U-VDSpher® PUR Phases

More and more users are using UHPLC (Ultra High Performance Liquid Chromatography) for their analysis, due to short analysis times, high efficiency and accordingly, a high economy of the analysis together with the high commercial availability of UHPLC systems and columns.

 For UHPLC, suitable packaging materials and columns must satisfy certain claims. Short analysis times are achieved with small column dimensions, the desired high chromatographic resolution however, cannot be achieved with the particle sizes used normally in HPLC. For the UHPLC therefore, silica gel with particle diameters less than 2 µm have come up (“sub-2-µm particles”). Very high plate numbers are achieved with these bulk materials, leading to a very high resolution.

Due to the small particle size, pressures of up to 1200 bar may be expected in UHPLC applications. To guarantee stability of the column packing at high pressures, special processes of column production are required. VDS optilab works continuously on the further development and optimization of production plants and product processes for the manufacture of UHPLC columns. Nevertheless, it must be mentioned that at pressures of over 800 bar, one should expect a shortening of the life of a column over a period of time.

With U-VDSpher columns, VDS optilab offers the ideal solution for UHPLC applications. The different U-VDSpher separation phases have the required small particle size of 1.8 µm and the columns are packed in a special production process. These are therefore, ideal for the requirements of UHPLC.

The available U-VDSpher PUR 100 normal and reversed phase modifications are shown in the Table.

Normal and Reversed Phase Modifications: U-VDSpher® PUR 100

Phase cModifikation Endcapping Carbon content
Nitrogen content
SIL None no 0 0 L3
CN Alkylnitril yes 6.5 1.3 L10
CN-RP Alkylnitril yes 6.5 1.3 L10


Alkylamin no 4.0 1.5 L8
C18-E C18 yes 16.8 0 L1
C18-M-SE C18 yes (special)


0 L1
C18-H C18 yes (polar) 11.5 0 L1
C8-E C8 yes 10.0 0 L7
Phenyl-E Alkylphenyl yes 10.0 0 L11
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