Chromatography Forum

Hi All

I'm in the process of doing some experiements to establish shelf life for our mobile phases (reverse phase). Has anybody done a similar project or any suggestions on how to do this?

Thankng you in advance
Mike Carolus

Fisrt define whether you are testing continued use of opened containers, or fresh constiners. Note also that shelf life data applies to specific methods, so choose those where the experiments will provide benefit. You need your quality people to sign off on the protocols before you start.

Simplest method is to make up a large amount of mobile phase, store in typical containers, and use them to analyse standards and/or samples alongside fresh mobile phase, preferably from the same batches of components that will not exceed manuafcture's expiry date during the trial ( apart from water ), in a time sequence relevant to how long you would normally use them. eg 1 day, 1 week, 2 weeks, 4 weeks, 3 months, 6 months, 1 year, etc.... You method quality data will tell you if results are acceptable.

Note that some components will have shelf lives determined by other factors, such as potential wildlife growth in biologically-benign fluids, eg pure aqueous, aqueous + buffers - typically 1 week maximum, unless you take extra precautions. Other time-limiting factors are moisture ingress ( hydroscropic solvents ) or stability ( ethers forming peroxides ), etc. etc. Don't waste time trying to entend those.

Organic components should last at least 6 months, if not to manufacter's expiry, and most mobile phases will have shelf lives somewhere in between pure aqueous and pure solvent.

Good luck,

Bruce Hamilton

We are generally doing this activity during the method validation. The mobile phase used for the analysis of first day analysis is, is again used to check the system suitability on different days, and a shelf life is assigned

Regards