| |
Control of Cation Exchange Properties by pH of Primesep C Column |
 |
Application Notes:
Primesep C demonstrates the control of ion-exchange properties of Primesep columns. The peak order of caffeine and benzylamine in a mixture of caffeine, benzylamine, and phenol reverses when the mobile phase modifier is changed from ammonium acetate to trifluoroacetic acid. Control of the separation is possible even with mass spec (LC/MS) compatible mobile phases of water, acetonitrile (MeCN, ACN) and ammonium acetate or trifluoroacetic acid (TFA).
Application Columns:
- Primesep® C is a mixed-mode HPLC column with reversed-phase, ion-exchange and host-guest complex formation properties. The Primesep C stationary phase combines a hydrophobic chain and an acidic functional group as a cation exchanger. Acids, bases, and neutrals can be retained and separated by Primesep 100 columns. Primesep C retains hydrophobic compounds by a reversed phase. Strongly polar and basic compounds such as quaternary amines are retained without the use of ion-pairing reagent by reversed phase and ion exchange. An unusual elution order compared to other HPLC columns is found for primary, secondary, and tertiary amines. 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:
|
HPLC Separation of Coffee |
 |
Application Notes:
The amount of caffeine in regular and decaffeinated coffee can be determined using a Primesep SB column. The HPLC method combines reversed-phase and polar interactions to elute caffeine without interference from the coffee complex mixture. This method can be made even more robust by incorporating a diverter valve and a guard column to prevent late eluting components from sticking to the Primesep SB column. The sample is injected onto the guard column and after a defined time point, the eluent flow is reversed to elute the caffeine peak onto the analytical column without the late eluters that can shorten column life. The HPLC separation uses a mobile phase of water, methanol (MeOH) and phosphoric acid (H3PO4) and UV detection at 270 nm.
Application Columns:
- Primesep® SB is a mixed-mode HPLC column with general hydrophobic and ion-exchange properties. The Primesep SB stationary phase combines a hydrophobic chain and a strongly basic functional group as an anion exchanger. Acids, bases, zwitterions and neutrals can be retained and separated by Primesep SB columns. Primesep SB is ideal to retain hydrophobic compounds by reversed-phase retention due to its C18 carbon chain. Basic hydrophobic compounds are usually retained less on Primesep SB columns than on similar RP columns due to a charge repulsion effect. Primesep SB also separates bases by an ion-exclusion mechanism. Primesep SB demonstrates significant improvement in retention and selectivity for the separation of weak acid analytes by a combination of reversed phase and anion exchange. In this case the basic functional group acts as an embedded ion-pairing reagent. Primesep SB column is one of the best separation media for natural product extracts. 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:
|
HPLC Analysis of Active Drug in a Formulation |
 |
Application Notes:
Application Columns:
- 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:
|
HPLC Separation of Caffeine and Phenylephrine |
 |
Application Notes:
Application Columns:
- Primesep® 100 is a mixed-mode HPLC column with general hydrophobic and ion-exchange properties. The Primesep 100 stationary phase combines a hydrophobic chain and an acidic functional group as a cation exchanger. Acids, bases, zwitterions and neutrals can be retained and separated by Primesep 100 columns. Primesep 100 retains hydrophobic compounds by reversed-phase retention alone or a combination of reversed-phase and ion-exchange retention. Primesep 100 separates underivatized amino acids and amines by combining reversed-phase and ion-exchange mechanisms. In this case the acidic functional group acts as an embedded ion-pairing reagent. Organic acids are separated by reversed phase and ion exclusion. Inorganic cations can be separated by cation exchange. 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.
- 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:
|
|
|
