Fig. 2.

Multiple reaction monitoring (MRM) of GHB in a representative hair sample from a patient with SSADHD and a control. The transition from m/z 103 > 85 was monitored with ²H₆-GHB as internal standard. This obviated interference from other potential contaminants, including other butyric acid compounds, which also elute at different retention times than GHB (Wang et al. 2016). The GHB level in the patient’s hair sample was approximately 5.9-fold increased in comparison to control based upon peak area