Table 1.

LC-MS parameters use for detection of sterol metabolites

Sterol	MRMa	RT (min)	LOQ (ng/mL)	LOD (ng/mL)	CE (V)	Q1 pre bias (V)	Q3 pre bias (V)
24,25-dihydrolanosterol	411.30 > 191.10	14.5	5.60	1.90	−17	−11	−15
FF-MAS	393.30 > 309.20	12.5	4.68	1.56	−23	−19	−17
T-MAS	395.00 > 243.00	12.8	9.34	3.13	−18	−20	−19
Zymosterol	367.30 > 215.10	11.0	6.29	2.08	−20	−13	−26
Lathosterol	369.30 > 215.10	12.3	10.1	3.32	−22	−13	−17
24-dehydrolathosterol	367.30 > 215.10	11.4	4.44	1.47	−20	−13	−26
Desmosterol	367.30 > 215.10	11.7	12.9	4.27	−20	−13	−26
Lanosterol	409.30 > 191.10	13.1	4.37	1.44	−14	−11	−15
Zymostenol	369.30 > 215.10	12.0	5.37	1.77	−22	−13	−17
7-dehydrodesmosterol	365.30 > 199.10	11.4	4.05	1.34	−18	−13	−16
Dehydro-T-MAS	397.40 > 177.10	14.4	8.09	2.67	−19	−11	−21
Dehydro-FF-MAS	395.50 > 123.10	13.8	6.30	2.08	−25	−11	−24
Lathosterol-D7	376.30 > 215.10	12.4	/	/	−22	−13	−17
Cholesterol	369.30 > 215.10	12.8	2000b	/	−22	−13	−17
24,25-epoxylanosterol	425.15 > 95.20	9.0	6.55	2.18	−30	−22	−11

MRM, Multiple Reaction Monitoring; RT, Retention Time; LOQ, Limit of Quantification; LOD, Limit of Detection.

^aFor MRM measurements of deuterium labeled sterols (D6), Q1 mass +6 was used, Q3 mass remained the same as in natural sterols).

^bLOD/LOQ for cholesterol was not tested lower as concentrations in samples are higher.