Agilent 1260 Leak Help!

[Karen01]

First, as I said before, while I have a lot of HPLC experience, it was all on Water's equipment and I am unfamiliar with Agilent HPLC equipment and trying to figure things out as I go along, so all suggestions are welcome


Awhile back I was having a problem getting a baseline on the RI detector on the system. It seemed to go away when I tightened up the pre-column holder... Then I did not use the system for about a week. Last Thursday when I started it up again, the RI was drifting downward very significantly with a steep slope even after equilibrating for several hours... I noticed a leak at the pre-column inlet (though the TCC was not detecting a leak) and thought maybe that was the problem.

So figuring that the ferrule was not seating right, I changed the line from the heat exchnager to pre-column using new nuts and ferrules.

Now I keep getting leak errors from the TCC module, but for the life of me I can't see any leaks visually at it or using the kimwipe test on all the fittings in the flow path.

I really need to get this up and running ASAP, so I would greatly appreciate suggestions.

Thanks,
- Karen

[MSCHemist]

Run the leak test. It is in the diagnostics section of chemstation. Basically you block the flow in various places with a solid nut and run isopropanol following the instructions. That should tell you if their is a leak upstream of the nut. You can run it at various points to narrow it down.

Is the running pressure less than normal? Is it fluctuating rapidly? Could be a faulty leak sensor also. make sure the mobile phase completely evaporated from the last leak. Put some methanol or ethanol on the sensor and blot it up with a kimwipe. There is also a rotor seal in the column module that can go bad. You might also try shutting everything down rebooting the computer and starting it up again.

[Karen01]

Run the leak test. It is in the diagnostics section of chemstation. Basically you block the flow in various places with a solid nut and run isopropanol following the instructions.

I did run it... with Water as that is what the pump manual said... But I see now that the on-line help says to use IPA!

The results I got with water said indeterminate and to run the valve test... But as the instrument is only 2 months old (and allI've run through the system is water and ACN ), I figured that was unlikely.

Is the running pressure less than normal? Is it fluctuating rapidly?

Pressure was normal.

Could be a faulty leak sensor also. make sure the mobile phase completely evaporated from the last leak. Put some methanol or ethanol on the sensor and blot it up with a kimwipe.

I don't know where the sensor is, but liquid on the sensor must have been the issue. Today I started up the system and I'm not getting the error! Must have dried up overnight!

Well at least I'm learning this hardware.

Thanks,
- Karen

[Consumer Products Guy]

Karen - on Agilent thermostatted column compartments (1050, 1100, 1200, 1290 - haven't seen 1260) the leak sensor is in the middle, bottom, somewhat obscured. If there's a leak causing a shut-down, we use cotton-tipped applicators to soak up any liquid, then let it dry 10 minutes.

There's a heat exchanger on each sise, sometimes an accessory column switching valve, and, or course, all column connections. If a ferrule won't seat well, install new tubing or use fittings with PEEK ferrules.

When you do the "KimWipe test" do you leave a KimWipe under the fitting for several minutes while it's pumping? Also, you know this, but for others: pressure is way higher at inlet side of column than on the exit side.