The present invention provides methods for performing supercritical fluid chromatography comprising loading a sample to be separated by supercritical fluid chromatography onto a stationary phase comprising a spherical, monodisperse, core-shell particulate material comprising a nonporous core and one or more layers of a porous shell material surrounding the core, wherein the particles are sized less than 2 microns; and performing supercritical fluid chromatography to separate the sample.

The present invention provides methods for performing supercritical fluid chromatography comprising loading a sample to be separated by supercritical fluid chromatography onto a stationary phase comprising a spherical, monodisperse, core-shell particulate material comprising a nonporous core and one or more layers of a porous shell material surrounding the core, wherein the particles are sized less than 2 microns; and performing supercritical fluid chromatography to separate the sample.

The technology generally relates to tailoring a back pressure regulator in a chromatographic system to reduce unswept volume within the back pressure regulator to achieve better sample detection and a reduction in chromatographic band distortion effects.

The technology generally relates to tailoring a back pressure regulator in a chromatographic system to reduce unswept volume within the back pressure regulator to achieve better sample detection and a reduction in chromatographic band distortion effects.

A methodology scales supercritical fluid chromatography (SFC) and/or carbon dioxide based chromatography methods between different system and/or column configurations. The methodology includes measuring an average mobile phase density during a first separation utilizing C02 as a mobile phase component and substantially duplicating the average density profile for a second separation. Substantial duplication of the average mobile phase density (e.g., within about 10%, 5%, 2.5%, 1%, 0.5%, 0.1 %, 0.05%) results in chromatography for both system and/or column configurations having similar selectivity and retention factors. Average mobile phase density may be, either measured directly, calculated, or approximated using average pressure or density measurements. The average pressure profile may be used as a close approximation to duplicate average density profiles between separations.

A methodology scales supercritical fluid chromatography (SFC) and/or carbon dioxide based chromatography methods between different system and/or column configurations. The methodology includes measuring an average mobile phase density during a first separation utilizing C02 as a mobile phase component and substantially duplicating the average density profile for a second separation. Substantial duplication of the average mobile phase density (e.g., within about 10%, 5%, 2.5%, 1%, 0.5%, 0.1 %, 0.05%) results in chromatography for both system and/or column configurations having similar selectivity and retention factors. Average mobile phase density may be, either measured directly, calculated, or approximated using average pressure or density measurements. The average pressure profile may be used as a close approximation to duplicate average density profiles between separations.

The present invention relates to a gas-liquid separator for a chromatography system, comprising: a) a separating region having an inlet nozzle, a baffle unit and a gas distribution unit; (b) a dividing region having a liquid outlet; and (c) a gas discharge region having a gas outlet; wherein the separating region is connected to the dividing region by a separating opening and the distance of the inlet nozzle from the baffle unit is greater than the smallest longitudinal extension of the separating opening and the inlet nozzle is configured such that a gas-liquid stream directed through the inlet nozzle can act on the baffle unit. The present invention further relates to a chromatography system comprising a separator according to the invention and to a chromatography method wherein the separator is used.

The present invention relates to a gas-liquid separator for a chromatography system, comprising: a) a separating region having an inlet nozzle, a baffle unit and a gas distribution unit; (b) a dividing region having a liquid outlet; and (c) a gas discharge region having a gas outlet; wherein the separating region is connected to the dividing region by a separating opening and the distance of the inlet nozzle from the baffle unit is greater than the smallest longitudinal extension of the separating opening and the inlet nozzle is configured such that a gas-liquid stream directed through the inlet nozzle can act on the baffle unit. The present invention further relates to a chromatography system comprising a separator according to the invention and to a chromatography method wherein the separator is used.

When a liquid in the column is replaced by carbon dioxide in a supercritical state in the chromatograph, an operation of a first pump is controlled by a flow rate control unit, and the carbon dioxide in the supercritical state is supplied at a constant pressure. Moreover, when a flow rate of the carbon dioxide in the supercritical state reaches a predetermined flow rate thereafter, the flow rate control unit controls an operation of the first pump so that the carbon dioxide in the supercritical state is supplied at a constant flow rate.

When a liquid in the column is replaced by carbon dioxide in a supercritical state in the chromatograph, an operation of a first pump is controlled by a flow rate control unit, and the carbon dioxide in the supercritical state is supplied at a constant pressure. Moreover, when a flow rate of the carbon dioxide in the supercritical state reaches a predetermined flow rate thereafter, the flow rate control unit controls an operation of the first pump so that the carbon dioxide in the supercritical state is supplied at a constant flow rate.