Chromatography Forum

Hi there,

I'm having trouble with my Agilent 1100 HPLC and would much appreciate any input/advice. -- A few days ago, my system started experiencing a shutdown error after running for about 8 minutes. Based on searching through the Agilent manuals, I tracked the issue to the G1379A degasser on my system.

Scavenging through this forum, I came across an older post suggesting that the degasser pump be directly connected to the sensor, to deduce whether the problem might lie within the pump or elsewhere in the system. When I connected the pump-->solenoid-->sensor, the yellow light on the front panel of the system remained illuminated and eventually turned to red/shutdown. I also noticed that the pump ran the entire time before auto-shutdown. It hissed loudly at first and then became more quiet, but--nonetheless--I never noted complete silence of the pump. I also visually inspected all of the hoses and noted no (obvious) flaws; however, it's possible there's one that's too small for me to see.

Based on this information, do you deduce the pump is the most likely source of the problem? And, if so, does anyone know where I could acquire a replacement pump? -- The system is currently equipped with an Iwaki Air Pump (Model: APN-4002-ERC). Are there any other troubleshooting steps you'd recommend before I leap into purchasing a new pump?

Many thanks for any and all advice! Much appreciated!

Hi

Yes it sounds like the pump ( it usually is with the Agilent degassers ). Just to double check recheck and this time as you turn the pump on place you finger on top of the solenoid, you should initially feel a vacuum which will disappear after a few seconds when you hear the click. If you carry on feeling vacuum after the click the solenoid is dead.

There is a posibility it is the sensor, but you are down to the pump and / or sensor now. Pump is cheaper as Agilent wont sell you a sensor on its own...you need to buy the whole power board with it.

Good luck getting spares from Iwaki, I have tried many, many times for that pump type.

Hi LCBob,

THANKS much for your quick reply. I tried your suggestion of placing my finger atop the solenoid while turning it on, and noted that I felt a suction at first, which stopped after <10 seconds. Hence, it's sounding like the pump is the culprit.

Are you aware of any pumps that will work as alternatives to the Iwaki?

Also as a follow up: As I await the arrival of the pump, is there any danger to using the 1100, but leaving the degasser disconnected? I have a filter degasser funnel for degassing solvents -- Any chance that's sufficient during the Agilent degasser downtime? (I'd be running in gradient mode using two channels of my quad pump.)

Thanks again!

A quad pump is a "low pressure mixing" type, which means that dissolved air comes out of solution at the gradient proportioning valve. The worst that can happen is that you lose prime.

If you have a helium tank available and a spare intake frit available, you could jury-rig a sparging system as a temporary measure.

My experience with Agilent 1100 degassers is once they start to fail, other component failures inside the degasser will follow soon. I have found its best to just buy a new aftermarket standalone degasser. For example, after replacing the pump, the solenoid goes out. After the solenoid the vaccum chamber, after that...by this time it would have been cheaper to have purchased a new degasser and spared yourself all of the downtime and headaches.

Carls, Are there any specific aftermarket degassers you recommend?

...My hopes of replacing the pump in my G1379A have met with the difficulty that I'm having a hard time tracking down a suitable replacement pump!

I believe Agilent has a bench repair service for these modules, one set price fixes EVERYTHING. We've used it with an autosampler module.

I use the degassex degasser sold by Phenomenex (my employer) since I can get them from stock. It works fine but it doesn't sit under the solvent cabinet like the Agilent degasser. I dont know of any degassers that have the same shape as the Agilent so this will be true with any replacement.

Hi LCBob,

THANKS much for your quick reply. I tried your suggestion of placing my finger atop the solenoid while turning it on, and noted that I felt a suction at first, which stopped after <10 seconds. Hence, it's sounding like the pump is the culprit.

Are you aware of any pumps that will work as alternatives to the Iwaki?

Also as a follow up: As I await the arrival of the pump, is there any danger to using the 1100, but leaving the degasser disconnected? I have a filter degasser funnel for degassing solvents -- Any chance that's sufficient during the Agilent degasser downtime? (I'd be running in gradient mode using two channels of my quad pump.)

Thanks again!

Sorry not tried any pumps that work as an alternative, interesting idea mind, I will look into this for the future.

You can try without the degasser, if it's a binary, it should be ok. If it's a quat, as Tom said you may have problems, my experience is it tends to work with CH3CN and water mixes but will not with CH3OH:Water mixes.

I've changed out vacuum pumps before on my Agilent degassers. You can order replacement pumps from Agilent. (PN G1322-60000.) Call them for most up to date price. We've done a lot of work on our degassers and have been able to fix everything with new parts. (Most of the time the problem has been cracked tubing, but we've changed out a couple of pumps over the years.) The Agilent manual has a pretty good troubleshooting section to help you determine which part is the problem....you just need a voltmeter. Good luck!

Just had the same problem. After changing the tubing I figured out that it must be the pump.
Unfortunately it was a bit difficult to get a replacement parts for the pump or a hole replacment pump here in spain cause the local agilent support just wanted to sell this "replace repair" service for around 2000€!
After looking a bit aroudn and asking for the specific part number I got the pump from them for around 550€.

It seems really ridiculous to buy a new pump when it's most likely that its membrane is the problem. Which would cost some cents or euros, but you just can't get a replacement part...

especially because these seems to be a commune problem of this degasser...

The troubleshooting section of the degasser manual actually has a very detailed procedure for helping you determine which of your components is the problem. A voltmeter is also very helpful for troubleshooting this as well as just routinely checking the degassers to see if they are getting close to failing.

For replacing cracked or dry tubing, Agilent sells a replacement kit. However, I have used 1/8" i.d. tygon tubing as a substitute without any problems.

If you narrow it down to the pump, it most likely just has some dirt particles inside it. To clean the pump, they recommend disconnecting the tubing (that goes from the pump to the solenoid) at the pump. Turn on the unit and let the pump run for several seconds, then reconnect the tubing. This allows a fast air flow to "blow" out any dirt that may be keeping the "check valves" inside the pump chamber from sealing properly.

If that doesn't work, you can try to service the pump yourself. Once I had purchased a replacement pump (and had nothing to lose) I found that it's really easy to open the side plates on the vacuum pump and clean it myself. Disconnect the pump from the degasser unit, like you would to replace it. Lay the pump on its side then remove the two phillips head screws and lift the plastic faceplate (that the tubing is connected to). Underneath is a small, thin, rectangular rubber membrane with two little flaps that act as the check valves for the vacuum chamber. Take a forceps and carefully lift the membrane free and place on a clean surface. Use a damp swab to clean both sides and be careful not to tear the membrane. You should also wipe off the face plates that the membrane is sandwiched between. Put it back together (it only fits one way and there is a raised post on the inner plate to help line everything up) and re-attach the faceplate. Turn the pump over and do the other side. Reinstall the pump and just as a precaution, perform the above procedure for blowing any lose dirt out of the pump.

For replacing cracked or dry tubing, Agilent sells a replacement kit. However, I have used 1/8" i.d. tygon tubing as a substitute without any problems.

Do you have a part # for the replacement kit of the vacuum tubing, which tends to be the tubing that gets dried and cracked? From my read of the degasser manual (and Agilent's LC maintainance manual), it appears that the only replacement tubing they sell is for the tubing the solvent actually passes through, but I couldn't find anything for the vacuum tubing connected to the pump.

Of course, if tygon has worked fine for you, then maybe I shouldn't worry about buying tubing from Agilent.

The Agilent part number for the vacuum degasser tubing is G1322-60002. It is typically expensive for what you get, but at least you know it will work. This part number isn't listed in the newer manuals so you have to know what you are looking for......

Or get vacuum tubing from the auto parts store or Ace Hardware, I've done this. Priced by the foot typically.