HPLC degasser issue

Discussions about HPLC, CE, TLC, SFC, and other "liquid phase" separation techniques.

21 posts Page 2 of 2
Context is important. There are many incompatibilities. These "special" degassers have chemical and mechanical properties which if not taken into account, may result in failure. It is not fair to lump them all together. We have spent decades studying them and working with the manufacturers and clients to make solid recommendations based on real world use.

The manufacturer of the degassing tubing and chamber states that sodium azide is INcompatible with the specific Tefon membranes used in those degassers (we do not know the specifics, just that they warn against using any of them with sodium azide as their testing showed damage). They do not specify any % or amts.
Solvents such as THF, Chloroform etc are well documented to not be chemically compatible with PEEK parts (Agilent does in fact address this warning in other parts of their own manuals and warns against using any of those solvents where PEEK parts are found. Not just the degasser, as PEEK parts may be found in the injector flow path and seals). Hexane and Heptane are known solvents which can weaken and damage the degassing membranes resulting in internal leaks or condensation unless special methods are taken (we have special versions of the degassing chambers from the manufacturer that claim compatibility with those solvents, but the std ones that Agilent provides in that degasser are not compatible). *This has to do with the properties of the thin tubing used. As you can see, this is a complex topic and you can not generalize suggestions when discussing vacuum degassers. There are many types available and each has it own limitations and applications so it is best to discuss based on application at the time of training.

As noted before, if anyone has questions or concerns about having their degasser serviced or which applications may or may not be safe, please contact Chiralizer Services for more information.
Take the cover off the degasser module and Swap the chambers. They are all the same, ex: if degasser B is compromised, swap with D
If your gradient method runs on A and B you can also just change the method to utilize C and D
I’ve seen some chamberS internals turn pink due to high TFA usage.
The system vacuum pump lasts 5-10 years. The Japanese degasser modules fail the most ( serial number starts with Jp)
Sorry, but the info provided by BostonFSE is not relevant and inaccurate. The OP's degasser is an integrated degasser, not a standalone unit (As already noted). Totally different design not made to be serviced by end-users. Swapping chamber positions is not advisable in any degasser and likely to contaminate a chamber that may not have been contaminated. Please ignore this advice. *To test for ruptured or leaking vacuum chamber, please plug the vacuum line that goes to the suspect chamber. No additional contamination will occur using that method.

The HPLC vacuum degasser modules are designed to last up to 5 years (under ideal conditions, rare today). A lack of maintenance and/or use with incompatible chemicals often results in damage during this time. When they are older than 5 years, they are often being used in a contaminated and/or broken state (no errors are generated when they are contaminated so the flow path may be contaminated for some time until the module is professionally serviced). *We know this because we have provided professional service for these modules to most of the manufacturers and end-users for 25 years. We regularly "re-service" degasser modules for our clients that were previously "serviced" by third party companies which are fully contaminated inside and/or do not achieve or meet operating specifications at all. The degassing tubing and membranes used in the more modern degasser designs are very delicate and have many limitations in their use. Most, not all, can not be used with strong acids, strong bases, THF, DCM, chloroform, hexane/heptane and so on, as previously noted (vs many older versions which had improved compatibility with some of these chemicals).

Comments like "The Japanese degasser modules fail the most" is completely false and without any context. We have professionally serviced thousands of HPLC degasser modules over the past decades (and HPLC, LC-MS systems). Please do not add misinformation to this topic. Our job should be to promote accurate and useful information that makes people aware of the pros and cons of using HPLC vacuum degassers. The convenience of having a simple black-box that you just plug into the mains for power and ignore for many years comes with many trade-offs, trade-offs that many users do not receive any training on so need to be aware of the limitations and required maintenance.
Hi all,
We have 10 HPLC's of agilent.(1260 quarternary, 1260 binary and 1290 quarternary)
Almost all the systems are more than 5 years old.
Recently in last three months our two degassor units went off ( Chamber leakage observed,) and both are 1260 quartenary.
We are not able to understand why this one is happened or what we did wrong.
one thing is that in some instrument we worked on Normal phase also (Hexane/IPA/DEA) but i am not sure about this is the reason or somthing we did wrong.
if any one can help me to understand the reason help me. please
cksoni; A clean, working HPLC vacuum degasser is critical to maintain stable baselines and low sensitivity.

The vacuum degas modules are designed to last between 2 to 5 years before requiring professional service (depends on model and type as chemical compatibility and design vary a lot between models). All of them internally break down with use (not a 'design' flaw, like everything else, they wear out and must be serviced or replaced, as needed). For example, the internal vacuum tubing should be replaced at least every five years with ultra-high purity vacuum tubing. The vacuum pumps are normal wear/tear items so have a limited lifetime. The vacuum chambers wear out over time, from mis-use (i.e. leaving them with air inside, or not using them all), use with incompatible chemicals, rupture, pervaporation... It is a good idea to have each degasser included in a special SOP which schedules them for routine diagnostic testing every few years to maintain them. Manufacturers do not service them (well some do, but the same cost as replacing them). Just as routine maintenance should be performed on your HPLC pump, sampler or detectors, the vacuum degasser service, which is more specialized in service, should be scheduled too.

Note: Some vacuum degasser modules are not compatible with solvents such as THF, chloroform, Hexane etc. If used with incompatible solvents or additives, the degasser may be internally damaged (plus your HPLC's flow path may be contaminated from their use, including your column) Some are easily damaged by applying pressure to the vacuum channels (designed to have liquid drawn from them only, never pushed through them). Because the degasser operates as a 'black box' (you can not see what is going on inside), clients tend to ignore them until they are broken, which is often too late.

If you would like to investigate having your degasser(s) professionally serviced, please contact our company, Chiralizer Services, LLC http://www.chiralizer.com/hplc-degasser-repair.html to learn about professional servicing of your degasser. Optionally, you can contact the original manufacturer to purchase a new or refurbished module too. In an case, be sure to have them professionally serviced as continued use may result in flow path contamination OR, if you work in a regulated environment, having an out-of-compliance HPLC system subjecting data and methods to be questioned.
Hello @multidimensional
Do you know of any reseller of your degasser replacement kits for h-class QSM in Germany? I can only find resellers of original waters parts.
Thanks in advance.
Jörg
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