Specifications

Packing Material	HILIC
USP Code	L104
Silica Gel	High Purity Porous Spherical Silica
Average Particle Size	5 µm
Average Pore Size	approx. 120Å
Specific Surface Area	approx. 300 m2/g
Stationary Phase
Interactions	Hydrophilic Interaction, Anion Exchange
Suitable Samples	Hydrophilic Compounds, Acidic Compounds
Features	Suitable for non-retaining by C18

Comparison with C₁₈

Hydrophilic interaction chromatography is a variation of normal phase chromatography in which a polar stationary phase is used with a mobile phase that contains a high concentration of water-miscible organic solvent and a low concentration of aqueous eluent. The main retention mechanism is the partitioning of the polar analytes between the polar stationary and the non-polar mobile phase. As it is also called "aqueous normal phase," the elution order is similar to that of normal phase and the sample elution is in the order of increasing hydrophilicity. Without using ion-pair reagents, COSMOSIL HILIC retains highly polar analytes that would not be retained in reversed phase chromatography. It also shows a weak anion-exchange mechanism with the positively charged stationary phase; thus acidic compounds are strongly retained.

COSMOSIL HILIC	COSMOSIL 5C18-PAQ

Melamine Related Compunds

BCAA (branched-chain amino acids)

Optimizing Analytical Conditions

The COSMOSIL HILIC Chromatogram Index, which includes 167 chromatograms using COSMOSIL HILIC, is available. This index is a useful tool for all chromatographers, assisting them in optimizing analytical conditions for hydrophilic interaction chromatography.

Column	5 µm HILIC
I.D. (mm)	2.0	3.0	4.6	10.0	20.0
Washing method	Remove buffer, salts and/or acid from column: wash for 10-15 min. using the mobile phase last used, without buffer, salts or acid. For example, if your mobile phase was 50:50 acetonitrile/20 mmol/l phosphate buffer, wash with 50:50 acetonitrile/water. Remove adsorbed compounds and fix unstable baselines: Wash with 50:50 acetonitrile/water or up to 100% water.
Storage conditions	Remove buffer, salts and/or acid from column: wash for 10-15 min. using the mobile phase last used, without buffer, salts or acid. Then, replace the solvent with 90:10 acetonitrile/water. Tightly plug the column, and store in a cool and dry place.
Usable pH range	pH 2–7.5
Max. pressure	20MPa			15MPa
Temperature range	The maximum usable temperature is 60°C. However. for regular use, please use at a constant temperature between 20°C and 50°C.
Usable solvents	Acetonitrile/water mobile phases are recommended.
Other instructions	Retention increases with increased acetonitrile concentration. Acetonitrile concentration should be within 0–95% (usually 50–95%). Retention will decrease when using methanol/water mobile phases. Only use HPLC-grade solvents. It is necessary to use salts or buffers for dissociating compounds. However, these have low solubility in the high-organic mobile phases used in HILIC mode. Phosphate buffers, widely used in reversed-phase, are not suitable for HILIC for this reason. When using salts or buffers, the acetonitrile concentration should be 70% or less. Before use, please confirm that the additives are completely soluble in the mobile phase. Neutral pH will maximize retention time.

Brochures

• COSMOSIL HILIC (1.1 MB)
• COSMOSIL HILIC Application Notebook (18.5 MB)
• Melamine Analysis (0.4 MB)

Posters

• Simultaneous separation of pharmaceutical substances and counterions using a serial connection of hydrophilic interaction and reversed phase columns
  (Poster from HPLC 2010, Boston, MA, USA)
  (0.2 MB)

Reference list

• COSMOSIL HILIC reference list