Designing a metering pump, chromatography.

Hello.
I am in the process of designing a "syringe" type pump using a 304ss tube of 25mm ID, 3mm wall and the idea is to use a solid round ptfe piston.
For the actuator I intend to use a 2.2Nm stepper motor nema 23 closed loop with a 12mm OD 4mm step integrated ballscrew, 200mm stoke.
The head design is where the difficulty lies.
I want to build a head that is compatible with standart fittings big names metering pumps for hplc or flash tlc, but I do not know the fittings currently in use and thread standarts.
The head is to be the cap on the cylinder with check valves, using simple stainless steel ball and matching seat under spring load.
Maximum intended pressure 10 bar for use in available cartridges for flash chromatography.
According to ChatGPT the maximum pressure the 2.2 Nm stepper with ballscrew could achieve by pushing water through a 1.2mm orifice with 19mm ID tube is 1.29MPa or 12.9 bar.

Once the basic design is prototyped and troubleshooted a dual design will be attempted to achieve an even flow of liquid at set pressure.
Controls through some sort of microprocessor with display, arduino etc.


Thanks for your help!