Recrystallise adrenor from EtOH and store it in the dark under N2. [pKa, Lewis Brit J Pharmacol Chemother 9 488 1954, UV: Bergstr.m et al. Acta Physiol Scand 20 101 1950, Fluorescence: Bowman et al. Science NY 122 32 1955, Tullar J Am Chem Soc 70 2067 1948.] The L-tartrate salt monohydrate has m 102-104.5o, [] D -11o (c 1.6, H2O), after recrystallisation from H2O or EtOH. [Beilstein 13 III 2382.]