SPME Manual Injection - QP2010 Ultra

Discussions about GC-MS, LC-MS, LC-FTIR, and other "coupled" analytical techniques.

5 posts Page 1 of 1
Hi everyone, my first post here so go easy on me :)

I am the main user of the GC MS in our institution, and have been asked by a colleague to assist in getting a method established for SPME sampling. I have all the requisite items now, and have set up the machine (Shimadzu QP2010 Ultra, with AOC20i autosampler) with the correct liners, etc.

My issue now is with the method - how do I manually inject the fibre for thermal desorption? Clearly I need to remove the AOC20i, but how can I overide the method so that it doesn't try to autoinject, only to fail because the autoinjector is not on the port? How do I know when time 'zero' on the chromatogram commences? I am using the supplied GC Solutions software (not living up to its name at the moment!)

Any help would be very gladly received. Shimadzu tech support here in Australia is a little thin on the ground, and their main tech is back in Japan at the moment.

Cheers

Mark.
PhD candidate.
Just thought I would report that I have managed to figure it out, so I thought I would post it in case someone else has the same issue.

The key point was to remove the Autosampler from the Instrument>Settings screen. Once this is done, the autosampler tab dissappears and I can manually inject. I am injecting on cue of the software when the status changes to Run.

After some playing with the method, I think I am heading in the right direction.

Cheers,

Mark.
Hi,

Thanks for posting your solution to this. I am trying to do a manual injection on the same system. Do you inject before or after pressing start in the data acquisition window?
Just saw this thread.

I'm mostly an Agilent guy when it comes to GC-MS(with a bit of Varian and Finnigan experience) but at the same time some of the basic principles are the same.

First of all, I do SPME only occasionally with a manual Supelco injector. Varians start automatically when you bottom them out(one of the few redeeming qualities of Varian GCs :) ). On HP/Agilents, I hit "start" as soon as I deploy the fiber, which I do as soon as the injector bottoms out. I don't know how much manual injection experience you have, but this is consistent with how I was taught and do manual injections-basically pushing through the septum, hitting the plunger, and pressing start in one coordinated two-handed motion. For this reason, I like GCs with a start button on the front panel-and this is also why I generally do SPME on an HP 5890 rather than the newer 7820.

In any case, as a few other thoughts-I find that the Supelco injectors tear up septa like crazy. I use pre-drilled septa tightened appropriately, but I might still only get 10 injections from one(compared to 200 easily with either a conical autosampler needle or bevel manual syringe). Even changing it that often, I often pull the liner out and physically dump out the shed particles of septa. For that reason, this past week I've been using a Duckbill septum and it keeps trucking along. I'm using something that's not on the market yet, but the best known septum of this type is the Merlin MicroSeal.
benhutcherson wrote:
Just saw this thread.

I'm mostly an Agilent guy when it comes to GC-MS(with a bit of Varian and Finnigan experience) but at the same time some of the basic principles are the same.

First of all, I do SPME only occasionally with a manual Supelco injector. Varians start automatically when you bottom them out(one of the few redeeming qualities of Varian GCs :) ). On HP/Agilents, I hit "start" as soon as I deploy the fiber, which I do as soon as the injector bottoms out. I don't know how much manual injection experience you have, but this is consistent with how I was taught and do manual injections-basically pushing through the septum, hitting the plunger, and pressing start in one coordinated two-handed motion. For this reason, I like GCs with a start button on the front panel-and this is also why I generally do SPME on an HP 5890 rather than the newer 7820.

In any case, as a few other thoughts-I find that the Supelco injectors tear up septa like crazy. I use pre-drilled septa tightened appropriately, but I might still only get 10 injections from one(compared to 200 easily with either a conical autosampler needle or bevel manual syringe). Even changing it that often, I often pull the liner out and physically dump out the shed particles of septa. For that reason, this past week I've been using a Duckbill septum and it keeps trucking along. I'm using something that's not on the market yet, but the best known septum of this type is the Merlin MicroSeal.


I will second the thought on using a Merlin Microseal. I haven't used them for SPME but just for regular autosampler use they last a very long time. Recently on the instruments using normal septa I get sudden leaks with less than 100 injections, and it seems that one injection it is fine, then the next a massive leak. I am trying to move away from them, and not sure why they fail so quickly now, because years ago ( 20+) I could easily get 300 injections from a septa before it leaked.

As for when to hit start, the most important thing is to do it the same way each time and what gives you the most reproducible retention times. Consistency is what is needed the most.
The past is there to guide us into the future, not to dwell in.
5 posts Page 1 of 1

Who is online

In total there are 11 users online :: 1 registered, 0 hidden and 10 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: Google [Bot] and 10 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