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); andmeans (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.The invention has the
advantage of allowing effective separation of the compounds of the fluid to be chromatographed while ensuring that the bed is protected.