Analysis of the HDO content in heavy water by ATR-FTIR

The applicability of ATR-FTIR for the determination of the HDO content in heavy water (D₂O) was investigated. Two groups of calibration standard solutions, of low contents (0–1 n% H₂O in heavy water) and of higher contents (0–10 n% H₂O in heavy water) were prepared by adding properly calculated amount of H₂O to D₂O by weight. The absorbances at 3400 cm⁻¹ (ν, O–H) against the calibration standards were measured five times using two kinds of interchangeable IREs (1 bound and 9 bound reflections). And four calibration curves were obtained by linear least square fit of the measured absorbances for the four different measurement conditions, which are (1) for low contents group using 1 bound reflection, (2) for low contents group using 9 bound reflections, (3) for higher contents group using 1 bound reflection, (4) for higher contents group using 9 bound reflections. Determined contents (c ₀) of each calibration standards for the four measurement conditions were obtained by the calibration curves and compared to the calculated contents (c _cal). The uncertainty sources were considered when the HDO in heavy water is determined according to the procedure of this work. The uncertainties u(c ₀) of the determined contents (c ₀) for the four different measurement conditions were calculated.