Precolumn derivatization on Agilent 1100 - Chemstation B.02

[aproulx78]

Hi all,

I'm trying to get my precolumn derivatization injector program to work for my Agilent 1100 with Chemstation B.02.01 and every time it seems I am not drawing any sample. The procedure runs as expected, vials pick up as anticipated, injects without any problem. But every time, the signal comes back as if there was no sample drawn, just the derivatizing agent signal.

Do any of you have examples of precolumn derivatization injector programs that work?

Thanks!
Amy Proulx
Research Fellow - Agriculture Canada

[lmh]

I use Agilent's 1100 autosampler to add spikes to samples on occasion, and have had success.
(1) Watch the instrument go through the injection sequence and make sure it really has picked up both vials; or look and check there are holes in the septa indicating that something happened!
(2) I don't know how your program works, but do check that you haven't exceeded the maximum volumes that the metering device can handle. To be honest, your best bet is probably to ask Agilent to check the program for you. I've found them very helpful: they like to feel that their equipment is being used successfully, as in the long run, this sells more equipment!
(3) You might want to ensure you've got a mixing step to make sure the reagent and the sample are mixed, not merely stored side by side in a needle for a few seconds before being injected.

[aproulx78]

Thanks for your answer. I spent some time fiddling around with my injector program yesterday, and after changing my draw speed from default to max for sample, buffer and derivatizing agent vials, everything started working. I already had a mix step, repeated 5x, and a hold step too.

Sometimes I think there is just no explaining Chemstation! We had the problem you mentioned, no sample drawn from completely random samples about 10% of the time, or wrong vial picked up, on a previous version of Chemstation (A.10). Everyone was sure I was imagining it, and just doing poor sample prep, until someone from another lab came to run samples in our facility. As well as I think I know my HPLC, and Chemstation, I believe my HPLC has a mind of its own sometimes. Problem was fixed with the software/firmware upgrade.

Cheers,
Amy
Research Fellow, Agriculture Canada