Determination of bisphenol A (BPA) by gas chromatography-mass spectrometry and 1H NMR spectroscopy during curing of epoxy-amine resins

Two analytical methods were developed to characterize the fate of bisphenol A (BPA) added in low amounts (1-4 wt%) in two different epoxy-amine-BPA systems, one based on a mixture of aliphatic amine curing agents, diethylene triamine (DETA) and poly(oxypropylene)diamine (Jeffamine) and the other on the less reactive diaminodiphenylsulphone (DDS) hardener. The method involves a liquid-liquid extraction (LLE) procedure up to gelation. Identification and quantification was performed by gas chromatography-mass spectrometry (GC-MS) and proton nuclear magnetic resonance (1H-NMR) spectroscopy. The data obtained by the two methods are in agreement. The main purpose of this study was to determine the extent of aryl-etherification in actual complex epoxy/amine formulations. It serves notably to detect potential contamination of the atmosphere, water, and soil in the area surrounding where the unbound BPA is released.