Low-retention pre-columns: a straightforward approach to enable larger injection volumes and reduce extra-column effects in HPLC
OwnerMark A. Stoneinventor
Life of this patent
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Abstract
Low-retention pre-columns that allow increased injection volumes of solvents chromatographically stronger than the mobile phase and use of solvents with limited solubility in the mobile phase, such as ethyl acetate and MTBE. The system and method also reduces band broadening due to the extra-column effects acting upstream of the analytical column, including band broadening due to the injection process and due to the connecting tubing and fittings between the injection system and the column. A pre-column may also be used as a guard column, thereby minimizing band broadening due to the guard column.
Claims13
A column liquid chromatography apparatus enabling larger injection volumes and minimizing extra column effects acting upstream of a column, comprising:
- an analytical column having a stationary phase with a head;
- a turbulent flow column in fluid communication with said analytical column and having a stationary phase for adsorbing and eluting analytes of a predetermined size;
- a focusing pre-column positioned between, and in fluid communication with, said turbulent flow column and said analytical column, and including a stationary phase that separates solutes from the molecules of an injection solvent and enables focusing of solutes onto said head of said analytical column;
- and
- a turbulent flow loop comprising a section of turbulent flow tubing in fluid communication with, and disposed between, said pre-column and the point at which a solvent is injected, said turbulent flow tubing configured and sized to cause turbulent flow of fluid through said turbulent flow loop.
A column liquid chromatography apparatus enabling larger injection volumes and minimizing extra column effects acting upstream of a column, comprising:
- an analytical column having a stationary phase with a head;
- a turbulent flow column in fluid communication with said analytical column and having a stationary phase for adsorbing and eluting analytes of a predetermined size;
- and
- a focusing pre-column positioned between, and in fluid communication with, said turbulent flow column and said analytical column, and including a stationary phase that separates solutes from the molecules of an injection solvent and enables focusing of solutes onto said head of said analytical column;
- wherein when used in a reversed phase mode said stationary phase of said focusing pre-column comprises particles of silica hydride to retain polar solutes in the presence of a non-polar solvent;
- and
- wherein said stationary phase of said focusing pre-column comprises silica hydride particles with a generally polar phase bonded to said silica hydride particles, thereby enabling said focusing pre-column to retain non-polar solutes.
Dependencies are inferred from the claim text.