TY - JOUR
T1 - Photoacoustic technique in the transmission configuration for quantitative analysis of liquids
AU - Balderas-López, J. A.
AU - Díaz-Reyes, J.
PY - 2011
Y1 - 2011
N2 - A photoacoustic methodology for the measurement of optical absorption coefficient for pigments in liquid solution is introduced. The mathematical model, involving the Beer-Lambert model for light absorption, is a generalization of a previously reported photoacoustic methodology, involving a surface absorption model, used for thermal diffusivity measurements of liquids. The optical absorption coefficient for aqueous solutions of copper sulfate and methylene blue at various concentrations where measured at a wave-length of 658 nm, to show the range of optical absorption coefficients where the Beer-Lambert model for light absorption applies. It was experimentally shown that at high pigment's concentrations the surface absorption limit is more adequate and, consequently, the sample's thermal diffusivity is obtained instead of the optical absorption coefficient. Optical and thermal properties obtained by means of this photoacoustic methodology resulted in close agreement with the corresponding ones obtained by means of conventional optical spectroscopy and the previously reported photoacoustic methodology for thermal diffusivity measurements, respectively. Results show that this technique has promise applications in the field of quantitative analysis.
AB - A photoacoustic methodology for the measurement of optical absorption coefficient for pigments in liquid solution is introduced. The mathematical model, involving the Beer-Lambert model for light absorption, is a generalization of a previously reported photoacoustic methodology, involving a surface absorption model, used for thermal diffusivity measurements of liquids. The optical absorption coefficient for aqueous solutions of copper sulfate and methylene blue at various concentrations where measured at a wave-length of 658 nm, to show the range of optical absorption coefficients where the Beer-Lambert model for light absorption applies. It was experimentally shown that at high pigment's concentrations the surface absorption limit is more adequate and, consequently, the sample's thermal diffusivity is obtained instead of the optical absorption coefficient. Optical and thermal properties obtained by means of this photoacoustic methodology resulted in close agreement with the corresponding ones obtained by means of conventional optical spectroscopy and the previously reported photoacoustic methodology for thermal diffusivity measurements, respectively. Results show that this technique has promise applications in the field of quantitative analysis.
KW - Absorption
KW - Diffusivity
KW - Optical
KW - Photoacoustic
KW - Thermal
UR - http://www.scopus.com/inward/record.url?scp=84857694614&partnerID=8YFLogxK
M3 - Artículo
SN - 0035-001X
VL - 57
SP - 452
EP - 459
JO - Revista Mexicana de Fisica
JF - Revista Mexicana de Fisica
IS - 5
ER -