What does normal phase mean in HPLC?

Published by Charlie Davidson on

What does normal phase mean in HPLC?

In normal-phase chromatography, the mobile phase is 100% organic. Only traces of water are present in the mobile phase and in the pores of the polar packing particles. Polar analytes bind strongly to the polar stationary phase and may not elute.

What is normal phase of chromatography?

Normal-phase liquid chromatography (NPLC) is a technique that uses columns packed with polar stationaryphases combined with nonpolar or moderately-polar mobile phases to separate the components of mixtures. The rate at which individual solutes migrate through NPLC columns is primarily a function of their polarity.

What is normal phase HPLC used for?

Normal phase chromatography, an adsorptive mechanism, is used for the analysis of solutes readily soluble in organic solvents, based on their polar differences such as amines, acids, metal complexes, etc.. Reversed-phase chromatography, a partition mechanism, is typically used for separations by non-polar differences.

What is the principle of HPLC chromatography?

The separation principle of HPLC is based on the distribution of the analyte (sample) between a mobile phase (eluent) and a stationary phase (packing material of the column). Depending on the chemical structure of the analyte, the molecules are retarded while passing the stationary phase.

Is silica polar or nonpolar?

The stationary phase i.e. silica is very polar in nature, while the solvent is less polar compared to silica.

Is C18 polar or nonpolar?

A C18 column is an example of a “reverse phase” column. Reverse phase columns are often used with more polar solvents such as water, methanol or acetonitrile. The stationary phase is a nonpolar hydrocarbon, whereas the mobile phase is a polar liquid.

What is the mobile phase in HPLC?

Sample carried by a moving gas stream of Helium or Nitrogen. High Performance Liquid Chromatography (HPLC) is a form of column chromatography that pumps a sample mixture or analyte in a solvent (known as the mobile phase) at high pressure through a column with chromatographic packing material (stationary phase).

Why assay is more than 100?

If the purity of a product, especially in pharma is 99.99% and if you estimate the assay by any analytical method you may get a value exceeding 100%. This is due to the contribution of type A and type B measurement uncertainties.

What are different types of HPLC?

HPLC analyses fall into four different categories: (1) reverse phase chromatography where the stationary phase is hydrophobic (C18-modified silica), (2) normal phase chromatography where the stationary phase is hydrophilic (silica), (3) hydrophilic interaction chromatography, a hybrid of techniques 1 and 2, and (4) ion …

Is the mobile phase polar or nonpolar?

Stationary phases are usually very polar, while mobile phases vary widely in polarity, but are less polar than the stationary phase. This is called normal phase (NP) chromatography.

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