Chromatography Forum

Hi guy, I am injecting a chloroform with a regular Hamilton needle. After 10 injections the needle is hard to move and eventually blocked. Any help will be appreciated. how about good way to cleaning it
P.S. I am cleaning it with hexane between the injections, so does the reaction between the chloroform and hexane causing this trouble ????, Also would cleaning with chloroform between the injections be better ??

Typically, we rinse the syringe with the same solvent as used to prepare samples and standards.

Your solution is causing the plunger to stick, not the chloroform itself.

Rinsing with chloroform, DCM or toluene, followed by methanol should fix your sticking problem.

Hexane and chloroform will not react under normal conditions.

What you have dissolved into the chloroform may react with the steel plunger, or may evaporate a sticky residue inside the barrel of the needle.

You have to determine the best path. That is why it is called research.

best wishes,

Rod