Figure 2

Mass spectrum of DS and HS in urine, as well as the internal standards of different MPS phenotypes and normal controls. (A) Normal control; (B) MPS I- Scheie; (C) mild form of MPS II; (D) severe form of MPS II; (E) MPS IIIB; and (F) MPS VI. *Same pairs of transition mass-to-charge ratio for [²H₆] CS and [²H₆] DS dimers (m/z 432 → 239), and the retention time (minutes) for [²H₆] CS and [²H₆] DS dimers is 3.71 ± 0.09 and 3.26 ± 0.05 minutes, respectively.