“…A method for the determination of aromatic isocyanates in the presence of amines [340] is debatable. Chromophoric nature of the derivatizing agent is the prerequisite for the photometric determination of aliphatic diisocyanates after acidic hydrolysis; l-tluoro-2,4-dinitrobenzene has been found to be a suitable material [342][343][344][345]. Chromophoric nature of the derivatizing agent is the prerequisite for the photometric determination of aliphatic diisocyanates after acidic hydrolysis; l-tluoro-2,4-dinitrobenzene has been found to be a suitable material [342][343][344][345].…”