Chromatography Forum

Hi, all -

My Agilent injector is giving very poor reproducibility, ~8% RSD for 5 injections. I figure I have a leaky seal, or some basic maintenance that needs to happen.

The problem is that I haven't performed this on an Agilent before, and we are using old equipment without the manuals. (Although, if I remember correctly, Agilent manuals weren't very helpful anyway.) Could anyone give me step-by-step guidance on what to replace, and how?

It's a 1313A. We have spare needles and needle seat.

Any advice welcomed!

Eric

Try this link. It is to the Agilent site and has videos for maintenance of various instruments:

http://www.chem.agilent.com/en-US/Suppo ... ideos.aspx

Lcguy1

Thanks, lcguy1! I'll try it first thing tomorrow. If I can find an extra rotor seal lying around!

E

The problem is that I haven't performed this on an Agilent before, and we are using old equipment without the manuals. (Although, if I remember correctly, Agilent manuals weren't very helpful anyway.) Could anyone give me step-by-step guidance on what to replace, and how?

It's a 1313A. We have spare needles and needle seat.

Here's what I'd do (I'd do all because you state it's old):
LC has good link for Agilent help, this stuff is not too difficult.
(1) Needle
(2) Needle seat
(3) Autosampler rotor seal (I'd leave the connections on, and just remove the three allen-head screws).
(4) Meter piston and its seal, same part number for both as for the 1100 pump. This is what meters the microliters to be injected.

I've also seen leaks in the coiled loop of the autosampler, welds go bad.

Hi, Consumer Products Guy -

It appears from the videos that I don't need any special tools, just an allen wrench and open-end wrench. Is this true? Also - should I replace the gasket ("isolation seal")? Do you know if this comes with the rotor seal when I order it?

Also - there are no videos for metering piston and seal for a 1313A. Is it similar to how it's performed on the 1367A?

Thanks, CPG!

Eric

You shouldn't need to replace the isolation seal, and it's separate. For the metering seal, look at pump and piston/piston seal videos.

Hi Eric,
if the rotor seal looks O.K. examine and clean the stator face (the white disk) and the injector piston.
But the poor RSD may come from the leak between the needle and the needle seat. Do a pressure test to check leaks in the system. If you see crystalls on the seat around the needle, probably there is the leak.
My recommendation for leak test(s):
Do the first for the pump only. Close the system with a blank nut at the pump, at the purge valve. Do not care about the test description, and do not go on if the pump pressure test fails. If pass do a second closing with the blank nut the end of the solvent heater at the column compartment (as the description says). If the second pressure test fails check the capillary connections. If find any leaks at the capillaries repeat the test again. Now -after two tests- if there is a leak at the needle seat, it is visible now (use a lamp!).
If there is a leak the best if you change the both, needle and seat.
But sometimes a needle vertical reposition is enough. Do the same like the needle replaceing procedure. Folow the maintenance videos.
If the needle is up, do not forget to clean the seat!
Before you press 'END' in maintenance window do not forget to put the front cover back!
If you finish repeat the pressure test again.
Before you start it do an injector reset, because the inj. remains in bypass position after maintenance positions.
I hope this coud help.
Attila01

I hope this coud help.
Attila01

Thanks, Hun !!!

(couldn't resist)