Tertiary amine catalysts used for manufacturing polyurethanes and polyisocyanurates are known to degrade over time, producing products such as aldehydes that can directly contribute to emissions of organic compounds. To remain within the tolerable exposure limits, an analytical method with sufficient accuracy is needed to ensure that no or low concentrations of aldehydes are present in the catalyst samples.
Recently, a systematic analytical approach was reported for the accurate determination of aldehydes present in amine catalysts or amines by liquid chromatography using ultraviolet (UV) detection of their 2,4-dinitrophenylhydrazone derivatives.1 Based on various factors controlling the derivatization of aldehydes, optimum conditions were selected for the accurate determination of aldehydes. In addition, probable reaction mechanisms in both acidic and basic conditions were highlighted.