Notes on verification

Confirmed by peer-reviewed study (Liang et al. 2018) stating ~1000 μg/g, corroborated by independent analytical chemistry study (Wei et al. 2009) finding 912±58 μg/g using capillary electrophoresis, and consistent with a third study reporting millimolar concentrations. Minor variation between studies expected due to natural variability and methodology differences. [tier=gold indep_score=1.0 clusters=3 claim_tier=notable | kind=empirical eligibility=high]