Chromatography Forum

Hi,

Just got a 7890A with FID and NPD. 1st time ever using NPD.

If I don't have a column connected to the NPD, are there any special temperature/flow conditions I need to keep it at to maintain the life of the bead? The tech said something about not letting the bead get exposed to the atmosphere during the installation, but that seems like I would have to keep a column (He flow) connected at all times...is this correct?

Many thanks to anyone who has experience and can offer some insight! I just don't want to start out by messing up my new NPD!

I think, you should plug both the inlet and the outlet of the detector, then set the makeup gas (He or N2) just very little (say 1ml/min) only to maintain the He (or N2) environment inside the detector.

Old chromatographers like me had a special way of solving problems like this. Judging by posts on the forum it is no longer taught at any level.

The name that we gave to this procedure was "Reading the Instructions".

You will find them on a CD that came with your new instrument, or on the Agilent website.

Peter

Hey jerkoff, I read the instructions provided by Agilent. There was no specific mention of this in the NPD users guide. I'm looking for practical advice from experienced users.

Take your holier-than-thou attitude elsewhere if you don't have anything valuable to add.

Maybe instead of insulting you should really start to read the manual (as Peter suggested). If you are too lazy to look for it click here http://www.chem.agilent.com/Library/use ... 90318b.pdf
http://www.chem.agilent.com/Library/use ... 90317a.pdf

But you will find a lot of info on Agilent's website...

I have the manual, and I read the manual, and it says nothing about the initial question I asked. Why is this so hard for you guys to understand?

Does anybody have any practical adivce? Do I have to leave a column installed in the detector at all times?

Well, maybe I am a little simple minded, but if the manual doesn't cover the topic, I tend to assume it isn't terribly important. Then I try to apply logic to the problem, during operation there is a flow of air at elevated temperature, so I suspect the bead is unlikely to be ruined by exposure to air at room temperature during installation. If you read the instructions in the link posted above, you will see that the caution is against the bead touching a solid surface, not exposure to air.

There are many posts on the forum about how to keep a system in peak condition, and the recommendation is usually to either keep a column connected and have a low flow through the detector, or to cap off the detector and keep a low flow of makeup through the detector.

Good morning g-star

You are a beginner in chromatography you say, and that probably means that you will have quite a few problems to solve where advice from experienced users will be useful. You will find that the advice will be more useful if you supply as much relevent information as you can; in this case "I have read the instructions and I cannot find the information that I need" would have saved me the trouble of posting, and of ruffling your feathers.

You will also find that experienced users are more inclined to be helpful if you maintain the standards of polite discussion that are required on this forum, lapsing into puerile insults like an ill-mannered teenager is not the way that we do things around here; another set of instructions that you need to read and pay attention to is the Rules of the House for this forum.

Peter