Data Sheet (pdf)

ZIC®-Hilic

for the seperation of polar substances
HILIC is a separation technique suitable for polar and hydrophilic compounds, and is orthogonal to reversed phase liquid chromatography (RPLC). Compounds that have little or no retention and that may be affected by wettability problems on RP-columns generally have strong retention on a ZIC®-HILIC column. The highly polar zwitterionic stationary phase provides a unique environment, particularly capable of solvating polar and charged compounds via weak electrostatic interactions, as apposed to the strong electrostatic interactions obtained with plain silica or amino HILIC phases. In practice, this provides the chromatographer with a larger degree of freedom when choosing among buffer salts and ionic strength in method development.

Separation is carried out using an eluent containing a high content of water miscible organic solvent (e.g., acetonitrile) to promote hydrophilic interactions between the analyte and a water wetted hydrophilic stationary phase, and is thus as technique in principle comparable to traditional normal phase chromatography. However, with respect to analyte solubility in the mobile phase and matrix compatibility, HILIC is superior, as the mobile phase compositions used are comparable to reversed phase separations.

Schematic illustation of the ZIC®-HILIC stationary phase.
An additional advantage is that the more volatile mobile phases increase the sensitivity with LC/MS applications. The latter is in particular true for the ZIC®-HILIC column, as it can provide a selectivity benefiting from both hydrophilic- and weak electrostatic interactions, while maintaining a low eluent ionic strength, thus making the column an ideal choice for LC/MS analysis.

Retention factor (k’) for adenine (squares) and cytosine (triangles) as a function of the concentration of acetonitrile (closed symbols) or methanol (open symbols) as organic modifier in the eluent.

Solvent Strength in Hilic Seperation

HILIC as separation technique is orthogonal to reversed phase liquid chromatography, and thus the solvent strength is likewise the opposite. The figure on the left illustrates the relationship between k’ and the choice of organic modifier for the separation of adenine and cytosine.

The weakest solvent for HILIC chromatography, acetonitrile provides higher increase in retention compared to methanol. The latter solvent is although a viable alternative, and may possibly provide a higher solubility for various compounds, nonetheless commonly associated with separations with lower efficiency.

Flow Characteristics

The interesting flow characteristics associated with the ZIC®-HILIC column distinguish it furthermore from other HILIC column brands. The figure on the right illustrates that optimal separation efficiency for Cytosine is obtained at 0.5 mL/min on a 4.6 mm I.D. column, a value that is half of the normal flow rate for other HILIC, and common reversed phase, columns. In addition, the ZIC®-HILIC column has an extreme flow rate working range. The two figures on the right and below exemplifie that a separation of Toluene (void volume marker), Uracil and Cytosine is feasible to perform using flow rates between 0.1 to 5.0 mL/min, still within acceptable backpressure levels, which demonstrates its suitability for high throughput separations as well.

By taking advantage of the weak electrostatic interactions between the analytes and the overall neutral zwitterionic ZIC®-HILIC stationary phase and carrying out proper tuning of the mobile phase, with respect to organic modifier, buffer salt, ionic strength, and pH, the column exhibits a unique selectivity in the analysis of a wide range of compounds. Combined with the advantageous column flow characteristics, a wide range of applications, from of high throughput to preparative scale separations can be performed.

Separation efficiency (closed diamonds) and column back pressure (open squares) as a function of volumetric flow rate for a 50 x 4.6 mm ZIC®-HILIC column with an eluent containing 80% acetonitrile in water.

Overlaid chromatograms showing the separation of toluene (void volume marker) uracil and cytosine at different flow-rates.

Analytical and Semi-Preparative Columns

Column Type

Particle Size

Pore Size

Length

ID

Pack of

Product No.
Analytical Column 5 µm 200 Å 50 mm 2.1 mm 1 pcs. 8SQ2712-052
5 µm 200 Å 100 mm 2.1 mm 1 pcs. 8SC2712-102
5 µm 200 Å 150 mm 2.1 mm 1 pcs. 8SQ2712-152
5 µm 200 Å 250 mm 2.1 mm 1 pcs. 8SQ2712-252
5 µm 200 Å 50 mm 4.6 mm 1 pcs. 8SQ2712-055
5 µm 200 Å 100 mm 4.6 mm 1 pcs. 8SQ2712-105
5 µm 200 Å 150 mm 4.6 mm 1 pcs. 8SQ2712-155
5 µm 200 Å 250 mm 4.6 mm 1 pcs. 8SQ2712-255
Semi-Preperative 5 µm 200 Å 50 mm 7.5 mm 1 pcs. 8SQ2712-058
Column
5 µm 200 Å 100 mm 7.5 mm 1 pcs. 8SQ2712-108
5 µm 200 Å 150 mm 7.5 mm 1 pcs. 8SQ2712-158
5 µm 200 Å 250 mm 7.5 mm 1 pcs. 8SQ2712-258

Capillary and Microbore Columns

Column Type

Particle Size

Pore Size

Length

ID

Pack of

Product No.
Capillary Column 3 µm 200 Å 30 mm 0.3 mm 1 pcs. 8SQ2902-030
5 µm 200 Å 30 mm 0.3 mm 1 pcs. 8SC2912-030
3 µm 200 Å 150 mm 0.3 mm 1 pcs. 8SQ2902-150
5 µm 200 Å 150 mm 0.3 mm 1 pcs. 8SQ2912-150
Guard Column 5 µm 200 Å 5 mm 0.3 mm 1 pcs. 8SQ2912-710
5 µm 200 Å 5 mm 0.3 mm 5 pcs. 8SQ2912-750
Microbore Column 3 µm 200 Å 30 mm 1.0 mm 1 pcs. 8SQ2902-031
5 µm 200 Å 30 mm 1.0 mm 1 pcs. 8SQ2912-031
3 µm 200 Å 150 mm 1.0 mm 1 pcs. 8SQ2912-151
5 µm 200 Å 150 mm 1.0 mm 1 pcs. 8SQ2912-151
Guard Column 5 µm 200 Å 5 mm 1.0 mm 1 pcs. 8SQ2912-711
5 µm 200 Å 5 mm 1.0 mm 5 pcs. 8SQ2912-751
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