A rapid infrared method for the quantitative analysis of relative amounts of D2O and H2O in mixtures as they are obtained in quantities as small as 0.01 ml from reaction mechanism studies off a gas chromatographic column was developed in our laboratory. Several methods have been described in the literature (1-3). Some in the near infrared region (4) are either time-consuming or require special additional equipment (5). The method to be described has the advantage of being independent of the sample concentration in the solvent since it is based on the absorbance ratios of the OH and OD stretching bands at 2.83 and 3.90 microns. The total water content is not measured although a high degree of accuracy on the relative concentrations of the two components is attainable.
Helga S. Fochler, "A Rapid Infrared Method for the Quantitative Determination of D2O-H2O Mixtures," Appl. Spectrosc. 17, 105-106 (1963)