HPLC ISSUE

Hi,

1. Measure flow before column and then from drain line by using digital liquid flow meter or any measuring glass vial with stop watch.Then see flow is okay or not.

2.

Check out valve of pump may malfunctioning so try to change it.

3.

Variation of temperature of column compartment will vary RT.

4.

Replaced column is same as previous or not.

If all above is okay then do calibration again to see the result.

Thanks

Hi,

1. Measure flow before column and then from drain line by using digital liquid flow meter or any measuring glass vial with stop watch.Then see flow is okay or not.

2.

Check out valve of pump may malfunctioning so try to change it.

3.

Variation of temperature of column compartment will vary RT.

4.

Replaced column is same as previous or not.

If all above is okay then do calibration again to see the result.

Thanks

I already did all those steps. Other idea

So, you checked the flow and it's okay.

If flow at outlet of dain line is okay and constant then complete system flow is okay..

How much is flow.

Make sure, mobile phase is not contaminated..

If we assume that system is ok( generally propotional valve/ check valve/ no bubble in line/sample loop is not over loaded/ no leak/constant flow/ no pressure variation) then this problem may link with some chemical related.

I will suggest use new mobile phase and condition this new column with new mobile phase at least 10 to 12 hour.After that run sample to see repeatability n RT..