Hello Jozef!
There is a special property within the LOINC database for your examination: MSCNC – Mass Substance Concentration. It allows for the combination of lab values of mass/volume or substance/volume units of measure. 35194-0 is for serum or plasma Bilirubin quantitative and 35193-2 is for body fluid Bilirubin.
If you simply enter MSCNC in RELMA search window, you’ll see the covered analytes in different body fluids. If a particular analyte is’t covered, you can submit to Regenstrief for a new term.
Hope this helps. Let me know what else can be answered.
Pam Banning