Taurodeoxycholic acid is a bile acid. This compound is a closely related isomer of taurochenodeoxycholic acid and tauroursodeoxycholic acid sharing the exact molecular formula and molecular weight.
Taurodeoxycholic acid and its isomers have molecular masses similar to perfluorooctanesulfonic acid (PFOS) and therefore may interfere with interpretation of mass spectrometry data, leading to a false indication of the presence of PFOS in a biological sample.[1]