must be removed from the micro vacuum degasser before opening the cover.
Do not connect the power cable to the micro vacuum degasser while the covers are removed. Cleaning should be done with a soft cloth slightly dampened with water or a solution of water and a mild detergent. Do not use an excessively damp cloth that liquid can drip into the micro vacuum degasser. In order to prevent damage, always use an ESD strap supplied with the standard accessory kit when handling electronic boards and components.
Using the ESD Strap 1 Unwrap the first two folds of the band and wrap the exposed adhesive side firmly around your wrist.
Please observe appropriate safety procedures for example, goggles, safety gloves and protective clothing as described in the material handling and safety data sheet by the solvent vendor, especially when toxic or hazardous solvents are used. If your micro vacuum degasser was shipped in cold weather, leave it in its box and allow it to warm slowly to room temperature to avoid condensation.
The Agilent Series vacuum degasser has been tested for evaporation of solvents into the atmosphere by an independent institute with approved methods. Evaporation of these solvents into the atmosphere when operating the degasser was below the limits of detection. Unpacking the Micro Vacuum Degasser Damaged Packaging Upon receipt of your micro vacuum degasser, inspect the shipping containers for any signs of damage.
If the containers or cushioning material are damaged, save them until the contents have been checked for completeness and the micro vacuum degasser has been mechanically and electrically checked. If the shipping container or cushioning material is damaged, notify the carrier and save the shipping material for the carriers inspection.
Delivery Checklist Ensure all parts and materials have been delivered with the micro vacuum degasser. The delivery checklist is shown below. Optimizing the Stack Configuration If your micro vacuum degasser is part of a system, you can ensure optimum performance by limiting the configuration of the system stack to the following configuration.
This configuration optimizes the system flow path, ensuring minimum delay volume from point of solvent mixing to head of column and dead volume from point of injection to detector outlet. Figure 1. Locate bench space Provide power connections Unpack the vacuum degasser module 1 Place the micro vacuum degasser on the bench.
The interface cable remote cable is a one way connection to send a not-ready signal from the degasser to the other modules to shut down the whole system after an error condition of the degasser. The Agilent Series micro vacuum degasser is an exception. The micro vacuum degasser can be connected via the APG remote connector to the other modules of the stack. The AUX output allows to monitor the vacuum pressure in the degasser chamber. An Agilent Series control module can be connected to the CAN bus at any of the modules in the system except for the degasser.
The Agilent ChemStation can be connected to the system through one GPIB cable at any of the modules except for the degasser , preferably at the detector.
For more information about connecting the control module or Agilent ChemStation refer to the respective user manual. The power switch stays pressed in and a green indicator lamp in the power switch is on when the micro vacuum degasser is turned on. When the line power switch stands out and the green light is off, the micro vacuum degasser is turned off. Solvent cabinet including solvent bottles filled with solvent and bottle head assemblies Micro Vacuum degasser Solvent outlet tubes Syringe with adapter.
Install the micro vacuum degasser 1 Place solvent cabinet with the bottle s on top of the micro vacuum degasser. When working on capillary or tube fittings solvents may leak out. Please observe appropriate safety procedures for example, goggles, safety gloves and protective clothing as described in the material handling and safety data sheet supplied by the solvent vendor, especially when toxic or hazardous solvents are used.
Use the mounting tool shown in Figure 6 to fix the tube screw. Fix the tubes in the clips of the micro vacuum degasser. Figure 6. Atmospheric gases can diffuse through the tubing and dissolve in the mobile phase solvents. For best chromatographic results, keep the length of tubing between the micro vacuum degasser and your pump as short as possible.
Drain any remaining solvents from the degassing channels before transporting the micro vacuum degasser. Continue to draw solvent into syringe until the solvent channel is completely empty. Optimizing Performance How to optimize the micro vacuum degasser to achieve best chromatographic results. Introduction to the Micro Vacuum Degasser The micro vacuum degasser comprises a 4-channel vacuum container, including 4 micro structured membranes, and a vacuum pump.
When the micro vacuum degasser is switched on, the control circuit turns on the vacuum pump which generates a partial vacuum in the vacuum container. The pressure is measured by a pressure sensor. The micro vacuum degasser maintains the partial vacuum by turning on and off the vacuum pump depending on the signal from the pressure sensor. The LC pump draws the solvents from their bottles through the special tubular plastic membranes of the vacuum container. As the solvents pass through the vacuum tubes any dissolved gas in the solvents permeates through the membranes into the vacuum container.
The solvents will be almost completely degassed when leaving the outlets of the micro vacuum degasser. Figure 8. When to Use a Micro Vacuum Degasser?
Generally a degasser should be used when negative effects due to dissolved gas in the mobile phase exceed the limits that are acceptable for the user. This may result in a high ripple or high standard deviations of peak retention times and peak areas especially at low flow rates. Operation Modes of the Micro Vacuum Degasser The micro vacuum degasser allows various operation modes. In this mode the vacuum level is below Torr.
The voltage readings given for the various modes are approximate values. All values are set in the factory according to the vacuum level. Depending on the vacuum sensor batch variations this will result in different voltage readings. Regardless of the readings of the various stages no adjustment should be performed on the degasser electronics. Normal Operation Mode 1 When the degasser is turned on, the vacuum pump runs and is connected to ambient through the solenoid valve.
The solenoid valve activates about 15 seconds after turning on the degasser you can hear it click. The vacuum pump then begins to pull a vacuum on the vacuum chamber. The voltage measurements begin to decrease rapidly.
The normal operation mode vacuum level Torr is achieved when the DC voltage measures approximately to mV. After achieving the normal operation mode vacuum level, the solenoid valve turns off.
The vacuum pump continues to run for a few seconds, then it turns off. When the DC voltage measurement rises back to approximately to mV, the turn on process begins again. If the vacuum level of normal operation mode one cannot be achieved within 8 minutes the instrument turns into normal operation mode 2. Normal Operation Mode 2 Timing Mode Under certain operational conditions large amount of dissolved gas in mobile phase, high flow rates the Torr trigger level for operation mode 1 cannot be reached.
The vacuum degasser automatically turns into operation mode 2. Normal operation mode 2 is a fixed timing mode. Every 2 minutes the degasser is turned on for 30 seconds. This assures a pressure level in the range from to Torr.
The pressure signal measured with the auxiliary cable is in the range between to mV. If the vacuum level of normal operation mode two cannot be achieved within 8 minutes the instrument turns into error mode. When turning on the vacuum degasser the vacuum pump will run continuously.
If the vacuum level of normal operation mode 2 cannot be achieved within 8 minutes the instrument turns into error mode. When to use Continuous Mode In continuous mode the vacuum pump runs continuously thus generating the highest degassing efficiency of the degasser. Error Mode The error level for the vacuum degasser is Torr approximately mV. This level cannot be achieved when there is a failure in the degasser for example, leaks, etc.
When the error level is exceeded the yellow status indicator lamp is turned on and the vacuum pump runs continuously. If the degasser cannot reach one of the normal operation modes within 8 minutes the status indicator turns red and the vacuum pump is turned off.
Operational Hints for the Micro Vacuum Degasser Priming the Degasser The micro micro vacuum degasser can be primed either by drawing solvent through the degasser with a syringe or by pumping with the connected pump. When opening capillary or tube fittings solvents may leak out. Priming with a Syringe Before using a new degasser or new tubings for the first time: 1 Prime all tubings with at least 5 ml of iso-propanol no matter whether the channels will be used with organic mobile phase or with water.
If you are changing to a solvent that is immiscible with the solvent currently in the tubing continue as follows: 2 Replace the current solvent with iso-propanol, if current solvent is organic or with water, if current solvent is an inorganic buffer or contains salt. When priming the micro vacuum degasser with a syringe the solvent is drawn through the degasser tubes very quickly.
The solvent at the degasser outlet will therefore not be fully degassed. Pump for approximately 5 minutes with your selected flow rate before starting any application. This will allow the micro vacuum degasser to properly degas the solvent in the degasser tubes. The pump should never be used for priming empty tubings never let the pump run dry. Use the syringe to draw enough solvent for completely filling the tubings to the pump inlet before continuing to prime with the pump.
Priming with the Pump When the pumping system has been turned off for a certain time for example, overnight oxygen will rediffuse into the solvent channels between the micro vacuum degasser and the pump. Solvents containing volatile ingredients will slightly lose these, if left in the degasser without flow for a prolonged period of time. Therefore priming of the micro vacuum degasser and the pumping system is required before starting an application.
Solvent Information Always filter solvents through 0. Prevent Blocking of Solvent Filters Contaminated solvents or algae growth in the solvent bottle will reduce the lifetime of the solvent filter and will influence the performance of the pump. This is especially true for aqueous solvents or phosphate buffers pH 4 to 7.
The following suggestions will prolong lifetime of the solvent filter and will maintain the performance of the pump. Checking the Solvent Filters The solvent filters are on the low-pressure side of the pumping system.
A blocked filter therefore does not affect the pressure readings of the pump. The pressure readings cannot be used to identify blocked filters. If the solvent cabinet is placed on top of the micro vacuum degasser the filter condition can be checked in the following way: Remove the tubing at the inlet port of the micro vacuum degasser. If the filter is in good condition the solvent will freely drip out of the solvent tube due to hydrostatic pressure. If the solvent filter is partly blocked no solvent or only very little solvent will drip out of the solvent tube.
Two status lamps are located on the front of the micro vacuum degasser. The left lamp indicates the power supply status, the right lamp indicates the micro vacuum degasser status.
An agilent series hplc system agilent, san jose, ca, usa , consisting of a ga binary pump, a i manual injector and a ga degasser, was used for chromatographic analyses.
An agilent series hplc system agilent technologies, san jose, ca, usa consisting of a ga binary pump, a i manual injector, and a ga degasser were used for chromatographic. The manual injection for each sample was 20 l. We have agilent series hplc with vacuum degasser, binary pump, autosampler, thermostated column compartment and mwd.
Chromatographic results suggest that the presence of these flavanol mixtures could facilitate the formation of precipitates to the detriment of soluble aggregates. Packaging should be the same as what is found in a retail store, unless the item was packaged by the manufacturer in non-retail packaging, such as an unprinted box or plastic bag.
However, like in other cultured cells, ct-like activity reached 1, mg on average, while tumor weight from groups inhibition could be detected only by cell-based activity assay but treated with 1. To disconnect the vacuum degasser from line, unplug the power cord.
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