Liquid Chromatography Format & Terminologies

This blog is part of our separation science primer series which provides an easy-to-understand overview of key topics in solid-phase extraction (SPE) and liquid chromatography (LC).

This blog focuses on liquid chromatography (LC) formats and terminologies used by us while describing our products, and processes. Similar formats and terminologies may be used by other scientists and vendors.

Liquid chromatography (LC) , is a separation technique that utilizes chromatographic stationary phase material (media). LC devices (columns), packed with the media, are available in various formats. Different names are used to describe the LC devices for each format.

1. Standard powder-packed LC. These are devices comprising of spherical microbeads packed between two polymeric frits within stainless steel or polymeric columns. Depending on the type of media, high (several thousand psi), medium (hundreds of psi), or low (tens of psi) packing pressure is applied to pack the column. The column's internal diameters can be units of millimeters to units of meters). The lengths of these columns can vary from tens of millimeters to tens of centimeters.
   

2. Capillary powder packed LC. These are devices comprising spherical microbeads packed between two polymeric frits within a capillary column. The capillary column is typically made of fused silica. Depending on the type of media, medium to high (several hundred to thousand psi) packing pressure is applied to pack the column. The column's internal diameters can be tens to hundreds of micrometers. The lengths of these columns can vary from tens of millimeters to tens of centimeters.
   

3. Monolith LC. Here the column is packed with a continuous three-dimensional network to form a single porous structure (monolith) instead of free flowing powder. Monoliths can be packed with stainless steel, polymeric, or capillary columns.

Additional terminologies that could be used to describe an LC device depending on how they are used in the workflow are:

1. Analytical LC. Analytical LC is used in discovery R&D and quality control to separate and characterize a mixture of compounds.
   

2. Flash. Flash LC is often used as a sample processing step to fractionate and pre-purify large sample quantities.
   

3. Semi-Preparative & Preparative LC. This process is often used to purify large sample quantities. Here a higher column pressure is used to achieve separation compared to low to medium pressure used in flash chromatography.
   

4. Fast protein LC (FPLC) is a type of preparative chromatography developed to meet the unique requirements in the purification of large biomolecules such as proteins and nucleic acids. The separation of these biomolecules is affected by temperatures, pressures, or solvents. Thus, alternative approaches, different from traditional LC methods and systems are used for the separation of these biomolecules.

We offer a suite of LC products employing our award-winning NanoPak-C carbon microbeads.

These include:

1. NanoPak-C All Carbon Analytical LC Columns.

2. NanoPak-C All Carbon Capillary LC Columns.

3. NanoPak-C All Carbon Flash LC Columns.

4. NanoPak-C All Carbon Semi-Preparative & Preparative LC Columns.

Custom products across these formats are also available.

Visit our store at www.millennialscientific.com/shop to learn more.