An alternative method to measure carbonate in soils by FT-IR spectroscopy

New York

Springer

2007

9-12

Sonderdruck

204947

Environmental chemistry letters ; Jrg. 5 ; 1 (2007) , 9-12

Measurements of calcium carbonate contents in soils were performed with FT-IR (Fourier transform infrared) spectroscopy and with the gas volumetric Scheibler method. To the authors’ knowledge it is the first time that carbonate was quantified in soil samples by FT-IR spectroscopy. The carbonate contents of the test soils ranged from 11.3 to 13.1%. Both methods gave similar results, however, results obtained from FT-IR spectra depend on the spectral band used for the carbonate determination. In our investigation we used the bands at 875 and 2506 cm−1. In case of the band at 2506 cm−1 the difference between FT-IR and Scheibler method was a factor of 1.56, in case of 875 cm−1 the respective factor was 1.16. It can be concluded that FT-IR with both bands has a potential to be used in practice as substitution of the Scheibler method. The advantages of the FT-IR method are better reproducibility and the simultaneous characterization of soil organic matter in bulk samples. The disadvantage is its higher cost.
Keywords: Carbonate FT-IR spectroscopy KBr method Soils