NACALAI TESQUE, INC.

The reversed phase HPLC column is most commonly used because of the high theoretical plate number, excellent separation characteristics, reproducibility, affordable cost and ease of use. Columns packed with the octadecyl group bonded type silica gel (C₁₈, ODS) are the most widely employed. We offer three types of octadecyl group bonded columns: COSMOSIL C₁₈-MS-II, C₁₈-AR-II and C₁₈-PAQ, each of which has a different separation property.

Material characteristics

Packing material	C18-MS-II	C18-AR-II	C18-PAQ
Silica gel	high purity porous spherical silica
Average particle size	3 5 15 m		5 15 m
Average pore size	approx. 120
Specific surface area	approx. 300 m2/g
Stationary phase
	octadecyl group
Bonding type	monomeric	polymeric
Main interaction	hydrophobic interaction
End capping treatment	near-perfect treatment
Carbon content	approx. 16%	approx. 17%	approx. 11%
pH range	2-10*	1.5-7.5*	2-7.5
Feature	This phase is recommended for most applications but particularly effective for basic compounds.	This phase is recommended for separations requiring acidic mobile phase conditions. It also shows superior molecular shape selectivity to monomeric type C18columns.	This phase is designed to offer superior retention of polar compounds and excellent reproducibility in highly aqueous mobile phases, even in 100% aqueous.

Optimum pH range of columns based on silica gel is between 2 and 7.5.

Deference of separation property

Condition
Column size	4.6 mm I.D. x 150 mm	Sample	1. Valerophenone	(0.17 g)
Mobile phase	methanol : water = 80 : 20		2. Butyl Benzoate	(0.17 g)
Flow rate	1.0 ml/min		3. Butylbenzene	(8.0 g)
Temperature	30°C		4.o-Terphenyl	(0.17 g)
Detection	UV 254 nm		5. Amylbenzene	(8.0 g)
			6. Triphenylene	(0.021 g)

Column selection based on application data

We prepare following application data to help you select separation conditions.

COSMOSIL Chromatogram Index

More than 5,700 single compound elution profiles with full chromatographic condition description are available. They are not only an incredible help for chromatographers, but also can be used as references in choosing conditions for similar compounds. These data are available at our web site, please click here; Chromatogram Index.

COSMOSIL Application Data

COSMOSIL Application Data is now available on our website. The online version includes more than 1,000 application data using COSMOSIL columns. The online data are searchable by name of sample and column. If you have any questions regarding the application data or separations of compounds not listed here, please feel free to e-mail us.

Application data of substances in Japanese Pharmacopoeia, 15th version (222 data)

We prepare data of drugs using three kinds of C₁₈ columns that are specified in HPLC analysis in Application Data of Substances in Japanese Pharmacopoeia, 15th version. please click here.

Column selection by mobile phase

• If a mobile phase is determined, use the following chart to select an appropriate COSMOSIL column.
• Refer to application data above for choosing a mobile phase of new analysis.
• Adjustment of pH is required for dissociative compounds.
• Generally acidic mobile phase is suitable for acidic compounds, and neutral mobile phase is suitable for basic compounds.
• If you are not sure about the mobile phase, try C₁₈-MS-II first.

• COSMOSIL 5C₁₈-MS-II
• COSMOSIL 5C₁₈-AR-II
• COSMOSIL 5C₁₈-PAQ