DAC dynamic axial compression column filling steps

DAC dynamic axial compression columns adopt DAC dynamic axial compression technology to prevent bed collapse or eliminate the impact of bed collapse. Conventional axial compression technology is difficult to fill a chromatographic column with high column efficiency, so only dynamic axial compression technology can be used. DAC is recognized as the only technology that can maintain good separation effects in column chromatography of all sizes. It is also the most popular column packing technology in the field of preparative chromatography today. The advanced DAC dynamic axial compression preparatory column system can pack and maintain columns by itself. pressure, self-unloading, and has the functions of both a chromatographic column and a column packing machine

Stir the homogenized silica gel carefully again. Be sure to stir the silica gel that has settled at the bottom again, otherwise the silica gel may not be poured into the column.

Block the liquid outlet at the bottom of the column and open the liquid outlet at the top of the piston. The purpose of this is to prevent the solvent at the bottom from flowing out naturally. Pour the homogenized silica gel into the column tube, quickly install the piston, and start loading the column.

First, turn the air pressure regulating valve counterclockwise to the end and make sure the reversing valve is pointing to the "down" position

Then, turn the main air source switch to the "on" position and turn on the air source switch.

Secondly, pull out the pressure regulating valve cover and slowly rotate it clockwise until the pneumatic pump works. After the piston enters the column tube, observe the air pressure gauge and adjust the air pressure knob so that the pointer of the air pressure gauge reaches 4.5bar, corresponding to the numerical display of the hydraulic gauge. About 160bar.

Note: A solvent bottle must be placed in the liquid outflow pipe and held by hand to prevent the momentum of the high-speed discharge of the solvent from causing the pipe to jump and the solvent to splash. After the piston advances a certain distance downward, the piston begins to contact the silica gel and the top tube begins to discharge liquid. At this time, the bottom solvent outlet should be opened immediately and the upper inlet should be sealed; the purpose of this is to keep the liquid from being discharged only from the bottom. While the upper part of the column bed remains moist, as much pressure as possible is transmitted to the bottom. The piston continues to push down until it stops moving and liquid stops flowing out.

Then, take both tubes out of the solvent bottle and raise both ends above the top of the column tube. Maintain the column packing pressure and let it sit for 20 minutes. The purpose of this is to allow the internal stress of the silica gel to fully dissipate without hindrance, but not so that the solvent will slowly drain away.

The packed column is ready for the next step.