A chromatography system comprising at least two pumps, a first pump which is connectable or connected with a liquid reservoir for a first fluid, and a second pump which is connectable or connected with a liquid reservoir for a second fluid, wherein the pump outlet lines from the first pump and the second pump are connected with a connection piece and, viewed in the direction of flow, a chromatography column is provided downstream of this connection piece, wherein, viewed in the direction of flow, an addition unit is provided upstream of the connection piece and a mixer switching valve and a mixer switchable by way of the mixer switching valve are provided between the connection piece and chromatography column, wherein the mixer switching valve has at least two switching positions, wherein the mixer is connectable in a first position and the mixer is bypassable in a second position.

A chromatography method in which the system is used and a conversion kit for converting a high-performance liquid chromatography system into a chromatography system for supercritical fluid chromatography are also disclosed.

A chromatography system comprising at least two pumps, a first pump which is connectable or connected with a liquid reservoir for a first fluid, and a second pump which is connectable or connected with a liquid reservoir for a second fluid, wherein the pump outlet lines from the first pump and the second pump are connected with a connection piece and, viewed in the direction of flow, a chromatography column is provided downstream of this connection piece, wherein, viewed in the direction of flow, an addition unit is provided upstream of the connection piece and a mixer switching valve and a mixer switchable by way of the mixer switching valve are provided between the connection piece and chromatography column, wherein the mixer switching valve has at least two switching positions, wherein the mixer is connectable in a first position and the mixer is bypassable in a second position.

A chromatography method in which the system is used and a conversion kit for converting a high-performance liquid chromatography system into a chromatography system for supercritical fluid chromatography are also disclosed.

A gas chromatograph is provided with: a sample gas generator; a separation column; a detector; a plurality of gas supply sources; a switching unit; a regulator-; and an out-of-gas determination unit. After the out of gas determination unit has determined that the out of gas has occurred in the gas supply source supplying the carrier gas to the sample gas generator, it is configured to perform a column protection operation for changing the gas supply source fluidly connected to the sample gas generator by the switching unit.

A gas chromatograph is provided with: a sample gas generator; a separation column; a detector; a plurality of gas supply sources; a switching unit; a regulator-; and an out-of-gas determination unit. After the out of gas determination unit has determined that the out of gas has occurred in the gas supply source supplying the carrier gas to the sample gas generator, it is configured to perform a column protection operation for changing the gas supply source fluidly connected to the sample gas generator by the switching unit.

A sample injector for use in a fluid separation system for separating compounds of a fluidic sample in a mobile phase, the sample injector comprising a switchable valve, a sample loop in fluid communication with the valve and configured for receiving the fluidic sample, a metering device in fluid communication with the sample loop and configured for introducing a metered amount of the fluidic sample on the sample loop, and a control unit configured for controlling switching of the valve to transfer the sample loop between a low pressure state and a high pressure state via an intermediate state and for controlling the metering device during the intermediate state to at least partially equilibrate a pressure difference in the sample loop between the low pressure state and the high pressure state.

A sample injector for use in a fluid separation system for separating compounds of a fluidic sample in a mobile phase, the sample injector comprising a switchable valve, a sample loop in fluid communication with the valve and configured for receiving the fluidic sample, a metering device in fluid communication with the sample loop and configured for introducing a metered amount of the fluidic sample on the sample loop, and a control unit configured for controlling switching of the valve to transfer the sample loop between a low pressure state and a high pressure state via an intermediate state and for controlling the metering device during the intermediate state to at least partially equilibrate a pressure difference in the sample loop between the low pressure state and the high pressure state.

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.

Injector (40) for injecting a fluidic sample into a mobile phase in a sample separation apparatus (10), the injector (40) comprising a main flow path (100) between a fluid drive (20) and a sample separation device (30), wherein the fluid drive (20) is adapted to drive the mobile phase and the sample separation device (30) is adapted to separate the fluidic sample that is injected into the mobile phase, a discharge device (104) for discharging an, in particular predetermined, amount of the mobile phase from the main flow path (100), and a supply device (102) for supplying an, in particular predetermined, amount of the fluidic sample and/or of a solvent into the main flow path (100), wherein the discharged amount and the supplied amount compensate each other at least partially.

Injector (40) for injecting a fluidic sample into a mobile phase in a sample separation apparatus (10), the injector (40) comprising a main flow path (100) between a fluid drive (20) and a sample separation device (30), wherein the fluid drive (20) is adapted to drive the mobile phase and the sample separation device (30) is adapted to separate the fluidic sample that is injected into the mobile phase, a discharge device (104) for discharging an, in particular predetermined, amount of the mobile phase from the main flow path (100), and a supply device (102) for supplying an, in particular predetermined, amount of the fluidic sample and/or of a solvent into the main flow path (100), wherein the discharged amount and the supplied amount compensate each other at least partially.