HPLC chromotogram errors

[feride]

Hello dear colleagues.I have problem with my Agilent HPLC 1290 and i hope you will help me.I have new prepared calibration standards and good calibration curve.When i analyze any sample with this calibrated method the retention time have replaced. We use same solvent, same ambient conditions and chromatographic water for standards and sample preparation. And the result of our testing I can not see the amount of compounds. It relate with the replacing of retention time. I built the calibration curve and sample analyse in same day. What I have to do?

[Gerhard Kratz]

Maybe it is a matrix problem, a problem with all the other compounds in your sample. I would try to prepare standards together with the matrix to see if the standard chromatograms will also change.
Good luck.

[kubowicz.tomasz]

Hello

1.Sample and injection solvent can affect retention time - try to dissolve sample in mobile phase and see if problem exists.
2.How big is retention time drift? sometimes when you have overloaded peak (API) you can see slightly difference for other peaks.
3.Check your calibration setting - you have tolerance range to automatically identify your peak based on retention time. Perhaps is less than 5%.

Regards

Tomasz Kubowicz