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RESEARCH PRODUCT
Determination of carbonates in waters by on-line vapor generation FTIR
Salvador GarriguesAmparo Pérez-ponceM. De La Guardiasubject
Detection limitAqueous solutionChemistryInfraredAnalytical chemistryAbsorbancechemistry.chemical_compoundsymbols.namesakeFourier transformNitric acidCalibrationsymbolsFourier transform infrared spectroscopySpectroscopydescription
Abstract An electrically heated gas-permeation unit (GPU) has been employed for the vapor-generation Fourier transform infrared (FTIR) determination of total carbonate in waters. The developed method is based on the simultaneous injection of 100 μ l sample and 100 μ l nitric acid in a two-channel manifold with a merging zone, which provides the generation of CO 2 through the GPU, heated at 90°C, from which CO 2 is swept by a stream of N 2 to a long-path infrared gas cell. Absorbance measurements were made in the range from 2500 to 2150 cm −1 and the corresponding flow injection recordings were obtained as a function of time. The areas of these peaks are interpolated in a calibration equation obtained from aqueous standards of Na 2 CO 3 treated in the same way as samples. The method provides a limit of detection of 4.6 ppm (expressed as mg of HCO 3 − l −1 ) and a sampling frequency of 30 h −1 . Results obtained for a series of natural waters compare well with those obtained by a titrimetric reference method.
year | journal | country | edition | language |
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1998-03-01 | Vibrational Spectroscopy |