Chromatography Forum

Dear Friends,

Can someone pls inform what happens to the substance other than the residual solvents when the active pharma ingrediant is injected (after dissolving in solvent).

since the entire molecule is fragmented, how is the residual solvents alone picked up without interference.

request someones help.

thanks

Hi David,

The best way to control residual solvents in API is with a Head Space system of injection in a GC.

You will only inject the vapor phase and then the molecule will not be injected in the system.

Any problem consult with European Pharma ...

The drug matrix will generally not be volatile and remains in the injector port liner 'dried' and cooked at the inlet temperature. It may decompose into various products which may or may not foul the column and give active sites in the injector. Many users prefer to use packed columns to perform residual solvent testing with non-volatile matrices as they are cheaper to replace and last longer in many cases that FSOT capillary columns.

In short the 'drug' doesn't go anywhere, it stays in the injector port.