Comparison of diff. C18 column

[Crystal]

I am a junior using HPLC. I know there is a difference of result such as Retention Time in chromatogram using c18 column come from different bands in spite of the same condition.

Would anyone give me some websites or journals for learning the factors of column that affect the result of HPLC when the same type(c18) of different bands column is used?. Thank you!

[zompa]

have a look at this book: " Practical HPLC method development" written by Snyder, Kirkland.
Also have a look at the Phenomenex Website.
I found it very interesting.

Zompa.

[josebenjamin]

Dear Crystal,

Many factors affect the retention a given C18 column gives you. Assuming particle size, lenght and diameter are the same, the main factors left are surface area and %C.

The larger the surface area of the adsorbent the more sites of interaction you will have between sample and C18 groups and therefore more retention. In the same fashion, as the %C increases the density of C18 groups over the surface also increases with the same effect.

Take a look at the Phenomenex catalog, there you will find a table listing the basic characteristics of many columns including Surface area, and %C.

Good Luck,

josebenjamin

[Bryan Evans]

In addition to surface area and % C, there are:

1. C18 columns that can retain polar analytes. These columns
offer a different selectivity from conventional C18 columns.

http://www.silvertonesciences.com/modul ... TI117E.pdf

2. Monomeric vs. Polymeric bonded phases. The polymeric
bonded phases have the advantage of being more stable
at lower pH. In the past, it was believed that these columns were not
as reproducible as monomeric columns. However, this is no longer the
case. Our columns are manufactured using a proprietary
packing/endcapping technology. The result is excellent batch to batch
reproducibility.

http://www.silvertonesciences.com/modul ... TI008E.pdf