Determination of volatile substances in polystyrene foam food packaging by near infrared spectroscopy

Abstract

NIR spectroscopy was employed to determine volatile substances in polystyrene foam used for food packaging. The spectra of samples were scanned in the range 10000 to 4000 cm-1, 30 scans per spectrum at a resolution of 8 cm-1, using diffuse reflectance mode for measured samples. The raw spectra were preprocessed by multiplicative signal correction (MSC) and second derivative. Partial least squares regression (PLSR) was used to construct calibration model. Gas chromatography with flame ionization detector was used to determine actual concentration of volatile substances for constructing calibration model. The correlation coefficient (r) 0.9815, root mean square error of calibration (RMSEC) 26.2 mg/kg, bias -2.26, root mean square error of prediction (RMSEP) 26.7 mg/kg and residual predictive deviation (RPD) 5.7.