I am facing a carry-over issue in My ultivo attached 1260infinity series uplc how can i reduce the carry over.

How can i reduce carry over while injecting the sample prepared for making calibration Curve?

Even after priming the syringe before the analysis contains the previous carry over. 

this makes my accuracy values double than expected at lower concentrations of 5,10 and 20 nanograms.

thanks, and regards!

Milesh