Comparative Study of Linear Regression Models for the Infrared Reflection Spectroscopic Determination of Magnesium, Teflon, and Viton Pyrotechnic Compositions

The pyrotechnic composition of magnesium, Teflon, and Viton (MTV) is employed in solid rocket motor initiation systems, flares, and other applications. No studies addressing its quantification or evaluating statistical models have been reported in the consulted and available literature. Infrared spectroscopy enables the quantification of each component of a system in a fast and non-destructive manner. This study presents the application of the universal attenuated total reflection technique to the analysis of five laboratory-prepared samples with different MTV contents, in which the analytical bands of each component were used in calibration curves through different linear regression models. The test sample results demonstrate adequate agreement between the methodologies, with relative errors below 6.5% for the quantification of Viton and Teflon, with the estimation of Teflon being improved by the use of weighted linear regression. For magnesium, both the simple and weighted regression estimates fall outside the 95% confidence interval, indicating the presence of systematic error. The contribution to the state of the art lies in the evaluation of MTV (as-received samples) through infrared reflection techniques, using different statistical treatments, including those specifically designed for spectroscopic data.