Separation and characterisation of products of the reaction between propionamide and formaldehyde

Summary Propionamide-formaldehyde reaction products have been characterised using micellar electrokinetic chromatography (MEKC), HPLC-electrospray-MS (HPLC-ES-MS) and time-of-flight-MS (TOF-MS). HPLC-MS-MS was used to distinguish between isomeric species. The MEKC separation of all reaction products was obtained with good resolution and efficiency. Comparison of water-micelle distribution constants (P _MEKC) for propionamide-formaldehyde with those for caprolactam-formaldehyde reaction products suggests that the concentration of sodium dodecyl sulfate appropriate for use in MEKC is inversely related toP _MEKC. Quantification of all species containing one or two amide units was achieved using standard calibration, mass balance and the assumption of identical absorption coefficients for the same functional groups in monomers and dimers.