Chromatography Forum

Am in the process of converting 6890N w FID from He carrier to H2 using a Packard 9200 H2 generator, only when the connection is made, the generator stops generating. Works fine if its plumbed for the FID only so I know the generator is working. Only thing I can think of is that the generator is an older unit and can't handle the flow requirement, it thinks there is a leak and shuts off?????

Did you remember to set the 6890 inlet for H2? Also Agilent recommends putting an external flow restrictor on the carrier gas line inlet in case of an EPC leak or malfunction so there is never a dangerous flow of H2.

Hi vickig,

I think the Packard 9200 H2 generator is perfectly fine for a single GC's carrier and fuel gas for an FID:

https://www.sigmaaldrich.com/content/da ... t/7982.pdf

I concur with MSCHemist's recommendation above--and add that you may want to plumb the carrier stream with stainless steel. If you've got copper in there now, okay, but keep an eye on that tubing's condition over time as hydrogen can be a bit corrosive.

I am assuming that you are working with a capillary column and capillary inlet. It is not only the carrier flow that you need to take into account but also the split flow if you are running in split mode. A column flow of 2ml minute and a split ratio of 100 requires over 200ml/minute of hydrogen at the capillary inlet.

Gasman

Thank you all!

You can also buy inline stainless gas flow snubbers from your gas supplier. I'm using bottle gas to run my 6890 with hydrogen carrier. I concur about plumbing with new cleaned stainless line for the hydrogen.

I witnessed the situation where Packard H2 generator killed 6890 EPC with alkali solution tossed to H2 line.

I think - better use electrolyzer or cylinders (from outside the building).

No matter if H2 lines are copper or stainless steel.

AFAIK - the EPC has color-coded restrictors (pneumo-resistance) which have to be changed appropriate to used carrier gas.

please explain what you mean by "alkali solution tossed to H2 line"

You can ignore that comment by Antonk. That hydrogen generator does not use a caustic solution.

A couple of general notes: I'd never use a hydrogen tank for carrier without a flow restrictor, but one really isn't necessary for contemporary hydrogen generators.

I've used the Parker version of that H2 generator. Of all the H2 generators I've used it was by for the worse. Always expensive problems with the cell. We finally gave up and retired it. As GasMan correctly points out, it's easy exceed the capacity of that H2 generator if you're doing high-split capillary work. We did a number of times. Try to bring your method up with greatly reduced spit.