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Non-Destructive Method for Alkaline Reserve Determination in Paper. Diffuse Reflectance Infrared Fourier Transform Spectroscopy

2004; De Gruyter; Volume: 25; Issue: 1 Linguagem: Inglês

10.1515/rest.2004.47

1865-8431

Josep Ma Gibert Vives, Josep Ma Dagà Monmany, Rogelio Areal Guerra,

Material Properties and Processing

Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) was applied to the quantitative analysis of magnesium carbonate content in papers treated with non-aqueous deacidifying solution. The method proved to be reasonably accurate for papers which are susceptible to impregnation, so that carbonate deposits are evenly distributed throughout the paper (or its surface, where the actual measurement takes place). The curve-fitting was performed by classical leastsquares technique, using several sets of spectra from papers loaded with 0 to 7% (w/w) MgCO3. The method is applicable to low surface sized papers, the spectra of which are not very different from that of pure cellulose. Compared with the standard method for measuring alkaline reserve, based on acid-base titrimetry, DRIFT spectrometry provides a non-destructive, fast, clean method capable of giving a lot of information about the reserve distribution on the treated materials; so it can complement the current deacidification quality control methods (surface and water extract pH, DPv, mechanical tests, SEM-EDX, ICP, etc.).