Recomendations for plasma deproteinization

[dragosb]

Hi,

I am trying to determine Tranexamic acid concentration in human plasma and I am using SSA (sulphosalicilic acid) to deproteinize the plasma sample. I still get a lot of unwanted peaks in the internal standard area on the chromatogram.
Please let me know if there are any other deproteinizing agents I can use for Heparinate dblood samples or if it is worth to change the concentration of SSA.

Thank you

[Alexandre]

Strong salt conc., TCA, strong % of ACN, MWCO devices and good centrifuging, or there are specialized cartridges if you can have a hand on them.