Setting up a HP 5890

[Kashew]

Hi,

I'm working on setting up a HP 5890 in a lab, and I'm having some issues. I have a hydrogen generator and a zero air generator and I need to hook them up to the GC. However, I would like to use hydrogen as both the carrier and the fuel gas, as my procedure calls for it.

Carrier: Hydrogen, 1.1 ml/min, constant flow
Detector: FID 300°C, H2 35 ml/min, Air 350 ml/min

However, there are three inlets for gas. One labelled carrier, one labelled H2(from the person that used it before and I'm assuming is the fuel port for the FID), and the other one I'm guessing is for zero air. How do I go about making this happen?

[Johnny Rod]

Just put a tee piece in the hydrogen line so it can feed the carrier and the H2 ports. Is there no make-up gas for the detector?

[Kashew]

Nice. Alright. I can do that.

I have a few more questions on this, though. What do I need to buy to do 20:1 split sampling? I'm assuming its just one of the glass inserts?

Also, can I just get any oil-less compressor from the Home Depot to feed the zero air generator(as long as it's between the min 40PSI and max 150PSI)?

[Johnny Rod]

You sound like you don't know a great deal about this, so I'd recommend getting hold of the manuals. If you can't download them from Agilent (also searhc on here as well) then get the ones for the 6890, it's a later model of the same thing.

I don't know about the zero air generator, it should have some specs on the feed, but I would guess so.

What sort of injectors and detectors have you got in the GC? If it's an older one then they could well be packed column type in which case they're not made for split injection (as packed columns have a high sample capacity so no need to split) and no facility for make-up gas (as the packed flow is high enough - capillary would be low so make-up is needed). The inlet/injector inserts should be the ringht ones for sure but they don't tell it how to work.

Also what size and type of column are you using? Does the GC have electronic pressure control (EPC) or a load of gauges and knobs on the left hand side of the fascia?

[larkl]

You should have four gas inlets.
Carrier (hydrogen)

FID Air
FID Fuel (hydrogen)
FID Makeup (helium or nitrogen)

You can't run split mode, unless you have a split inlet. If it's a pneumatic instrument, then the split is set by balancing the column and split vent flows. If its's EPC, then you can control this electronically.

[Kashew]

Alright, to clear up things, I've taken some neat-o pictures of everything so you guys can see what I'm working with. As for the capillary column, I was looking to order this:

https://www.sigmaaldrich.com/catalog/Pr ... KEY&F=SPEC

to fullfill this:

Column: 15 m x 0.25 mm, 0.25 μm;
Phase: 5% Diphenyl – 95% Dimethylpolysiloxane
Carrier: Hydrogen, 1.1 ml/min, constant flow
Injector: Split/splitless, 280°C
Split ratio: 20:1
Oven: 2 min at 200°C, 10°C/min 200-240°C, 2 min at 240°C
Detector: FID 300°C, H2 35 ml/min, Air 350 ml/min
Internal standard: Tribenzylamine (TBA) in ethanol (0.5mg/ml)
Injection: 1.5 μl, Split


Here are the pictures(bottom air valve is labelled "carrier", fyi):

http://i.imgur.com/Lm45s.jpg
http://i.imgur.com/KT2qM.jpg
http://i.imgur.com/0UF97.jpg
http://i.imgur.com/Kqdzy.jpg
http://i.imgur.com/HEGiJ.jpg

Also, can anyone tell me if I'll need connecting ferrules or anything for the column?

[Consumer Products Guy]

I'd get column nuts (Agilent) and graphite ferrules to connect the column to the inlet and FID. The column "may" arrive with 2 ferrules, but if that is all you have, and one fals on the floor and gets lost....good luck. And make sure you have the correct type of inlet liners (e.g. FocusLiners) and inlet septa. And the correct type of syringe, and several back-up syringes. Also a column cutter, like a scoring wafer or tiny file, to break off 1/2 inch of column after you insert through a ferrule.

[Don_Hilton]

Also,

When putting things together, check for leaks, both on connections outside the GC and on the inside. There are electronic leak detectors that work well. These are great for gasses such as helium. Avoid snoop, as residues can make it into the plumbing.

It would be a really good idea to find someone locally who can mentor you on the use of a GC. There are all kinds of things that can happen which will not be thougth of in a conversation, but an esperienced user just walking past the instrument will notice.

[Kashew]

I'd get column nuts (Agilent) and graphite ferrules to connect the column to the inlet and FID. The column "may" arrive with 2 ferrules, but if that is all you have, and one fals on the floor and gets lost....good luck. And make sure you have the correct type of inlet liners (e.g. FocusLiners) and inlet septa. And the correct type of syringe, and several back-up syringes. Also a column cutter, like a scoring wafer or tiny file, to break off 1/2 inch of column after you insert through a ferrule.

I am getting an autosampler. It hasn't arrived yet though.

Is this ok for a liner?

http://www.sigmaaldrich.com/catalog/Pro ... KEY&F=SPEC

Do you have any idea what ferrules I will need? Also, do you have any suggestions for inlet septa?



Don_Hilton: Do you have a suggestion for a lower cost leak detector or a brand/retailer I should start with?


Thanks for the advice so far, everyone.

[Don_Hilton]

The leak detector in my lab is made by Restek. A check with other vendors of chromatography supplies will show some other detectors.

[Consumer Products Guy]

I'd get column nuts (Agilent) and graphite ferrules to connect the column to the inlet and FID. The column "may" arrive with 2 ferrules, but if that is all you have, and one fals on the floor and gets lost....good luck. And make sure you have the correct type of inlet liners (e.g. FocusLiners) and inlet septa. And the correct type of syringe, and several back-up syringes. Also a column cutter, like a scoring wafer or tiny file, to break off 1/2 inch of column after you insert through a ferrule.

Is this ok for a liner?

http://www.sigmaaldrich.com/catalog/Pro ... KEY&F=SPEC

Do you have any idea what ferrules I will need? Also, do you have any suggestions for inlet septa?

That liner will physically fit, and do the job, more expensive than what we typically use, due to glass funnel-cup inside. You can purchase septa from Sigma-Aldrich Supelco as well, I'd start with all-purpose low bleed type. Graphite ferrules i.d. should match that of the o.d. of the column. Typical sizes are 0.53mm, 0.32mm, 0.25mm, 0.20mm.

[Kashew]

That liner will physically fit, and do the job, more expensive than what we typically use, due to glass funnel-cup inside. You can purchase septa from Sigma-Aldrich Supelco as well, I'd start with all-purpose low bleed type. Graphite ferrules i.d. should match that of the o.d. of the column. Typical sizes are 0.53mm, 0.32mm, 0.25mm, 0.20mm.

What size septa should I be looking for? I have no clue which size to get from this list:

http://www.sigmaaldrich.com/analytical- ... =104061276

Also, are these ferrules acceptable? The column's ID is 0.25mm.

http://www.sigmaaldrich.com/catalog/Pro ... KEY&F=SPEC


Also, is this what I'm looking for to score the column so I can take off the last half inch?

http://www.sigmaaldrich.com/catalog/Pro ... KEY&F=SPEC


Finally, for the splitting of the Hydrogen gas, I know I need these:

https://www.sigmaaldrich.com/catalog/Pr ... |BRAND_KEY
http://www.sigmaaldrich.com/catalog/Pro ... KEY&F=SPEC

But what do I need in the way of ferrules(1/8 in OD)?

[Chenosuke]

Hi Kashew,

So far it sounds as if you are going to be running a similar setup to my 6890. Based on your liner and column specs, you may require the 11mm low bleed septa in the list you posted. Also remember to buy O-rings to seal the liner as well.

As Johnny Rod said earlier, it would be advisable for you to get a hold of the instrument manuals as they provide most (if not all) of the information you require to get started as well as instructions for general maintenance and troubleshooting.

Edit: The 0.4mm ferrules will fit your column.

Hope this helps!

[Kashew]

Hi Kashew,

So far it sounds as if you are going to be running a similar setup to my 6890. Based on your liner and column specs, you may require the 11mm low bleed septa in the list you posted. Also remember to buy O-rings to seal the liner as well.

As Johnny Rod said earlier, it would be advisable for you to get a hold of the instrument manuals as they provide most (if not all) of the information you require to get started as well as instructions for general maintenance and troubleshooting.

Edit: The 0.4mm ferrules will fit your column.

Hope this helps!

Chenosuke, thank you.

I will be getting these septa and these o-rings:

https://www.sigmaaldrich.com/catalog/Pr ... |BRAND_KEY
http://www.sigmaaldrich.com/catalog/Pro ... KEY&F=SPEC

As for the manual, I do have the manual, but it is terribly unspecific. I will actually upload it later just in case anyone wants it for reference in helping me(again, thank you all so much).

As for the ferrules on the gas plumbing from the generators to the GC, I'm not really sure how it works assembling it. Do I just twist the back and front ferrules together on the tubing? I've been trying to find a video so I can figure out whether I just need to get some front and back ferrules to use my Swagelok tee or whether I need a tool for it too.

[Chenosuke]

Looking at the ferrules and tee you ordered, basically what you have there is a compression-sealed fitting.
What you would do is to unscrew the nut from the tee and push the copper tubing through it.
Then you put the tubing through the back ferrule then the front ferrule with the tapered end facing forward.

It should look like this

http://i39.tinypic.com/2ngr9tz.jpg

Push the tubing into the tee inlet and slide the nut up and screw it on (you may use a small adjustable wrench to tighten). Take care not to overtighten though. You can finger-tighten and then when it stops, go maybe a quarter to half turn with the adjustable. That should do it.