The ion mobility (IMS) spectra of the alkanolamines, monoethanolamine (MEA), 3-amino-1-propanol (PRA), 4-amino-1-butanol (BUA), and 5-amino-1-pentanol (PEA) with acetone and 4-heptanone reagent gases have been measured using a hand-held spectrometer. Monomer and dimer peak patterns were observed for all the alkanolamines with acetone reagent gas. Drift times of monomer and dimer ion clusters for each alkanolamine increased linearly in order of size of alkyl group. Ammonia, Freon 22, and F76 diesel vapors, having similar or coincident mobilities, caused severe interference. Replacement of acetone with 4-heptanone reagent gas resulted in good separation by the altering drift times of product ions. The limit of detection was 0.005 ppm having a linear range of 0.005-0.7 ppm, and signal saturation occurred above 0.88 ppm. Detection was reversible, with a response time of 4 min and a slower recovery time of > 60 min, at vapor levels of 0.7 ppm and ambient nozzle and drift-region temperatures. In contrast to acetone chemistry, single-peak patterns were observed for the alkanolamines with the 4-heptanone reagent. Further, drift times unexpectedly remained stagnant with increasing alkyl-group size. From atmospheric pressure chemical ionization (APcI) tandem mass spectral identifications and collision induced studies, dynamic changes in product-ion equilibria in the IMS drift region compensated by differences in collision cross sections were suggested as the governing causes of the unusual mobility effect.

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Shipboard and laboratory trials were conducted to determine airborne occupational exposure to isocyanates by brush/roller application of 2-pack polyurethane paints. Airborne concentrations in the breathing zones of the operators were found to be <0.1 lg/m 3 during the paint application to a vessel deck, in a tropical climate, in the open air. Similarly, brush/roller application of the paints in an enclosed space generated airborne isocyanate concentrations <3 lg/m 3 . The dust generated during light sanding of the polyurethane paint, 24 h after curing, did not show detectable levels of isocyanates.