Page 1 of 1

Early eluted peak

Posted: Fri Sep 22, 2017 4:42 pm
by eaalzhrani
I'm using 1200 Agilent HPLC with Max-RP column (2.00 x 50) 4 (µm).

mobile phase is 5mM Ammonium formate in 10% methanol and 5mM Ammonium formate in 90% methanol.

My analyte retention time is 0.5 min with 0.5 mL/min flow rate.

the dead volume is 0.1 mL.

I want the peak to elute little bit later than 0.5 min.

I tried to reduce the flow rate to 0.25 ml/min but it showed a border peak.

I'm thinking to increase the buffer concentration in my mobile phase, what other solutions do you suggest that might help me to get a later RT.

Re: Early eluted peak

Posted: Sun Sep 24, 2017 10:04 pm
by tom jupille
No way to make reasonable suggestions without more details:
- what kind of analyte?
- is your separation isocratic or gradient (you mentioned two different mobile phases)
- if isocratic, what is the actual composition
- if a gradient, what are initial and final composition and ramp rate?