certified reference material, TraceCERT ® , 100 μg/mL in acetonitrile (as the aldehyde), ampule of 1 mL Synonym(s): Crotonaldehyde-2,4-DNPH solution; Crotonaldehyde-2,4-DNPH solution; Crotonaldehyde-2,4-dinitrophenylhydrazone solution RIDADR: UN 1648 3 / PGII