What is the best choice of " flush solvent" in HPLC?

[alemaggot]

Hi guys,

As in the title... what is the best solvent and volume choice for flush the autosampler needle?

What you usually use?

Thank you!

Best regards

Ale

[skunked_once]

The best flush solvent has the following characteristics:

1-It will clean the sample matrix from the needle.
2-It will be compatible with your mobile phase.
3-It will not alter the separation of your method.
4-It will not interfere with whichever type of detector you are using.

There is no "best" flush solvent because everyone's case is different. You must determine which solvent will work best for you based on the above criteria.

"Choose wisely my son."

[lmh]

and it's worth taking the trouble to find out whether your autosampler merely washes the needle with this solvent, or whether it's also used in other ways, for example to fill the remainder of a sample loop when carrying out partial loop injections. This is particularly relevant when retention is marginal and the needle-wash/flush solution is a strong eluent.