latifims

HPLC_RT shift of the main peak

Discussion created by latifims on Apr 18, 2019
Latest reply on May 14, 2019 by wydnaa

I am using HPLC 1260 for sample analysis.

Mobile phase initially was:

MP A : 0.1 % H3PO4

MP B: CH3CN

Flow rate: 0.4 mL/min

Column Temp: 40 C

Column: Phenomenex LUNa Omega 3µm Polar C18 100 (150 X 3.0 mm)

My peak of interest shifts back and forth between consecutive injections. This also happened when I ran the blank sample (peaks associated with blank more around).

Based on suggestion I change the MP as follows:

MP A : 95% (0.1 % H3PO4) + 5% CH3CN

MP B: CH3CN

All other condition stayed constant.

I still have the isues.

The followings are 2 consecutive injections of same sample.

 

I have measured the delivery volume for A, B, and the combination. MP delivery is accurate.

 

Any thoughts and suggestions are appreciated.

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