Chromatography Forum

Hey everyone,

Let me give a little background. I'm an undergraduate student of physics working in a university chemistry lab. We were given an HP 5890 Series II GC from the Physics department and I was tasked in figuring out how to get it working and to test it. Basically they just handed it to me and said, "Please have it ready by November. Have fun!" So I dug in.
We decided to set it up as a splitless inlet with a silica capillary column (for now just an old one that was lying around) using He as a carrier gas. Detector is FID. I have collected the recommended traps and purification equipment that I'll need and am just waiting for the Helium to show up.
After much googling, and pouring over the manuals, (which lack quality photos of what I need) I think I've made good progress and have a pretty good idea about how this is going to come together; however, I have a few questions about some very basic hardware setup.

First off, the HP 5890 has 2 intake ports. Now from my reading, one is for split/splitless and has a glass liner. Current liner is empty with a glass wool plug so that's good. The other port is, I believe, for packed inlet. However some of my reading led me to believe that packed inlets also use glass liners. Video's I've watch consistently use the front port, but my reading suggests the back port.
So can either port be used interchangeably? What's the benefit of using a capillary column on a packed inlet over the splitless inlet?

Secondly, the previous owner used some fittings and connectors inside the oven that are not shown in manuals or videos and do not allow simple connection of the column. Whatever they were for, I'm of the opinion that I don't need them and have decided to simply use a gold seal, with stainless washer and a reduction nut attached to the base fitting. The column nuts will just attach to the reduction nut. Is this sufficient?
We do have some old model HP 5890s lying around and I tried using those as references, but each one is pieced together slightly different from the other. Since I'm obviously very inexperienced with this equipment, I'm hoping that some one with a little background will alert me to any big mistakes before I do damage.

Hopefully some of that makes sense. I'd be more than happy to clarify anything that is confusing.
Thanks in advance,
Beta

Hey everyone,
First off, the HP 5890 has 2 intake ports. Now from my reading, one is for split/splitless and has a glass liner. Current liner is empty with a glass wool plug so that's good. The other port is, I believe, for packed inlet. However some of my reading led me to believe that packed inlets also use glass liners. Video's I've watch consistently use the front port, but my reading suggests the back port.
So can either port be used interchangeably? What's the benefit of using a capillary column on a packed inlet over the splitless inlet?

Secondly, the previous owner used some fittings and connectors inside the oven that are not shown in manuals or videos and do not allow simple connection of the column. Whatever they were for, I'm of the opinion that I don't need them and have decided to simply use a gold seal, with stainless washer and a reduction nut attached to the base fitting. The column nuts will just attach to the reduction nut. Is this sufficient?

I think you are on the right track. I would not hook a capillary column to a packed-column inlet. I'm not sure if it can be done but I would guess it's set up for higher flow rates than a typical capillary setup (however I'm not sure on this because I've never had or used a packed column inlet). I would scrap all the "extra" parts that are non-HP standard and start from scratch with what you stated; Gold seal and reducing nut. This reducing nut should be the proper HP supplied nut and graphite/vespel ferrule (or you can order replacements from Restek.com). I don't currently have a 5890 that I use but I've used them in the past. Is yours supplied with manual flow control valves or is it the 5890 Series II Plus with the EPC (Electronic Pneumatic Control)? If you are in need of any parts, Restek supplies many quality aftermarket parts for the 5890 and 6890 GCs. There are other vendors as well but they have been my one-stop-shop for Agilent/HP GCs for quite a while now. And they are inexpensive.

Thank you for your reply.
I'm not sure if the flow control is manual or automatic, but I'm assuming manual. I'll look into that. I'll also take a look at what the standard parts are, though this information has been sketchy up to this point. Since I have to order 2 new gold seal kits, I'll go ahead and make sure I have the right reducing nuts as well. Actually, I think I only have one reducing nut. The other side had some weird swagelok deal with an incompatible end.
At any rate, this helps. I feel a little more comfortable ordering parts and moving forward.

Thanks again.

The manual injector contols have pressure guages on the front of the instrument. The EPC does not.

The packed injector does have a liner and it looks very different than the split/splitless liners. If you're using a 0.25 or 0.32 ID cap column, use the split/splitless injetor. If you're using a packed column or a megabore (0.53 ID) column, use the packed injector.

There are two jets for the FID. One is for packed columns and one is for capillary columns. Make sure the one you have installed is for the type of column you're going to use or you will have problems.

You may want to consider using H2 as the carrier (you have to use it as the fuel for the FID) and N2 as the make-up gas. You'll have better sensitivity and it's less expensive than He.

Use vespel/graphite ferrules. If you use straight graphite, use them on the injector only. They tend to flake off and it's much easier to clean the injector. You may need a 1/4" ferrule for the FID. It would be nice to have a few on hand if the one in the instrument is or goes bad.

Make sure you use a good septum. Restek has Premium Non-stick BTO Septa (P/N 27090 - 50/pkg) that are preconditioned and good to 400C.

If your injections are 10ul or less get the Restek (P/N 24894) syringe. This will work for the 5890 compatible autosampler and hand injections.

For the seal, I like the Dual Vespel Cross Inlet Seals (no metal ring and better seal). If you want the gold it's Restek P/N 22083 - 2/pkg. I like the Siltek treated (Restek P/N 22085 - 2/pkg).

Just for the record, I don't work for Restek. Hope this helps and good luck.

BetaGrumm,

Packed column inlets are a little easier to set up and if you use a megabore column (0.53) they will give you pretty good chromatography. Glass liner for a packed column inlet is available from Restek (and others) but is only necessary if you are very concerned about reactivity.

5890 splitless/split is a bit interesting to set up and even more so with EPC so if you have that configuration, you may want to post so you can get some help.

Best regards,

AICMM

Hey everyone,

First off, the HP 5890 has 2 intake ports. Now from my reading, one is for split/splitless and has a glass liner. Current liner is empty with a glass wool plug so that's good. The other port is, I believe, for packed inlet. However some of my reading led me to believe that packed inlets also use glass liners.

So can either port be used interchangeably? What's the benefit of using a capillary column on a packed inlet over the splitless inlet?

Not sure what you have been reading but for those of us who can remember packed columns the top three or four inches of the packed column is the injection liner and can be whatever material the column is made from (glass or metal).

The ports are not interchangeable, a packed column inlet will lack a split vent to divert flow and will need ~30 ml/Min flows for analysis.