External Column heater

[jadiyaa]

Can someone please suggest a manufacturer who still makes external column heaters for HPLC. I am stuck with running Mannitol Assay according to EP monograph which suggest the run should be done with column temp @ 85 C. Furthermore EP suggests that Assay and Related substances should both be done at 85 C.
USP has given flexibility to run between 30-85.

We have agilent 1100's and none of the attached column heaters can go up that high. I searched around and couldn't find one which can go upto that high temp.

If someone has ran into this problem before, please guide me what's the outcome.

[juddc]

Eppendorf makes units that will reach 150 deg C, I believe. I have two CH-430's with controllers and they're quite robust. Google Eppendorf CH-430 and you'll find them. I think Supelco sells them.

[Jumpshooter]

Is it possible to go into your method settings and adjust the max column temp?

[Bruce Hamilton]

Doesn't the 1100 column heater go to 80C?. Why woory about the extra 5C?.

I'd suggest a water bath with circulator if you really have to be at 85C.

Please keep having fun,

Bruce Hamilton

[zokitano]

Also consider about using a column with extended temperature range (up to 80C)

Regards

[danko]

Hi jadiyaa,

I know Waters make an external column heater with a belonging controller (i.e. Column compartment and TCM). The good thing is, they do not necessary need to be controlled by software, so that you’ll need to think about compatibility.
I’m not 100 % sure, but I think they can be utilized at up to 90 degrees Celsius. Try to ask your local Waters representative.

Good luck

[DR]

Metatherm is an alternative to Eppendorf, but I'm not sure they go to 85°C.

[Jim Shen]

Can someone please suggest a manufacturer who still makes external column heaters for HPLC. I am stuck with running Mannitol Assay according to EP monograph which suggest the run should be done with column temp @ 85 C. Furthermore EP suggests that Assay and Related substances should both be done at 85 C.
USP has given flexibility to run between 30-85.

We have agilent 1100's and none of the attached column heaters can go up that high. I searched around and couldn't find one which can go upto that high temp.

If someone has ran into this problem before, please guide me what's the outcome.

A couple of suggestions:

Agilent 1100 Column Oven goes up to 80 degrees
Agilent 1200 Column Oven goes up to 100 degrees
Shimadzu 10AD series Column Oven goes up to 80 degrees

We also have a column oven made by Selerity called Polaratherm which goes up to 200 degrees.

Also Analytical Sales and Services has a line of simple external column oven that can go as high as 80 degrees.

[ivanvins]

Just one option from a many (in german)

http://www.techlab.de/produkte/geraete-ofen-t1.php

the eppendorf ones are sold by Alltech (Grace)

http://www.discoverysciences.com/product.aspx?id=3096

for your type of analysis (i suppose you are using the ion exclusion chromatography on sulfonated polysterene) the high temperature is rather esential and in fact the only parameter influencing the selectivity on a given column.

Look for column thermostat with a capability at least up to 100 C, as there may be a remarkable difference between 85 and 90 C. Preferably the immersion type - it is not much convenient for column exchange, but the heat transfer is a critical here as a temperature gradient in the column may spoil the separation. Forced air convention types may require some eluent preheating and usually do no go over 85 C. The Agilent 1100 column compartment can be set up to 80 C, but you will never reach this temperature in the column.

[Jim Shen]

Just one option from a many (in german)

http://www.techlab.de/produkte/geraete-ofen-t1.php

the eppendorf ones are sold by Alltech (Grace)

http://www.discoverysciences.com/product.aspx?id=3096

for your type of analysis (i suppose you are using the ion exclusion chromatography on sulfonated polysterene) the high temperature is rather esential and in fact the only parameter influencing the selectivity on a given column.

Look for column thermostat with a capability at least up to 100 C, as there may be a remarkable difference between 85 and 90 C. Preferably the immersion type - it is not much convenient for column exchange, but the heat transfer is a critical here as a temperature gradient in the column may spoil the separation. Forced air convention types may require some eluent preheating and usually do no go over 85 C. The Agilent 1100 column compartment can be set up to 80 C, but you will never reach this temperature in the column.

When the engineers installed my Agilent 1200 column oven they used some kind of flow through tester (essentially a dummy column with a thermocouple inside) to do the IQ/OQ. He showed me that the thermocouple's temperature indeed reached 100 degrees when the column oven was set to the same. Maybe their method is flawed? Please expand on your statement..

Thanks

[ivanvins]

It was my experience with 1100, using ion exclusion columns. There was a remarkable difference in efficiency and resolution when the same column was used at 80C in the 1100 column compartment and in a water bath thermostat. The 80C in 1100 was corresponding to a cca 70C in reality. I do not have experience with 1200, nor the 1100 was validated though.

[ivanvins]

Re Agilent column compartment: A possible reason (and a flaw in the testing method) - the Agilent column compartment heats the column primarily by preheating the mobile mobile phase, the compartment itself is a rather badly insulated and the contact of the column with the heaters is not ideal. This will work well for small columns with high flow rates, but you are using 8x300 mm columns with 0,3 - 0,5 ml/min typically for IEX.

[Mark Tracy]

When operating at elevated temperatures, preheating of the mobile phase is essential to good results. Even water-bath designs benefit from a preheater. The protocol for the 1200 was not flawed-- it demonstrated that when used as directed by the manufacturer (that is with the preheater) it worked correctly.

For what it is worth, the Dionex TCC-3000 column ovens go up to 85° and have a variety of optional preheaters to match the flow rate and column size. Also Pickering Laboratories has an external heater that goes to 100°, and includes a preheater.

[Uwe Neue]

I second Mark. Heat transfer through the column wall into the bed does not work. It is essential to preheat the mobile phase to the desired temperature before it reaches the column inlet.

[Bruce Hamilton]

The USP method uses the same sort of column ( strong cation resin, calcium form, similar particle size ), but smaller column diameter 4 v 7.8 mm, and slightly shorter length 25 v 30 cm.

If the USP allows 30 - 85C +-2C, I can't see why the EP is so fussy about 85C +-1C, especially as both are about 0.5 ml/min, which means the mobile phase ( water ) doesn't transfer lots of heat. For the columns I've used, the HETP improvement with temeprature drops off after about 65C.

I've found a water bath works well for a similar column ( Aminex HPX-87H ), even with just 1 m of 10 thou PEEK tubing as the preheater in the same water bath. That's around 6 seconds tubing contact time before the column. The biggest problem was thermal stability of the RI detector - the lines had to be insulated.

Bruce Hamilton