Stability of DAAN in water
An aqueous solution of DAAN (100 mg L1) was prepared using
water deaerated with 20-min argon bubbling and split into two
bottles. One bottle (oxic) was vigorously aerated under air, screw
capped and kept at room temperature in the dark. The second
one (anoxic) was capped with a rubber stopper, crimped with aluminum
seal, bubbled with argon for 10 min and incubated statically
at room temperature in the dark. Aliquots of the oxic and
anoxic solutions (3 mL) were periodically sampled and analyzed by HPLC–UV, UV–Vis, and LC–MS, as described below. The oxic
sample was stirred for 10 min under air at each sampling event.