Table 2.
Electrospray ionization-tandem mass spectrometry operating parameters for bile acid intermediates
| Glycine conjugates (IS included) | Taurine conjugates | Sulfatides | Glucuronides | |
| Nebulizer gas (au) | 11 | 11 | 11 | 11 |
| Curtain gas (au) | 9 | 9 | 9 | 9 |
| Collision gas (au) | 5 | 5 | 5 | 5 |
| Ion spray voltage (V) | -4100 | -4100 | -4100 | -4100 |
| Temperature (°C) | 200 | 200 | 200 | 200 |
| Declustering potential (V) | -35 | -35 | -35 | -35 |
| Focusing potential (V) | -31 | -31 | -31 | -31 |
| Entrance potential (V) | -10 | -10 | -10 | -10 |
| Prefilter (V) | 23 | 23 | 23 | 23 |
| Collision energy (V) | -55 | -129 | -60 | -75 |
| Collision cell exit potential (V) | -9 | -9 | -9 | -9 |
| Daughter ion (m/z) | 74 | 80 | 97 | 85 |
| Scan range of precursor ions (m/z) | 430 to 550 | 490 to 590 | 460 to 490 | 600 to 630 |
The mass spectrometer was operated in a negative precursor ion scan mode with a step-size of 0.1 amu. Nitrogen was used as nebulizer, curtain and collision gases. au: Arbitrary units; IS: D4-glycocholic acid.