Separation Service Berlin
Helmholtzstr. 2 - 9, Aufg. L, D-10587 Berlin

Tel.:  (030) 393 09 91    Fax: (030) 393 49 25  oder  391 01 000

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Selectivity Pack RP

With every selectivity pack you get for the ordered column dimension two columns filled with RP packings of the same particle diameter, but with guaranteed different separation selectivities (2 x C18, 2 x C8 or C18/C8).

One of the combined packings was produced with a threefunctional silane, the other one carries alkylmethyl groups. The residual silanols, which contribute decisively to the separation selectivity, are in both cases reproducibly determined by the synthesis. On request both columns or one column can be delivered endcapped. For all combinations of columns we give a discount of 10 % according to the price list.

What is the advantage?

For instance you develop a method and optimize a separation problem, but somewhere in the chromatogram you cannot achieve the necessary solution. Up to now you had to buy a second separation column, the properties of which were in most cases not fully known to you. Now this is past. With our selectivity pack you can test your separations without loss of time immediately with two phases, which possess different selectivities on principle. You save time and money !


The chromatograms demonstrate the different selectivities of two RP columns for the example of organic nitrogen compounds. Eluent: water /acetonitrile (6/4).

Column A:

Column B:


modified trifunctional

modified bifunctional

Column A separates compound 1 and 2 nearly totally, 3 and 4 are separated only to 50%


Column B does not separate 1 and 2 (compound 1 migrates with peak reversion to the back),
but 3 and 4 are separated very well










HPLC Columns

Special Columns


Food Stuffs


Clinical Chemistry


Chiralic Analysis

Ion Exchangers