Fig. 13.2.

Detection of CYP11A1-derived 7DHC and D3 hdroxyderivatives in the human epidermis and serum

LC-MS spectra were measured on fractions with retention times corresponding to either 22(OH)7DHC or 20,22(OH)₂7DHC or 20(OH)D3, 22(OH)D3, or 25(OH)D3 that were pre-purified on a Waters C18 column (250 × 4.6 mm, 5 μm particle size) with a gradient of acetonitrile in water as described in [202]. Arrows indicate the retention times of the corresponding standards. Inserts show the mass spectra corresponding to the retention time of detected compound. In the outer panel, extracted ion chromatograms are shown for human epidermis (a and d), serum (b and e), and the pig adrenal (c and f). The work is reprinted from [202] under the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/) with small modifications