H2 generator - min. flow rate for HP5890/FID.

[lespaul]

We're setting up a new lab and we're considering purchasing a H2 generator.

Does anyone know the minimum flow rate required to run a HP5890 w/FID? I've seen they can range from 300mL/min to 2,000ml/L.

From what I've seen here the Ebay generators (China) seem to work quite well...although I would prefer a used Parker Balston if I can find one within budget.

As far as use, we're small startup lab so their will be minimal sample throughput.

[Consumer Products Guy]

Our first hydrogen generator was/is a Parker Balston model capable of 500ml/min. We used that to feed the FIDs of at least four 5890 and 6890 units, as each FID used 40ml/min or less. When we decided to go to hydrogen carrier gas in at least one of the GC units, boss wanted more hydrogen capacity, even though I tried to convince him that these were not all used at once. So we got two Balston Parker units of 850ml/min each, so now have all three plumbed up.

So if you have just one GC, 500ml/min would be PLENTY for both carrier gas (if you wanted) and FID.

[tkubowicz]

Hello

So if you have just one GC, 500ml/min would be PLENTY for both carrier gas (if you wanted) and FID.

One thing to keep in mind is split ratio. If it is really high (50-100) it can be problem to keep H2 flow stable. Of course gas saver can do the trick but I've seen GC with generator (500cc) and from time to time there was problem with some methods.

Regards

Tomasz Kubowicz

[Peter Apps]

Bear in mid that as flow goes up, purity goes down so you need to look at what flow it can deliver at the purity level you need, not what it can crank out when running full blast.

Peter

[lespaul]

Thanks everyone for your help.

I may pickup a Perkin Elmer H2 from a local supply shop - anyone have any experience with these models? I would prefer a Parker Balston

[Jake]

To add to Peter's comment, you don't want to run your H2 at greater than 85-90% for a prolong length of time. So for a method at 1 mL/min column, at 400:1 split, with the generator supplying FID fuel too, you're at capacity. We've run under those conditions in the past, so they're not unheard of. If you're no where near that, you'll be fine. We ran a 3.4 mL/min column, 40:1 split, 40 mL fuel for years on a 500 mL/min generator.