Determination of total organic carbon on hybrid organic-inorganic mesoporous silica by FT-NIR spectroscopy

Abstract

The potential of Fourier transform near-infrared reflectance spectroscopy (FT-NIRS) to predict the organic loading on hybrid organic–inorganic mesoporous silica was studied. Fourty nine samples of MCM-41 functionalized silica were used to build and cross-calibrate a partial least squares (PLS) model, based on the comparison between NIR spectra and thermoanalytical total organic carbon (TOC) measurement. The model was externally calibrated with fifteen reference samples and the error of prediction was determined. The method was robust and stable for samples characterized by a similarity in the organic functional group. FT-NIRS represents a valid, non-destructive analytical technique employable in the synthesis of hybrid silica samples as an alternative to classical thermoanalytical methods for measurement of organic loading.