Dionex ASI 100 leaks after syringe exchange

[bunnahabhain]

Dears

I have massive trouble with my ASI 100 autosampler. The syringe was leaking, therefore I had to exchange it. I ordered the replacement and it came with Teflon seals that look similar to what I destroyed while removing with pliers .
So I screwed it in, and still leaks from the thread where the syringe is screwed in.



So I thought my fingers were too weak and continued screwing with pliers. I checked if it was tight every 1/4 turn, but it remained leaky until the glass barrel popped out of the metal top of the syringe.

There is one thing that looked strange to me from the very beginning: The Teflon seal looks like it was too long, see photo:



Is this what went wrong? I don't have other seals than these, they came with the syringe and there are plenty of them in our drawers, but it just doesn't look right.
Is there anybody out there having experience on how to fit a syringe into the ASI 100? Any help much appreciated, I don't want to waste more syringes...

Regards
Jörg

[Alfred88]

Dear bunnahabhain.
We have the same Dionex Summit HPLC for many years, and I have serviced and keep it running until now.
Our problem: The Summit has been made obsolete by Thermo/Dionex. They want people to buy the Vanquish or Ultimate HPLC.

Here are my suggestions for your ASI-100:
1/ Order the 250uL syringe from Hamilton ($70). If you need the part #, call them or post here.
2/ Remove the old white top seal using a needle-like pick tool. You push the pick tool deep enough then rotate/twist the seal to get it out.
3/ Put in the new seal.
4/ Install the new syringe. Do not add any extra ring inside syringe. Do not use pliers (or use only for the top metal part! not the glass part) to tighten the syringe.

BTW, do you also have Agilent HPLC? What brand do you like more?

Best.
Alfred

[bunnahabhain]

Dear Alfred

This is exactly the procedure I followed. Problem is, that I screw in the syringe fingertight (is only pssible when gripping the glass part, at least with my fingers). When I start using pliers, of course I only touch the metal part. But the pressure that is built up from the top seal to the class part becomes too big without properly sealing the glass against Teflon seal or Teflon seal against the metal block, and the glass is pushed out of the metal part of the syringe. Meanwhile I destroyed three syringes. Two-component glue is not suuitable to repair this, unfortunately.
BTW: The photo in the first post shows the seal without the additional ring shipped with the syringe (the one you need when you want to use it as, well, syringe )

We also have Agilent (1100) systems and one Ultimate 3400. I never had to change syringe with these systems, so no direct comparison possible with this respect. Generally speaking, all have their advantages and disadvantages. When it comes to the autosampler, I must admit that I like the concept of the ASI-100 best. Minimum movements and easy access to all vial positions. The gripper arm of the 1100 is a ridiculously complicated system, and I have seen on more than onece that the fingers do not catch the vial correctly. The Ultimate autosampler is a PITA if you want to access vials: Go to the menu using an unnecessary magnet pen, then click through the menu until you are finally where you want to be. Ease of use was a clear victim of design in this case. Best needle wash of the three systems, though.

Regarding performance, all are OK for our needs, of course precision is a bit better with the Ultimate system when it comes to low injection volumes. I guess this is normal ageing of the older systems, or technical advancement in general.

Regards
Jörg

[bunnahabhain]

Update

The syringe and seals were not the problem. Not the capillary on the right side of the syringe in the photo above: This was blocked and caused the liquid to find its way around the seal. Things are so easy sometimes...

Jörg

[Alfred88]

HI.
So this problem is resolved. Good.
Just to remember to change the rotor seal if needed.

I have also used the Agilent 1100/1200 HPLC. The design of the autosampler is a total failure, and I have written about it on this forum (Why you have to expend time/energy/wear out to transport vials). The software also failed the current Part 11 requirements. Also, the front faces are all blank; one cannot tell if a system is in use by looking at the hardware. (Note: I invite Agilent engineers to prove me wrong!).

We also have the Ultimate 3000. The "magic pen" is seldom used for hot menu points. The system is very reliable.

Alfred

[kevingrove]

Hello, I wondered if as "they came with the syringe and there are plenty of them in our drawers" you would mind me requesting some of these seals as I can't seem to get hold of any, I don't mind sending a donation if possible...

[bunnahabhain]

Depends on where you are located Send me your contact data to joerg.johannes@laus.de and I will send you a pack of 3.
You can also order from www.techlab.de, look for item no. AST 101.708; this is a pack of syringe with two of these seals.