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A technique based upon transmission FTlR to obtain rate constants for adsorption and desorption over supported metal catalysts has been developed and tested. The technique requires the use of a sinusoidal perturbation function imposed on steady state linearized adsorptiondesorption kinetics. The measurement of a phase lag between the sinusoidal inlet gas phase forcing concentration and the response of surface coverage, together with a measurement of the maximum amplitudes of the forcing function and surface response enable the calculation of the relevant adsorption and desorption rate constants.The technique has been successfully applied to the measurement of both adsorption and desorption rate constants for CO adsorbed on a 1% Pt/SiO, catalyst. The values obtained for these rate constants at 343 K were: Ka = 0.147 s-' and K,, = 7.28 x s-'. A sticking coeftlcient corresponding to the adsorption of weakly bonded CO on Pt under conditions of high CO surface coverage was obtained.

Solvent exchange by distillation is a common unit operation in active pharmaceutical ingredient (API) manufacturing processes. Either a stepwise solvent displacement mode or a constant volume solvent displacement mode can be used to carry out the solvent exchange. The constant volume mode can be more efficient as the chasing solvent acts as an effective displacer by keeping concentrations of the solvent being displaced at higher levels. As demonstrated during a production application at Abbott Laboratories, the constant volume solvent displacement mode resulted in a 30% reduction in the quantity of displacing solvent, 2-propanol (IPA), when compared with the equivalent process using a stepwise solvent displacement mode. As a consequence, 30% reduction in the waste solvent generation was realized. This mode of operation dose not adversely impact product quality nor process yield.

The incorporation of two fluorine-containing general anesthetic agents, halothane and methoxyflurane, into erythrocytes (from three different species), rabbit muscle and rabbit nerve, was followed with 19F NMR spectroscopy. Two major findings emerged from these studies: (1) multiple environments indicative of domain structure in the membrane can be observed depending on the anesthetic and the tissue type; and (2)

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