Open photoacoustic cell spectroscopy

Abstract

The possibility of using a minimal-volume photoacoustic cell to perform spectroscopy of samples is discussed. It is shown that this alternative signal-to-noise-enhanced photoacoustic configuration allows one to obtain both absorption and transmission spectra with minimal experimental arrangement and cell machining requirements. The theoretical model is presented, the use of which is exemplified by a complete optical and thermal characterization of leaves.

Photoacoustic procedure for measuring thermal parameters of transparent solids

“…A possible way of distinguishing among these effects is the use of photoacoustic techniques ͑PA͒, in particular by investigating the PA dependence on the modulated chopping frequency of the incident light beam f. These techniques are versatile, nondestructive, and can be employed under different experimental conditions for determining thermal parameters of solid materials. Several photoacoustic cells with slight modifications, [5][6][7][8] including the derivative photopyroelectric 8,9 and photothermal deflection 10 methods, have been used in some special cases with great success. [11][12][13] The apparatus for all techniques is basically the same, the modifications being mainly concentrated on the type of detector and on its location relative to the sample inside the cell.…”

Photoacoustic Technique Applied to Skin Research: Characterization of Tissue, Topically Applied Products and Transdermal Drug Delivery

“…The double faced PA cell employed, with an electret microphone, was developed at UNIVAP; sensitivity was 15 mV/Pa for the frequency employed in skin measurements, www.intechopen.com 17Hz. The electret microphone structure was described by Marquezini et al (1990). The PA cell has a cylindrical body and two opposite, parallel faces (one is closed by a thin glass layer and the other, by the sample itself).…”

In situphotoacoustic spectroscopy of phycobiliproteins inGracilaria chilensis

“…The quantification of the extracted amount of phycobiliproteins was calculated from absorbance data [8]. In situ PA absorption spectra of the alga and PA transmittance for PBS and phycobiliproteins spectra were also recorded [5]. PA spectrum analyzed on Gaussian components: Spectral fitting by Gaussian Peak Deconvolution (bottom).…”

“…The optical absorption maxima for these phycobiliproteins are 566 nm for R-PE, 621 nm for C-PC and 651 nm for APC [1,2]. The photoacoustic spectroscopy (PAS) technique has been used in a variety of materials [3][4][5][6][7]. In this work photoacoustic spectroscopy (PAS) was applied to investigate the phycobiliproteins expression in an eukaryotic red algae: Gracilaria chilensis.…”