1985 Volume 34 Issue 1 Pages 11-15
Determination of trace water in organic solvents was investigated by high performance liquid chromatography as its di(α-naphthyl)urea derivative. A sample solvent (1 ml) was injected to a screw-capped vial through a silicone rubber septum. α-Naphthyl isocyanate (30μl) and triethylamine (30 μl) were added, and the mixture was heated to 100 °C for 90 min. Pentanol (50 μl) was then added and the heating was continued for further 30 min. All the procedures were carried out in a drying box protected from moisture. By this treatment water in the sample was converted to di(α-naphthyl)urea, and the excess reagent was transformed to pentanol α-naphthylurethane. Dimethylformamide (1 ml) was added to the mixture to give a homogeneous solution, which was then analyzed on a reversed phase column with THF/water (60/40) as mobile phase. Dimethyl phthalate was used as internal standard. The chromatograms were monitored at 280 nm. The calibration cuve was linear from 2 to 250 ppm water in carbon tetrachloride. The reproducibility of determination was 4.5 % at five runs. Similar results were obtained in the determination of water in benzene.
