in diluent injection iam observing many peaks

[dood4v]

hi dear all,
we have used 0.1% TFA and 1mm of HFBA in water as mobile phase-A, & acetonitirle as mobile phase-B
the diluent was water and the coloumn was phenomenex c-18,4.6x25cm coloumn.
In diluent i am observing many small peaks and also the peak exactly at the Rt of the product peak.

i dont know the reason.can anyone can suggest the reason.

[DR]

wavelength of detector (assuming detection is UV...)?

If it is a low wavelength (~254 or lower), it might be a good idea to search these forums for methods of testing and cleaning up your water. Good terms to use might be "Empore extraction" or ""gradient artifact" or "gradient system peaks".

[tom jupille]

That's a common enough problem that we actually have a brief tutorial on it:
viewtopic.php?f=31&t=19085