Packing a Packed Column

[pochengjean]

Does anyone know how to pack a packed column? What are the equipments required for packing?

Thanks and best wishes.

[tom jupille]

Wow, does that bring back memories!

What you need:

• 1. the column
  2. glass wool to plug the ends
  3. the packing material
  4. a clip-on funnel to put on one end of the column
  5. a low vacuum source (e.g., water aspirator)
  6. flexible tubing to connect column to vacuum source
  6. a vibrator
  7. lots and lots of patience.

What to do:

• 1. Stuff a piece of glass wool in the outlet end of the column, then slip on the flexible tube and connect to the vacuum source.
  2. Clip the funnel on the inlet end of the column.
  3. Gently pour some packing into the funnel.
  4. Turn on vibrator and press against column.
  5. Repeat steps 3-4 as necessary to fill the column.
  6. Stuff some glass wool in the inlet end of the column.

This is a lot easier to do with glass columns than with metal (you can see what's happening). It takes some practice to get it right.

[pochengjean]

i am relatively new to this. I have worked with GC for sometime but have never packed a packed GC column in my life, considering that i just graduated from school and packed column was pretty much abandoned back in 80's.

Thank you for your reply, and I will try that tomorrow. That is helpful.

[Consumer Products Guy]

We only use packed-column for one assay these days, but we buy it pre-made from Supelco. Tom has listed a good procedure. Maybe he remembers the early days when people would stand on a crooked stairway to pack the long columns used then due to column efficiencies, or break bricks into powder for packing (both those were before my work time, however, but one in the department did those). Sometimes we use a glass wool inserter tool, sometimes just stuffed it in using paper clips. I believe Tom also means for you to use SILANIZED glass wool, not plain old glass wool, and stainless stell 1/8 inch tubing would be better than copper. I think nickel tubing was "hot" for a while, but we never used it here.

[tom jupille]

Maybe he remembers the early days when people would stand on a crooked stairway to pack the long columns used then due to column efficiencies, or break bricks into powder for packing (both those were before my work time, however, but one in the department did those). Sometimes we use a glass wool inserter tool, sometimes just stuffed it in using paper clips. I believe Tom also means for you to use SILANIZED glass wool, not plain old glass wool, and stainless stell 1/8 inch tubing would be better than copper.

I'm not that old (only as a far back as the early seventies)! And, good point about silanized glass wool instead of regular. The Alltech, Supelco, et al catalogs still list things like funnels, vibrators, etc. for packing columns.

[pochengjean]

sigh....another problem popped.

To make a long story short, we decided decided to pack the packed column ourselves just to save couple hundred bucks. So, we ordered an already packed glass column(Poropak Q as the packing material) , and an empty packed glass column.

Now, I packed the packed column and I will need to qualify the column I packed so that it has the same performance as the one we ordered.

In order to qualify a column, what are the criteria I will be looking at?Theoretical plates, peak width, peak hight? Also, what is the "reference" chemical compound I have to use to qualify this column?

[tom jupille]

Ideally, run standards of whatever it is you will be analyzing.

As a minimum, check theoretical plates (that will tell you how good a job you have done packing the column). While you're at it, you may as well check retention time (you have the data anyway), and it wouldn't be a bad idea to measure flow rate and/or back pressure as a "baseline" for the future.

PorapakQ is polymeric (as opposed to a greasy liquid phase coated on a support) and so is less prone to selectivity problems. If you don't have a particular sample in mind, you can get standard check samples from most of the "usual" suppliers.

[dpr]

http://www.chromatography.co.uk/techniq ... ations.htm

Theoretical plate calculation here.

Regards

Dave

[Mark]

Another consideration when packing your own columns especially with the polymeric packings is that after packing initially you want to run the column through a few temp programs up to its max or vary near and then remove the column, reselltle the bed, and most likely will have to top the column off with a little more packing (I have packed these before). The packing tends to shrink and settle after the first attempt no matter how well you pack it initially. Good luck with this effort.

Regards,
Mark

[pochengjean]

Great, so this is what i will do for the packing.

1. Stuff a piece of SILANIZED glass wool in the outlet end of the column, then slip on the flexible tube and connect to the vacuum source.
2. Clip the funnel on the inlet end of the column.
3. Gently pour some packing into the funnel.
4. Turn on vibrator and press against column.
5. Repeat steps 3-4 as necessary to fill the column.
6. Stuff some SILANIZED glass wool in the inlet end of the column.
7. Heat the column to its maximun temperature, refill the column if necessary.

After the packing, this is what i will do for the PQ.

1. Calculate the theoretical plates using the reference chemicals. Record the retention time (you have the data anyway), flow rate and/or back pressure as a "baseline" for the future.

I think this will do, but anymore steps needed??

[HW Mueller]

...feel like a Dynosaur. The worst part was that we still put our own liquid phase on the support, Carbowax, etc. etc. A slurry with the liquid stationary phase, a solvent, and the support was made, dried artistically with a rotary evaporatior and then filled (aluminium tubes). Most the times it had to be reslurried or dumped because of lumbs.... Good riddance of the good old days!

[chromatographer1]

The packing process is not as easy as you may think, but I wish you success.

To test your Porapak Q column for voids, shrinkage problems, etc. you might use methanol ethanol isopropanol in water balance as a test sample at 150-180°C isothermally, or natural gas at a lower temperature (50°C) (nat gas contains air, methane (90% balance), 3-5% ethane, 1% propane)

Supelco packs Q columns with a minimum of shrinkage. Voids from shrinkage will cause tailing and loss of plates.

If you are disappointed with packing your own columns you may wish to compare our product against any other on the market.

Good luck and best wishes,

Rodney George
Senior Research and Development Scientist
Gas Separations Research
Supelco
595 North Harrison Road
Bellefonte, PA 16823

814-359-5737 voice
814-359-5459 fax
rgeorge@sial.com