Waters e2695 Leaking Syringes

[Terry]

Dear all,

I have two pieces of Waters e2695 HPLC, which was procured in Jan 2011. Before June 2013, we have not changed the injector syringe. In that month (June 2013), I found leakage in the syringe, so I procured new syringes from local Waters office and installed them.

The disaster happened thereafter, new syringe would leak 3-6 months after installation, we have changed 3 syringes until now. Currently, the syringes are leaking with bubbles inside, and RSD for replicate injections of standard fails from time to time.

Our test sample are basically the same as before, that mean our mobile phase and sample have not changed. So I am sure that the root cause of the leaking syringe is not the mobile phase and sample.

One Waters engineer indicates that the seal pack adjustment and compression check (we do this if the RSD is not good or leakage is suspected) may have caused damage to the syringe, which have resulted in leakage.

Do you think injector needle seal pack adjustment and compression check will cause leakage? Can you share with me any other possible causes for leaking syringe?

Thanks in advance,

Terry

[Hollow]

can the compression check be fulfilled?

defective valve 3 could also be a source
We once had a broken capillary from syringe to valve3 (if I remember correctly), but not after such a short time.
Any connection related to the injector should be checked. Starting from V3>V3-inj>inj-V2>V2;loop>V2-V1
(paper for thermoprinter are perfect for detecting small leaks)

is your degasser working properly? What is the vacuum-pressure? (Solvent in syringe is mobile phase, therefore if not degassed, bubbles could be possible). Always purge injector with a column (or restrictor) installed, as sufficient backpressure is needed for proper purge. Maybe do so also before power off.

don't think compression check or seal adj should cause any damage to the system, but I rarely needed seal adj when not doing any maintenance.

[mattmullaney]

Hi Terry,

We are after similar troubles with inability to pass compressibility and subsequent discovery of a malfunctioning syringe with one of our 2695s. To me, it makes no sense that a compression check or a seal pack adjustment would damage a syringe.

These syringes, lately, seem to look a bit different than they used to, I can't put my finger on why--maybe there's epoxy or some other polymer at the end? I could be mis-remembering, too...

Anyway, Hollow's a lot of ideas I concur with on the flow path-V3 and the degasser.

[carlo.annaratone]

I buy the equivalent models from Hamilton and they are excellent quality

[Terry]

can the compression check be fulfilled?

The compression check always passes, weird...

defective valve 3 could also be a source
We once had a broken capillary from syringe to valve3 (if I remember correctly), but not after such a short time.
Any connection related to the injector should be checked. Starting from V3>V3-inj>inj-V2>V2;loop>V2-V1
(paper for thermoprinter are perfect for detecting small leaks)

Tomorrow Waters engineer will come to our site, I will discuss with him regarding the possibility of defective V3

is your degasser working properly? What is the vacuum-pressure? (Solvent in syringe is mobile phase, therefore if not degassed, bubbles could be possible). Always purge injector with a column (or restrictor) installed, as sufficient backpressure is needed for proper purge. Maybe do so also before power off.

I think the degasser is working fine, the vacuum pressure is 0.4 - 0.5 and stable

don't think compression check or seal adj should cause any damage to the system, but I rarely needed seal adj when not doing any maintenance.

[Terry]

I buy the equivalent models from Hamilton and they are excellent quality

Is it possible you share with me the part number of the Hamilton syringe?

Thanks

[Hollow]

weird...

what exactly does "leaking" mean in your case?
is there liquid below the PTFE tip or "just" bubbles in the syringe?

What about the vial closure?
Are they sealing too good when sample is drawn out?
Have you done the inj accuracy test? (gravimetric evaluation of repeated inj of pure water (6x50µL=300mg); but may be adjusted to your needs and capapilities of your balance).
Try with and without septum on the vial.

[remesquaddie]

I have over 25 years of experience on Waters auto samplers, including the WISP series and the current crop of ALLIANCES. Waters uses the very same design syringe on all of these. I have yet to see a problem with a syringe attributed to any other part if the auto samplers. Typically, it has been either the white seal at the top , or the smaller the seal on the plunger needing replacement. If the syringe has been used for a few thousand injections , especially in smaller injections, the glass itself on the inside actually wears away. Hamilton makes a good replaceable syringe.
Hope this helps.

Tony Vella
Hplcworks.net

[mattmullaney]

In our particular case, the leak in the newly-installed syringe (immediately after a PM) was found at the top of the syringe near the glass-metal interface (white seal at top). No bubbles were present in the syringe after repeated injector purges, and (weirdly?) we didn't see any problems with the peak area precision in either the PM work or in one sample run performed after the PM...we did run samples although the compressibility check failed.

Don't know what Terry's symptoms are...perhaps they were similar to ours?

@ Tony--understood. I've not quite the experience you have, but I go back to WISP autosamplers, too...ca. 15 years or so, and heck, the syringe didn't look quite the same to me as they "used to," but I could be mistaken...

[remesquaddie]

The syringe "drive assembly" itself is different to the old Wisp, but not the syringe assembly . A syringe out of an older Wisp with good top seals will work fine on all Alliances. They are usually well built. I have actually tested them at over 500 psi of pressure inside the glass sleeve.
You are welcome to call me if I may be of help. No charge.
858,663.7051

[Terry]

Dear all,

A Waters engineer came to my lab today, she found the V3 valve may be blocked. She told me that if the V3 is blocked, when the syringe moved upward to drain at the completion of injection cycle, the blocked V3 will cause very high back pressure in the syringe, which may cause the leakage of solvent out of the syringe.

she changed that Valve, we are running caffein standard now to see whether it works.

I will let you know the test result.

Regards,

Terry

[Terry]

Dear all,

The syringe works fine, no leakage is observed and the RSD (n=6) for replicate injections of Caffeine is 0.2%. My problem is resolved.

Thank you all for your suggestion.

Regards,

Terry

[Hollow]

thanks for feedback

[mattmullaney]

Terry--my thanks as well for the update and for a piece of knowledge about the health of V3 that can affect the syringe.

In our case V3 didn't appear to be our problem...only the syringe that was new during the PM was swapped out for a new one...our compression checks all passed after that, and we never did have any repeatability problems (I still think that was strange).

[fareedtayyeb]

can the compression check be fulfilled?

defective valve 3 could also be a source
We once had a broken capillary from syringe to valve3 (if I remember correctly), but not after such a short time.
Any connection related to the injector should be checked. Starting from V3>V3-inj>inj-V2>V2;loop>V2-V1
(paper for thermoprinter are perfect for detecting small leaks)

is your degasser working properly? What is the vacuum-pressure? (Solvent in syringe is mobile phase, therefore if not degassed, bubbles could be possible). Always purge injector with a column (or restrictor) installed, as sufficient backpressure is needed for proper purge. Maybe do so also before power off.

don't think compression check or seal adj should cause any damage to the system, but I rarely needed seal adj when not doing any maintenance.

Unique issue in Waters Alliance just like Waters 717 Autoosampler is that the needle at STREAM never leaks once we closes V3,V2 manually and then we checked it at WET and SEAL positions too. This means Valve 1 is okay
However when we test V1 by the procedure it hangs on with Restrictor Missing. with small amount of leak probably Needle Wash solution on vial found.
Seal Pack ADJUST test also hampered with Restrictor Missing message.

Same happens in V2 test . The Waste Valve 3 open upon PURGE mode but again when it performs compressibility test hangs on with restrictor failure error.

I cant believe all my Waters Alliance have same issue and 1 717 autosampler. Something is really wrong.

I noted and did the battery replacement too.

Plz guide

Thanks