Eicom ENO-30, Руководство пользователя

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13. Troubleshooting
In the case that your analysis can not be performed by the ENO-30, and that troubles persist
after reading this document, please refer to this chapter.
Please inject a standard sample to find
the cause of trouble. If this chapter is not helpful, please contact Eicom.
13-1. Pump Problems
This unit will explain how to determine if the liquid delivery method is normal or not. All delivery
problems will appear on the chromatogram chart, usually as a longer retention time than
expected. First, check that there are no slow leaks at the tubing connections (around manual
injector, valve in autosampler, column inlet/outlet, etc).
13-2. Checking the Flow Rate
For the Carrier pump, set the flow to 500 µL/min and collect liquid at the waste line outlet for 1
minute with
only the Carrier pump running. If you use a small microcentrifuge tube, you can
estimate quickly whether it’s 500 µL or more like 250 µL. If it is only 250, then you have a
bubble.
For the Reactor pump, disconnect the tubing where it enters the three way joint by the reaction
loop. Collect a sample here for 1 minute by setting the pump to 500 µL/min and running only the
Reactor pump. If it’s close to 250 µL, there is a bubble.
13-4. Removing Air Bubbles
Air bubbles are the main problem encountered with the pump unit. Air-bubbles are sometimes
generated in the Carrier and Reactor Pumps. As long as air exists inside a pump, the pump will
not work as liquid delivery pump. To prevent this air generation, an online degasser is included.
So air generation will be very rare. However, if air is trapped in one of the pump heads during
washing or at start up, the following symptoms may occur.

lower than expected pressure?

lower than the expected volume at the waste line outlet based on the flow rate setting?

longer than expected retention times for the peaks?

frequent error 4?

smaller than expected standard peak heights, especially nitrite?
To clear the trapped air bubbles, there are several strategies.
1) The simplest method is to connect a syringe at the purge valve, open the valve and aspirate
to remove the bubble. Close the valve and check symptoms again. Repeat a couple of times.
2) If that doesn’t work, do the same things again except this time pull the syringe quickly and