How did we get 0.53mm i.d. columns

Discussions about GC and other "gas phase" separation techniques.

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Hi All

How did we end up with 0.53mm columns rather than just 0.5mm columns in GC? It does not appear to be an obvious imperial conversion either.

Thanks!
Interesting question. I wonder if it has to do with the outside diameter or something like that.
The past is there to guide us into the future, not to dwell in.
I remember reading - several decades ago - the story of Hewlett-Packard developing the fused silica capillary columns about 1979. That was before the science part of HP became Agilent.

Glass capillaries broke readily, and the ends needed to be straightened. So the story went something like this, according to the article. A scientist figured that fused silica would be inherently straight, so he looked for manufacturers of fused silica. He was told, sorry, our fused silica has a hole/channel running through it, and the guy put 2 and 2 together. A polyimide coating protected the column from breakage, and non-polar phases could be deposited on the inside channel. Eventually bonded phases were developed. Hewlett-Packard decided to allow other companies to use the invention too.

https://www.agilent.com/about/features/ ... tical.html

https://patents.google.com/patent/US4293415A/en
When I first started work in 1991, I remember that Restek always put on their columns something like "manufactured using Hewlett Packard patent" or something like that. They were the only third party I knew of that actually gave credit to HP for the design.
The past is there to guide us into the future, not to dwell in.
I asked Paul Silvis and Jaap de Zeeuw for their thoughts on the matter...

Paul said that he wasn't sure what exactly set 0.53 or 0.32 as the standard. One thing he did say is that the OD of the 0.32 fits pretty much perfectly in the 0.53. But again, no explanation as to why those values were chosen.

Jaap similarly has no suggestion for the 0.53 vs 0.50. He suggested though that the 0.32 comes from an era of glass columns where they were doing on-column injections and the standard sized needle at the time fit the 0.32 mm size.

I say all this to answer with: Not sure.... :lol:
I suspect that Prof. Walter Goodrich Jennings (God rest his soul) was probably involved in some part of the decision.
https://www.agilent.com/en-us/products/ ... t-jennings

I had the pleasure and honor of meeting Prof. Jennings and visiting his facility in Folsom California in the early '80's. Got to witness firsthand the J&W Elves hard at work spinning the magic glass into miles and miles of capillary tubing.

Crabs
TCCrab wrote:
I suspect that Prof. Walter Goodrich Jennings (God rest his soul) was probably involved in some part of the decision.
https://www.agilent.com/en-us/products/ ... t-jennings

I had the pleasure and honor of meeting Prof. Jennings and visiting his facility in Folsom California in the early '80's. Got to witness firsthand the J&W Elves hard at work spinning the magic glass into miles and miles of capillary tubing.

Crabs


I remember meeting the W of J&W though I can not recall his name. I met him at Pittcon where he was displaying the first Spinbar extraction which his company was making. He also was talking about using a cap liner coated with adsorbent similar to how SPME works, you would put the cap on a bottle, rotate the bottle for a time and it would extract the analytes.

I swear I have been searching for an hour online for his name but I can find no reference to the other half of J&W, it is like he was erased from existence after breaking off and forming his own company.
The past is there to guide us into the future, not to dwell in.
I also met the "W" of J&W some years back. He actually visited my lab on some errand, don't remember exactly what it was. We chatted for a long time and remember being awestruck that he was a founding father of J&W along with Prof. Jennings, whom I had met much earlier.
Had to dig deep to find his card, but I find it I did.
The elusive "W" is Dr. Robert Wohleb.
http://www.speciation.net/Database/Comp ... -;i1465a-1

'Crabs
TCCrab wrote:
I also met the "W" of J&W some years back. He actually visited my lab on some errand, don't remember exactly what it was. We chatted for a long time and remember being awestruck that he was a founding father of J&W along with Prof. Jennings, whom I had met much earlier.
Had to dig deep to find his card, but I find it I did.
The elusive "W" is Dr. Robert Wohleb.
http://www.speciation.net/Database/Comp ... -;i1465a-1

'Crabs


Ah yes, that was definitely him :) I remember he was a very nice fellow and very eager to share his work when we spoke.
The past is there to guide us into the future, not to dwell in.
As to the 0.53, I suspect more an issue of the ability to make the raw fused silica tubing than anything but I do not know.

As to the larger bore, J&W rolled out 0.53's as the plug and play replacement to packed columns. Flow rates on the order of 8 - 25 mL/minute which is in the range of standard packed columns so you would use a fancy insert and just use the packed injector and flow controller but stand to benefit from the superior performance of a capillary column. Man - that's reaching way back into my early days.....

Best regards,

AICMM
James_Ball wrote:
When I first started work in 1991, I remember that Restek always put on their columns something like "manufactured using Hewlett Packard patent" or something like that déménageur Le Havre. They were the only third party I knew of that actually gave credit to HP for the design.

This is very important information for us. This will serve as a basis for us to begin our research.
This was a very informative thread!
Many labs were drawing their own columns long before fused silica became available commercially. IIRC, spending all night in the lab, borosilicate maybe, the resulting dimensions were dependent on the roller size, draw rate and temperature of the furnace. Size of the original plug may have been important as well. That started setting the standard for sizes since draw rate, et al knowledge was passed between those of us stupid enough to get roped into making columns. You could spend days drawing, stabilizing, coating and usually breaking the dam thing. A number of manufacturers had glass drawing systems available.
Fused silica columns were produced using the same hot drawing machines as were used for optical fibres - that may be why HP had a lead on the other chromatography companies. The fibres started off as tubes that were doped on their inside surfaces so that they acted as waveguides when the tubes were drawn out into very fine fibres. The folklore on the column sizes is that there were only a few feedstock tube sizes available, and there was such a race to get silica columns to market (people would leave in the middle of conferences to rush home and apply what someone had let slip) that nobody wasted any time optimising feed stock sizes to get sensible column diameters, they just went with what they had. Apparently 0.53 is as big as they could make the tubes and still wrap them onto column cages. Optical fibres have a coating to stop moisture corroding the outside, but that coating does not stand GC temperatures, and although making a silica tube was pretty straightforward, stopping it from breaking into small pieces was the real challenge, solved by polyimide baked onto the capillary as it was drawn. Early versions of polyimide would gradually darken as they oxidised, and then corrosion would make a stress riser on the column and it would break. The very early silica columns had such strongly acidic surfaces that the amines in the usual test mixtures would dissapear completely, and so there was a lot of work on deactivating the inner surface before silica was anything like as inert as borosilicate glass.

HP were very shrewd - although they held the patent on the column drawing process they did not restrict its use while the other companies were solving the high temperature external coating and deactivation problems, and convincing everyone to switch to silica. Once the silca market was irrevocably established they started to enforce the patent.

I spent many happy hours tending a machine that drew coiled glass columns, and with a few adaptations it could also produce the straight lengths of various sized capillaries that were the feedstock for the first press-fit connectors and T-pieces. The coiled columns had to have the ends straightened to go into the inlet and detector. The standard method used a flame, but I was hopeless at it so I made an electrical one; https://www.researchgate.net/publicatio ... ry_columns

Happy days !
Peter Apps
And HP was the leader in GC systems, and this didn't hurt their instrument sales.

In those days, HP/Agilent was just getting into the HPLC business; we had a 1084B which used the mainframe from the HP 5840 GC.
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