Fig. 3.

Comparison of SPE cartridges for the recovery of side-chain hydroxycholesterols after EADSA. RICs for (a) m/z 541.4493 ± 10 ppm showing [²H₇]24R/S-HC. Top panel SPE-2 is Waters Sep-Pak tC18 batch 011032331C; bottom panel SPE-2 is Waters Oasis HLB and (b) RIC for m/z 534.4054 ± 10 ppm showing endogenous side-chain hydroxycholesterols. Top panel SPE-2 is Waters Sep-Pak tC18 batch 011032331C; bottom panel SPE-2 is Waters Oasis HLB. Peaks in (a) and (b) are normalised to the most intense peak in each column