Chromatography Forum

Hi folks,

Wonder if someone could help here. I'm coupling 2 Jordi PS-DVB (100 A) columns together for separating glycerol monostearate. The mobile phase is THF. Detection is via RI.

The setup work for us before. However, one of the columns recently died and was replaced by another one. We were assured its the same type; indeed it was. However, I noticed the new column has a different catalog number. So effectively, I'm coupling 2 similar columns with different catalog numbers.

Is this really a cause for concern? The analysis doesn't work now - we keep getting a negative peak where the free glycerol should elute. This is happening even hours of equilibration and balancing. Mobile phase the culprit?

Thanks in advance.

normally companies issue a new part number because something has been changed and it is a new product.

on rare occasion they will change the part number and the product will be the same but then they should have some sort of manufacter's information bulletin declaring that the change in the part number is purely clerical and that no changes were done to the product.

request such a form, signed and approved by the manufacter's himself on paper or e-paper with the manufacterer's logo and some sort of tracking number.
look at data sheets of the two columns provided by the manufacter. see if the product description is the same

Contact Jordi Associates directly and ask them. They should be at
www.jordiflp.com
You can also check the catalogue numbers of your columns at that site.
I suspect you may now have a mix of their new Fl.A.S.H column technology with their old. May work, depending on which order the columns are run. I found the Jordi technical support to be excellent when I last used it in 1998.

Bruce Hamilton

Thanks unmgvar and Bruce....appreciate your prompt response. I'll follow up on your suggestions.

Thanks so much for all the help folks....it's okay now. We injected the sample onto each of the column separately and found our older column had also died in the meantime. Once again, many thanks all.