Shimadzu 2010 retention time moving..

[rams]

while doing shimadzu 2010 auto injector calibration iam getting different retention times and areas for 200 micro litre injection.we are having 500 micro litre loop..could you solve.....

[unmgvar]

first check the pump actually
if the flow is not stable it will give you not only retention time drifts but also area drifts
as the peak retains more the area increases, slower flow higher area

[tom jupille]

Check the dead time (t0).

If dead time and retention time (tR) change by the same percentage, then you have a flow problem.

If they both change by the same absolute amount, then there is an issue with the the start signal timing (perhaps the autosampler cycle time?).

If the dead time stays constant and retention time changes, then you have a chemistry or temperature problem.

[rahul pant]

Hi!
Please check if the rotor seal has been replaced when you have installed the 500 ul loop.There is different HPV rotor seal(with bigger grooves).
If this has not been replaced and the old one(with small groove) being used, you have no problems upto 100 ul injection.But when you increase the volumemore, then the area and RT variation occure!

Cheers!
Rahul