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Toluene diamines (TDAs) in urine have been used widely to determine the amount of toluene diisocyanate (TDI) absorbed by humans. Conventional hydrolysis to prepare a sample of urine takes approximately 16 h. An attempt is made to apply microwave-assisted heating (MAH) to reduce the duration of analysis. Urine collected from rats exposed to a mixture of 2,4- and 2,6-TDI was diluted with non-exposed human urine 1/1250-, 1/500- and 1/250-fold. The urine samples were hydrolyzed by both conventional heating and MAH. The hydrolysis efficiency obtained using MAH significantly exceeded that obtained using conventional heating. Hydrolysis by MAH required only 20 min, 48 times faster than with conventional heating. The use of the MAH method in hydrolysis was demonstrated to be reproducible, timesaving and efficient technique in measuring the concentration of urinary TDAs.

Etude cinetique de la dissociation des complexes du cuivre (II) avec des composes aliphatiques de 10, 11 et 13 chainons

In order to investigate the effect of structure variation upon complex dissociation rate constants, the kinetics of the dissociation of (C·rac·5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane)copper(II) (red) cation has been examined spectrophotometrically at 25.0°C in 0.1–5.0 M HNO3. The cleavage of the second copper-nitrogen bond is proposed as the rate-determining step for this reaction. The possible pathways for the cleavages of the copper-nitrogen bonds, the factors influencing the dissociation rates, and the factors affecting the relative importance of each of these possible pathways are considered.

Sensitized photooxidation of isoeugenol gave 6 products. The elucidation of the structures of those products and the mechanism of their formation are discussed.