Dionex ASE 350

Discussions about sample preparation: extraction, cleanup, derivatization, etc.

12 posts Page 1 of 1
Does anyone has Dionex ASE 350 in their labs?
In normal operation, the sample cell is filled with solvent and placed inside the oven. When the fill pressure of 10.34 MPa (1500 psi) is reached, the pump is turned off. The cell (and solvent) are heated at the extraction temperature for a set time. When the pressure reaches 11.72 MPa (1700 psi) during the set time, the static valve opens to relieve pressure by dispensing some of the solvent out of the cell and into the collection vessel. A small amount of solvent is pumped each time the static valve opens to compensate the solvent out of the cell. It so happens that the static valve only opens one or two times for most of the organic solvents. However, when DCM (or a mixture of DCM with other solvents) is used, we find that the pressure shortly reaches 1700psi, causing the static valve to open every 5-10 seconds during the static extraction. This significiantly increases the solvent volume and also causes variation of heated solvent/sample contact time.
Did anyone come across this before? Is it inherent for ASE350 when DCM is used? Any remedial action? We don't have such problem in ASE200 with DCM.
Thanks for your advice in advance.
One option would be to contact tech support at Thermo. They support the ASE now.
Don Shelly
LGC Standards
The cells are definitely not leaking? DCM tends to get out where other solvents dont, and a leaking cell (at least int the 200) is the most common cause of the cycling pressure symptom you seem to be seeing. As you said, DCM doesnt inherently cause problems in a 200 (we have one still going strong after 15 years) although it does leak a lot easier than toluene, for example. I'd be surprised if it caused inherent problems with a 350.
A small leak is hard to detect in the ASE cell. I am not quite sure whether it is the cell problem because ASE350 cell is different than ASE200. The engineer still can't figure out the problem. He said maybe the pressure sensor is so sensitive c.f. that used in ASE200 which therefore we don't see such problem in previous model. Btw, is there any way to tighten the cell ?
Hello chhubert,

How old is your ASE 350 (what is the serial number)? We may have a solution for this issue. Please ask your local field service engineer to contact Thermo Fisher Scientific's factory IC/SP Technical Support group for more details (they should have our contact info).

By the way, please do not try to tighten the cells with any tools!

Best regards,

John Guajardo
Sr. Technical Support Specialist, Dionex Products
Thermo Fisher Scientific
Best regards,

John Guajardo
Product Manager, IC Columns
Thermo Fisher Scientific
Thanks John. Our ASE 350 is brand new. The service engineer has been struggling for weeks trying to solve the problem. He did say he asked the manufacturer already but in vain. Anyway, I'd try to ask the service engineer to do so, if he really does....
chhubert, I'm sorry to hear that. What region are you in? Please email me your field service rep's name and I will reach out to them.

Best regards,

John Guajardo (john.guajardo@thermofisher.com)
Sr. Technical Support Specialist, Dionex Products
Thermo Fisher Scientific
Best regards,

John Guajardo
Product Manager, IC Columns
Thermo Fisher Scientific
Thanks again. I have passed your contact to our local supplier and I think he would contact you shortly . Hope things will go well soon.
Hello:

We are looking to buy an ASE 350. Is it possible to share your experience with this system? Thank you very much fro your time.
With the AE200 you can vary the temperature. This is not an option with the ASE 350 which is set on 100 °C. DCM has a low boiling point (around 40°C) and therefore the cell will easily be over pressurised and needs to discharge more often. You maybe can compensate it with the pump calibration volume.
WE have an ASE200 and ASE350. Never had a problem with DCM, only with MeOH. ASE350 has a standardized pressure of 1500 psi, when you heat the DCM it will overpressurize and need to actuate the relief valve. Are you using 100% DCM?
Hello,

I would like to know if anybody in the forum is using NaOH for extractions with ASE 350. Thanks
12 posts Page 1 of 1

Who is online

In total there are 2 users online :: 0 registered, 0 hidden and 2 guests (based on users active over the past 5 minutes)
Most users ever online was 599 on Tue Sep 18, 2018 9:27 am

Users browsing this forum: No registered users and 2 guests

Latest Blog Posts from Separation Science

Separation Science offers free learning from the experts covering methods, applications, webinars, eSeminars, videos, tutorials for users of liquid chromatography, gas chromatography, mass spectrometry, sample preparation and related analytical techniques.

Subscribe to our eNewsletter with daily, weekly or monthly updates: Food, Environmental, (Bio)Pharmaceutical, Bioclinical, Liquid Chromatography, Gas Chromatography and Mass Spectrometry.

Liquid Chromatography

Gas Chromatography

Mass Spectrometry