Abstract: The invention relates to a chromatography device comprising: a column (12) intended to house, between its two ends (16a, 16b) a chromatographic bed (14) and a fluid to be chromatographed, a fluid layer (48) being defined between a surface of the bed (14) and one (16a) of the ends of the column (12); a piston (36) sliding in the column (12), the piston (36) being one of the ends (16a, 16b) of the column (12); at least a first probe (45, 46) for detecting the surface of the bed (14), the probe (45, 46) being mounted on the end (16a) of the column (12) defining the layer (48); and means (52) for adjusting the position of the piston (36) according to the detection of the surface of the bed (14) by the probe (45, 46). The invention also relates to processes for separating at least two compounds of a fluid to be chromatographed and to methods of adjusting the position of the piston with respect to the surface of the chromatographic bed using the chromatography device.

Abstract: The invention concerns a chromatographic device including a column (12) for receiving a chromatographic bed (14) through which flow a first fluid; a piston (36) sliding inside the column (12) an exerting pressure on the bed (14), a chamber (28) containing a second fluid exerting pressure on the piston (36); a regulator (52) for the pressure exerted by the piston (36) on the bed based on the pressure inside the chamber (28), on the flow pressure on the first fluid at the intake of the column (12) and on a reference pressure of the bed (14). Said device enables to separate at least two compounds to be subjected to chromatographic analysis, while adjusting the pressure exerted on the chromatographic bed. The device efficiently uses the chromatographic bed while protecting it.

Abstract: The present invention is directed to a process for the isolation of (R)-tofisopam with high enantiomeric purity and high overall yields from a mixture of tofisopam enantiomers by means of a non-steady state continuous chromatographic process.

Abstract: The present invention is directed to a process for the isolation of the enantiomeric forms of modafinil with high enantiomeric purity and high overall yields by means of a continuous chromatographic process.

Abstract: The invention relates to a chromatography device comprising: a column (12) intended to house, between its two ends (16a, 16b) a chromatographic bed (14) and a fluid to be chromatographed, a fluid layer (48) being defined between a surface of the bed (14) and one (16a) of the ends of the column (12); a piston (36) sliding in the column (12), the piston (36) being one of the ends (16a, 16b) of the column (12); at least a first probe (45, 46) for detecting the surface of the bed (14), the probe (45, 46) being mounted on the end (16a) of the column (12) defining the layer (48); and means (52) for adjusting the position of the piston (36) according to the detection of the surface of the bed (14) by the probe (45, 46). The invention also relates to processes for separating at least two compounds of a fluid to be chromatographed and to methods of adjusting the position of the piston with respect to the surface of the chromatographic bed using the chromatography device.

Abstract: The invention relates to a chromatography device comprising: a column (12) intended to house, between its two ends (16a, 16b) a chromatographic bed (14) and a fluid to be chromatographed, a fluid layer (48) being defined between a surface of the bed (14) and one (16a) of the ends of the column (12); a piston (36) sliding in the column (12), the piston (36) being one of the ends (16a, 16b) of the column (12); at least a first probe (45, 46) for detecting the surface of the bed (14), the probe (45, 46) being mounted on the end (16a) of the column (12) defining the layer (48); and means (52) for adjusting the position of the piston (36) according to the detection of the surface of the bed (14) by the probe (45, 46). The invention also relates to processes for separating at least two compounds of a fluid to be chromatographed and to methods of adjusting the position of the piston with respect to the surface of the chromatographic bed using the chromatography device.

Abstract: The invention concerns a chromatographic device comprising: a column (12) for receiving a chromatographic bed (14) through which flows a first fluid; a piston (36) sliding inside the column (12) and exerting pressure on the bed (14), a chamber (28) containing a second fluid exerting pressure on the piston (36); a regulator (52) for the pressure exerted by the piston (36) on the bed based on the pressure inside the chamber (28), on the flow pressure of the first fluid at the intake of the column (12) and on a reference pressure on the bed (14). Said device enables to separate at least two compounds to be subjected to chromatographic analysis, while adjusting the pressure exerted on the chromatographic bed. The device efficiently uses the chromatographic bed while protecting it.

Abstract: The invention relates to a chromatography device comprising:

Abstract: Process for controlling the pressure in a separation system comprising a loop including several zones defined by fluid injection and fluid draw-off points is disclosed. A parameter such as the pressure is controlled at least at one point of the loop by acting on the global difference (.delta.) between the flow rates of fluids injected and the flow rates of fluids drawn off by means of well-determined variations (.delta..sub.X) applied to at least two injected and/or drawn off flows rates. This control is performed for example by imposing on each of these flow rates, variations (.delta..sub.X) depending on the respective values of these flow rates, and for example variations proportional to the respective values (X) of these flow rates. It is for example possible to maintain one or two of the flow rates of fluids injected and drawn off constant. The process can be applied for separating aromatic hydrocarbons or optical isomers for example.