Chromatography Forum

Dear members of this forum,

I want to evaluate others suppliers of columns. Actually I work with a Lichrospher RP-18 with length 12.5 cm and 5 um of particle size.
I would like to know what characteristic I have to evaluate in others columns to work in similar conditions as I am working and maintain the robutness of the methods.
I think the porous size, the length of the column and the particle size are very important but I would like your opinions in order to improve the evaluation.
Thanks in advance for your help,

Tequila

Dear Tequila,

Normally when we talk about column evaluation we think of testing different columns in a given set of conditions and with a specific sample. Then we measure some separation characteristics, such as tr, N, TF, k´,R, etc.

You seems to be thinking more in terms of finding a column similar to the one you are using now. On this regard, there some column characteristics that could be important besides the ones you mentioned. These could be, Silica Type (I, or II), Polymeric or Monomeric coating, and endcapping or no encapping and the chemistry of it. Perhaps you should consult the Phenomenex catalog, there you will find an extensive table with information about many columns, you can locate Lichrosphere RP 18, and then select some of similar characteristics in the same table.

Good Luck,

josebenjamin

First of all, there is no guarantee that you can find any column which will match your separation without at least some mobile phase adjustment.

If you want to try, there is a column selectivity database (called Column Match) of something like 300 columns set up to find the most similar (and most different) to any given column. As I recall, it's free to evaluate for 30 days or so: http://www.rheodyne.com/products/chroma ... /index.asp

By way of "truth in advertising": I helped work on this database when I was at Rheodyne (but it's a nice product anyway )