Photothermal techniques: a useful tool to analyze edible oils pureness

Abstract

Photothermal techniques are based on the thermal waves detection, such waves are generated when a modulated light strikes on a sample material, thermal waves then travel through the material, is the material is homogenous then thermal waves propagate freely and, only suffering an attenuation as a function of traveled distance, when the material has defects the waves will suffer not only attenuation but also a dispersion process. The attenuation and dispersion processes are related to the light modulation frequency, sample homogeneity, the sample optical properties and sample thermal properties. Therefore, the thermal waves carry information about thermal and optical properties of the material and its internal structure.