| |
Complex Mixture of Acids, Bases, Amino Acids, and Neutral Compounds |
 |
Application Notes:
Primesep 100 separates a mixture of amino acids (tyrosine, phenylalanine), organic acids (benzoic acid, mandelic acid), amines (benzylamine, pyridine), and neutrals (benzonitrile, toluene) in one HPLC run by combining reversed-phase, cation-exchange, and polar interactions. The method is tunable and peak order can be changed significantly by adjusting acetonitrile and trifluoroacetic acid concentrations. The separation method uses a mobile phase mixture of water, acetonitrile (MeCN, ACN) and trifluoracetic acid (TFA) and compatible with UV, mass spec (LC/MS) and evaporative light scattering (ELSD) detection.
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.
Application Analytes:
Application Detection:
|
HILIC Separation of Carboxylic Acids |
 |
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.
Application Analytes:
Application Detection:
|
|
|
