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Application Notes:
The neurotransmitters dl-DOPA, creatinine, hydroxytryptophan (5-HTP), and serotonin are separated in less than 4 minutes on a short 50 mm Primesep 200 column. The HPLC separation uses a mobile phase of water, acetonitrile (MeCN, ACN) and trifluoroacetic acid (TFA) and UV detection at 250 nm. Ion-pair reagents were not needed for retention of these polar, hydrophilic compounds, instead a combination of ion-exchange and reversed-phase interactions were used.
Application Columns:
- Primesep® 200 is a mixed-mode HPLC column with general hydrophobic and ion-exchange properties. The Primesep 200 stationary phase combines a hydrophobic chain and a weakly acidic functional group as a cation exchanger. Acids, bases, zwitterions and neutrals can be retained and separated by Primesep 200 columns. Primesep 200 retains hydrophobic compounds by reversed-phase retention alone or a combination of reversed-phase and ion-exchange retention. Primesep 200 separates underivatized amino acids, amines, isomers and structurally related compounds by combining reversed phase and ion exchange. In this case the acidic functional group acts as an embedded ion-pairing reagent. Organic acids and diacids are separated by reversed phase and ion exclusion. Methods can be developed on Primesep columns that are fully compatible with detectors such as UV, RI, conductivity, fluorescence, evaporative light scattering (ELSD) as well as mass spectrometers (LC/MS) and preparative chromatography (prep HPLC) systems.
Application Analytes:
Application Detection:
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Application Notes:
Primesep 200 separates catecholamines in the catecholamine pathway in 10 minutes. Phenylalanine, tyrosine, DOPA, dopamine, norepinephrine, and epinephrine are baseline resolved by a combination of reversed-phase, ion-exchange, and ion-exclusion mechanisms. Excellent peak shape results with a mass spec compatible mobile phase of water, acetonitrile (MeCN, ACN) and trifluoracetic acid (TFA) with UV detection at 210 nm.
Application Columns:
- Primesep® 200 is a mixed-mode HPLC column with general hydrophobic and ion-exchange properties. The Primesep 200 stationary phase combines a hydrophobic chain and a weakly acidic functional group as a cation exchanger. Acids, bases, zwitterions and neutrals can be retained and separated by Primesep 200 columns. Primesep 200 retains hydrophobic compounds by reversed-phase retention alone or a combination of reversed-phase and ion-exchange retention. Primesep 200 separates underivatized amino acids, amines, isomers and structurally related compounds by combining reversed phase and ion exchange. In this case the acidic functional group acts as an embedded ion-pairing reagent. Organic acids and diacids are separated by reversed phase and ion exclusion. Methods can be developed on Primesep columns that are fully compatible with detectors such as UV, RI, conductivity, fluorescence, evaporative light scattering (ELSD) as well as mass spectrometers (LC/MS) and preparative chromatography (prep HPLC) systems.
Application Analytes:
Application Detection:
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Bufferless Ion Separation (BLIS™) Chromatography of Amino Acids (1) |
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Application Notes:
Application Columns:
- Primesep® 200 is a mixed-mode HPLC column with general hydrophobic and ion-exchange properties. The Primesep 200 stationary phase combines a hydrophobic chain and a weakly acidic functional group as a cation exchanger. Acids, bases, zwitterions and neutrals can be retained and separated by Primesep 200 columns. Primesep 200 retains hydrophobic compounds by reversed-phase retention alone or a combination of reversed-phase and ion-exchange retention. Primesep 200 separates underivatized amino acids, amines, isomers and structurally related compounds by combining reversed phase and ion exchange. In this case the acidic functional group acts as an embedded ion-pairing reagent. Organic acids and diacids are separated by reversed phase and ion exclusion. Methods can be developed on Primesep columns that are fully compatible with detectors such as UV, RI, conductivity, fluorescence, evaporative light scattering (ELSD) as well as mass spectrometers (LC/MS) and preparative chromatography (prep HPLC) systems.
Application Analytes:
Application Detection:
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HPLC Separation of Compounds of Catecholamine Pathway |
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Application Notes:
The catecholamine neurotransmitters are amino acid derivatives of tyrosine. DOPA, tyrosine, phenylalanine, norepinephrine, epinephrine, and dopamine and baseline resolved on a Primesep 200 column. The HPLC separation uses a mobile phase of water, acetonitrile (MeCN, ACN), trifluoracetic acid (TFA) or ammonium formate and ultraviolet (UV) detection at 210 nm. Peak order and retention time can be changed by switching from TFA to ammonium formate in the mobile phase.
Application Columns:
- Primesep® 200 is a mixed-mode HPLC column with general hydrophobic and ion-exchange properties. The Primesep 200 stationary phase combines a hydrophobic chain and a weakly acidic functional group as a cation exchanger. Acids, bases, zwitterions and neutrals can be retained and separated by Primesep 200 columns. Primesep 200 retains hydrophobic compounds by reversed-phase retention alone or a combination of reversed-phase and ion-exchange retention. Primesep 200 separates underivatized amino acids, amines, isomers and structurally related compounds by combining reversed phase and ion exchange. In this case the acidic functional group acts as an embedded ion-pairing reagent. Organic acids and diacids are separated by reversed phase and ion exclusion. Methods can be developed on Primesep columns that are fully compatible with detectors such as UV, RI, conductivity, fluorescence, evaporative light scattering (ELSD) as well as mass spectrometers (LC/MS) and preparative chromatography (prep HPLC) systems.
Application Analytes:
Application Detection:
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HPLC Separation of Polar and Hydrophobic Drugs on Obelisc R and N |
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Application Notes:
Application Columns:
- Obelisc N columns are the first commercially available columns with Liquid Separation Cell technology (LiSC). With multiple patents pending, LiSC technology is based on a new chemical modification of silica gel pores that creates a liquid separation cell with its own charge characteristics, ionic strength, and hydrophobic properties. Like living cells which exist in equilibrium with the outside environment, liquid separation cells exist in constant equilibrium with the mobile phase. Obelisc N, for normal phase, has very polar characteristics and works well for polar and charged analytes. In ion-exchange mode, charged analytes interact with oppositely charged groups on the stationary phase. In traditional HILIC mode, a charged or neutral polar analyte interacts with a water layer on the polar stationary phase surface. On Obelisc N the charges are greatly separated and independently accessible which results in different selectivity compared to traditional HILIC and silica columns. Mobile phase composition changes the conformation of the long hydrophilic chain. This affects the properties of the liquid separation cell and changes separation selectivity. Typical mobile phases used with Obelisc N columns are based on acetonitrile, water, and the mass spec compatible buffers ammonium formate (pH 3) and ammonium acetate (pH 5). If it is necessary to detect in low UV (<220 nm) then phosphate buffer is recommended. Obelisc N columns are compatible with mass spectrometers (LC/MS), evaporative light scattering detectors and preparative chromatography (prep HPLC) system.
- Obelisc R columns are the first commercially available columns with Liquid Separation Cell technology (LiSC). With multiple patents pending, LiSC technology is based on a new chemical modification of silica gel pores that creates a liquid separation cell with its own charge characteristics, ionic strength, and hydrophobic properties. Like living cells which exist in equilibrium with the outside environment, liquid separation cells exist in constant equilibrium with the mobile phase. Obelisc R, for reversed phase, has reversed-phase character and can be used in traditional, reversed-phase type applications. Due to the presence of ionic groups and a long hydrophobic chain, Obelisc R offers additional retention and tuning that is not available with traditional reversed-phase columns. Reversed-phase separations are augmented by additional ionic and polar interactions not available on traditional reversed-phase C18 columns. Mobile phase composition changes the conformation of the long hydrophobic chain and affects the properties of the liquid separation cell and changes separation selectivity. Typical mobile phases used with Obelisc R columns are based on acetonitrile, water, and the mass spec compatible buffers ammonium formate (pH 3) and ammonium acetate (pH 5). If it is necessary to detect in low UV (<220 nm) then phosphate buffer is recommended. Obelisc R columns are compatible with mass spectrometers (LC/MS), evaporative light scattering detectors and preparative chromatography (prep HPLC) systems.
Application Analytes:
Application Detection:
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