Control of Standards in unstable equipment (LC-MS/MS)

[biotechno]

LC-MS/MS can be very unstable equipment in signal intensity between days, weeks, months.

Since the stability of standards and solvents can be very human dependent, expiration date alone can be tricky, since it doesnt control how many times:

. the working standard solution was already at room temperature;

. how much time was already left the standard solution open;

. and many other lab incidents we all know about..

In this situations, control charts became more important than expiration dates, but with the signal variation in LC-MS/MS equipment those can be completely irrelevant.

Does anyone have good ideas in how to overcome such difficulty?

Thank you all for your time.

[Peter Apps]

One thing that might help is to aliquot your standard into 1-day portions - then discard whatever is left over from the day's portion and open a new portion tomorrow.

Peter

[richiekichi]

It's a real pain in the bum. Anyway it's not the equipment you need to worry about, it's how the standards are stored.

http://www.eurl-pesticides.eu/userfiles ... Zipper.pdf