Quantitative Analysis of Sodium Carbonate and Sodium Bicarbonate in Solid Mixtures Using Fourier Transform Infrared Spectroscopy (FT-IR)

An analytical methodology is proposed based on constant ratio and absorbance correction methods to quantify sodium carbonate, Na2CO3 (1450 cm(-1)), and sodium bicarbonate, NaHCO3 (1000 cm(-1), 1923 cm(-1)), in solid mixtures using Fourier transform infrared (FT-IR) spectroscopy. Potassium ferricyanide, K3Fe(CN)(6) (2117cm(-1)), was used as an internal standard to get characteristic parameters. NaHCO3 was quantified using the constant ratio method. Spectral interference of NaHCO3 in Na2CO3 (1450 cm(-1)) was corrected using the absorbance correction method. The corrected absorbance was successfully applied to quantify Na2CO3 (1450 cm(-1)) in the mixture using the constant ratio method. The results obtained for simulated samples were satisfactory (relative standard deviation less than 7%) for all samples.