Specifications

Packing Material	5PBr
Silica Gel	High purity porous spherical silica
Average Particle Size	5 µm
Average Pore Size	approx. 120 Å
Specific Surface Area	approx. 300 m2/g
Stationary Phase	Pentabromobenzyl group
Bonding Type	Monomeric
Endcapping treatment	Yes
Carbon load	approx. 8%
Usable pH range	2-7.5

Separation of hydrophilic compounds in reversed-phase conditions

Hydrophilic interaction chromatography (HILIC) is an increasingly popular analytical technique. However, it is often difficult to develop a robust method due to users’ less familiarity with HILIC conditions. Furthermore, high concentration of acetonitrile used in HILIC mobile phase makes it extremely sensitive to samples’ water concentration; injecting samples in high water concentration often results in poor peak shapes. COSMOSIL PBr enables separation of hydrophilic compounds in reversed phase conditions, maintaining sharp peak shapes even with aqueous samples.

Condition
Column size	4.6 mm I.D. x 150 mm	Sample	Uracil (0.1 mg/ml) Uridine (0.2 mg/ml)
Mobile phase	HILIC: Acetonitrile / H2O = 90/10 PBr:H2O
Flow Rate	1.0 ml/min	Sam. solution	H2O
Temperature	30°C
Detection	UV260nm

Comparison with C18 Columns

COSMOSIL PBr retains hydrophilic compounds stronger than C18 columns under the same reversed-phase conditions.

Condition
Column size	4.6 mm I.D.×250 mm	Sample	Ammelide (0.1 mg/ml) Cyanuric Acid (0.5 mg/ml) Ammeline (0.1 mg/ml) Melamine (0.1 mg/ml)
Mobile phase	20 mmol/l Phosphate Buffer(pH7.0)
Flow Rate	1.0 ml/min
Temperature	30°C
Detection	UV225nm	Inj. Vol.	1.0 ul

Separation Mechanism

In reversed-phase chromatography, compounds are separated by difference in hydrophobicity (the number of CH2 bases, see chromatogram on the left (1)). Compounds with little hydrophobicity (the number of OCH2CH2, see chromatogram on the right (2)), are not retained by a C18 column. However, these compounds can easily be separated by dispersion force interaction using the COSMOSIL PBr column.

Compounds with more hydrophobicity

Condition
Column size	4.6 mm I.D.×150 mm	Sample	Benzene Toluene Ethylbenzene n-Propylbenzene n-Butylbenzene
Mobile phase	Methanol/ H2O = 80/20
Flow rate	1.0 ml/min
Temperature	30°C
Detection	UV254nm

Compounds with less hydrophobicity

Condition
Column size	4.6 mm I.D.×150 mm	Sample	Benzyl Alcohol Ethylene Glycol Monobenzyl Ether Diethylene Glycol Monobenzyl Ether Triethylene Glycol Monobenzyl Ether Tetraethylene Glycol Monobenzyl Ether
Mobile phase	Methanol/ H2O = 60/40
Flow rate	1.0 ml/min
Temperature	30°C
Detection	UV254nm

Dispersion force (instantaneous dipole-induced dipole force)

London Dispersion force is a weak intermolecular force that results from dipoles temporarily induced from random unsymmetrical electron positions in two adjacent atoms, also known as "instantaneous dipole-induced dipole force". It is present in all molecules, regardless of whether they are polar or non-polar. Compounds with high polarizability have stronger dispersion force.

Compounds with stronger dispersion force

• Larger and heavier molecules
• Molecules with larger and heavier atoms (e.g. from weakest to strongest in halogens, F2, Cl2, Br2, and I2)
• Molecules with delocalized electrons and resonance (e.g. aromatic compounds)

COSMOSIL PBr column is packed with pentabromobenzyl bonded silica that enables separation by dispersion force interaction.

Suitable Compounds to Analyze by COSMOSIL PBr

COSMOSIL PBr retains cyclic compounds or amide compounds more strongly than C18 columns.

(Mobile phase)
(1) Methanol/ 20mmol/l Phosphate buffer(pH7.0) = 10/90
(2) 20mmol/l Phosphate buffer(pH2.5)
(3) 20mmol/l Phosphate buffer(pH7.0)
(4) Methanol/ H2O = 10/90

Column Stability Test

COSMOSIL PBr column remains stable after 1000 injections under 100% aqueous condition.

Condition
Column size	4.6 mm I.D. × 150 mm	Sample	L-Noradrenaline (0.5 mg/ml) L-Adrenaline (0.5 mg/ml) Dopamine (0.5 mg/ml) L-DOPA (0.5 mg/ml)
Mobile phase	20 mmol/l Phosphate buffer(pH2.5)
Flow rate	1.0 ml/min
Temperature	40°C
Detection	UV280nm	Inj.Vol.	1.0 µl

Raffinose and Stachyose

Condition
Column size	4.6 mm I.D. x 250 mm	Sample	1; Raffinose (5 mg/ml) 2; Stachyose (5 mg/ml)
Mobile phase	Methanol/ H2O = 5/95
Flow rate	1.0 ml/min
Temperature	30°C
Detection	RI	Inj.Vol.	2.0 µl

Gentamycin

Condition
Column size	4.6 mm I.D. x 150 mm	Sample	Gentamicin (C1a, C2, C2a, C1)
Mobile phase	0.1% Pentafluoropropionic Acid -Acetonitrile/ H2O = 10/90
Flow rate	0.2 ml/min
Temperature	40°C
Detection	ESI-MS, Positive, SIM	Inj.Vol.	1.0 µl

Nucleic Acid Base

Coenzyme A

Methylimidazole Isomers

Applications

Surfactants

COSMOSIL PBr shows excellent separation for surfactants compared to C18 or PFP columns.

Condition
Column size	4.6 mm I.D. x 150 mm	Sample	Triton(R) X-100 (50 mg/ml)
Mobile phase	5C18-MS-II, 5PFP: Methanol/ H2O = 80/20 PBr: Methanol
Flow rate	1.0 ml/min
Temperature	30°C
Detection	UV254nm	Inj.Vol.	2.0 µl

Halogen Compounds

COSMOSIL PBr shows high selectivity for halogen compounds.

Condition
Column size	4.6 mm I.D. x 150 mm	Sample	Fluorobenzene (1.0 mg/ml) α,α,α-Trifluorotoluene [Benzotrifluoride] (0.25 mg/ml) Toluene (2.5 mg/ml) Chlorobenzene (5.0 mg/ml) Bromobenzene (5.0 mg/ml) Iodobenzene (2.0 mg/ml)
Mobile phase	Methanol/ H2O = 65/35
Flow rate	1.0 ml/min
Temperature	30°C
Detection	UV254nm	Inj.Vol.	1.0 µl

See more COSMOSIL Applications

Brochures

• COSMOSIL PBr (1.4 MB)
• Polar molecule separation by COSMOSIL PBr(1.7 MB)
• LC-MS/MS Analysis of Monoamines in Mouse Brain Tissue (1 MB)

Posters

• Evaluation of Pentabromobenzyl Stationary Phase for Separation of Polar Compounds by Reversed-Phase Chromatography
  (Poster from HPLC 2015, Geneva)
  (370 KB)
• Fat-Soluble and Water-Soluble Vitamins in Functional Water
  (Poster from Food Science Asia 2015, Singapore)
  (870 KB)