Can you help me engineer this leak detection system for organic solvents?

I have a machine that supplies solvent via argon pressure. What I would like to do is install a leak detection system that would halt the argon, solvent (acetonitrile), and power to the unit if tripped. At the moment, I’m envisioning putting the unit in a tray, with the leak detector in the bottom. If it sees fluid, a NC solenoid will de-energize inline with the argon and solvent supplies, and open the power circuit.

What I’d like is assistance finding the best leak detector and maybe any other suggestions for the project design. I’ve got a leak detector on another somewhat similar machine and was going to start with that, but as this is in the very beginning phase of the project, any engineering assistance from someone with relevant experience might help.