Table 1: Fragmentation patterns of the bile acid TMS (oximes) derivatives obtained using gas chromatography and mass spectrometry (GC/MS) and the common ions in the fragmentation patterns of cholic acid (conventional and microwave-assisted derivatization) and ursodesoxycholic acid (MAD) presented as relative intensities.

Bile acid (min) Selected fragment ions for identification and quantificationFrequent ion in fragmentation

Further abundant fragment ion, m/z m/z Relative intensity (%) microwaveRelative intensity (%) conventional

Cholic 17.19 696.5 681[M − 2TMSOH]+ = 516253100100
[M − (2TMSOH + SiCH4)]+ = 42842647.9456.74
[M − 3TMSOH]+ = 42651632.2339.61
68115.7614.87

Ursodesoxycholic 17.59 608.5 593[M − 2TMSOH]+ = 42841332
[M − (15 + 2TMSOH)]+ = 41342856
518100