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Obelisc HPLC Column

Obelisc HPLC Column a new technology to separate small molecules.

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Two complimentary columns, Obelisc R and Obelisc N, based on Liquid Separation Cell ( LiSC ™) technology, offer a new approach to separate a variety of small molecules. Buffer concentration, buffer pH, and organic modifier concentration are three orthogonal parameters of the mobile phase that allow adjustment of column properties to separate complex mixtures.

Obelisc™ HPLC columns are the latest, innovative columns from SIELC Technologies, the inventors of Primesep. With multiple patents pending, Obelisc columns are the first commercially available columns with Liquid Separation Cell technology ( LiSC ™). Obelisc R, with reversed-phase characteristics, and Obelisc N, with normal-phase characteristics, separate polar and non-polar compounds using multiple separation mechanisms.

Why shoud I buy Obelisc Column

This cost effective duo replaces multiple HPLC columns such as reversed-phase (RP), AQ-type reversed-phase, polar-embedded group RP columns, normal-phase, cation-exchange, anion- exchange, ion-exclusion, and HILIC (Hydrophilic Interaction LIquid Chromatography) columns.
Method development is simplified by using only two Obelisc columns and a few simple mass spec or low UV (<220 nm) compatible mobile phases. Obelisc R and Obelisc N differ in the type and proximity of their charged groups and the hydrophobicity of their long chains. Obelisc R has cationic groups close to the silica surface separated from anionic groups by a hydrophobic chain. Obelisc N has anions close to the surface separated from cationic groups by a hydrophilic chain.


Obelisc R interactions Obelisc N interactions


Obelisc R and Obelisc N Columns – A Powerful Duo for HPLC

  • Two columns able to retain and separate all types of small molecules and their mixtures
  • Fast method development with only two columns
  • Simple mobile phase selection
  • Multiple separation modes (RP, NP, HILIC, IE)
  • Mass spec, ELSD, preparative and low UV (<220 nm) compatible, low concentration buffers.
    Adjustable selectivity in all modes based on organic content, pH, and buffer strength

Applying Obelisc liquid separation cells to chromatographic separations provides very different results from all other chromatographic columns. Charge and chain conformation are tunable properties that allow dramatic changes in separation selectivity. Method development now returns to an experimental science rather than trial-and-error screening of columns.
Figure 1 shows the separation of a mixture with similar mobile phases on Obelisc R and N. Peak order is reversed just by changing acetonitrile content in the mobile phase. The hydrophobic propyl paraben retains much longer on Obelisc R due to the column’s reversed-phase characteristics. The polar compounds, dopamine and DOPA, retain much longer in normal-phase mode on Obelisc N.

Obelisc R and Obelisc N – Propyl paraben, Dopamine, DOPA – chromatograms

Loading capacity of Obelisc R column

Obelisc columns have high density of positive and negative ions on a stationary-phase surface. This property is favorable for using Obelisc column for preparative chromatography. The Obelisc columns offer significantly higher loading capacity (more than 10 times) with charged compounds compared to traditional RP columns. Neutral molecule can be preparatively separated on Obelisc similar to other RP columns.

Having two opposite charges allows to retain polar compounds on Obelsc columns without using ion-pairing reagents.
Obelisc technology allows to use much higher organic concentration than traditional RP columns while separating polar compounds.

Obelisc N is a column which has very polar characteristics and works well for polar and charged analytes.
Obelisc N offers both positively and negatively charged groups to interact with positively or negatively charged analytes.
Multiple separation modes (NP, HILIC, IE).
In HILIC mode, Obelisc N offers different selectivity form other HILIC or bare silica columns.
Mass spec, ELSD, preparative and low UV (<220 nm) compatible, low concentration buffers.
Obelisc N columns are available in all standard dimensions
Column IDs: 22 mm, 10 mm, 4.6 mm, 3.2 mm, 2.1 mm, 1 mm, 0.5 mm, 0.25 mm
Column Lengths: 250 mm, 150 mm, 100 mm, 50 mm, 25 mm, 10 mm
Particles: 10 um, 5 um
Pores: 100 A

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