Methyl 4-hydroxybenzoate-2,3,5,6-d4,neat,neat,50mg,

12.880 µS/cm conductivity solution (230mL)

2,3,4,5-Tetrabromobenzoic acid [13C6 ring], 1.2ml x 50ug/ml, methanol

(±)-Vanillomandelic acid-d3,neat,neat,50mg,