Abstract

The techniques of photoacoustic spectroscopy (PAS) and diffuse reflectance spectroscopy (DRS) are investigated for the quantification of silica using the IR bands at 1080, 797, 693, and 1875 cm⁻¹. It is observed that, in both techniques, signal intensity increases linearly with mass initially. However, signal saturation sets in at much lower masses (>2 mg) in PAS than in DRS (>30 mg), showing that saturation is strongly technique dependent, in addition to having dependence on the absorptivity of the sample. These findings are applied to the quantification of silica in laboratory-generated silica-kaolin mixtures. It is shown that, with the use of the weaker band at 1875 cm⁻¹ in DRS, satisfactory results for the quantification of silica are obtained.

Chemometrics applied quantitative analysis of iron oxide mixtures by terahertz spectroscopy

Ying Li, Tian-Yao Zhang, Zhao-Hui Zhang, Jian-Feng Yan, Xuan Zhao, Xiao-Yan Zhao, Xing-Yue Li, Xian-Hao Wu, Lu Yin, Yuan Yuan, and Jian-Mei Guo
Appl. Opt. 62(5) 1167-1174 (2023)

Photoacoustic spectroscopy with light scattering samples

R. Tilgner
Appl. Opt. 20(21) 3780-3786 (1981)

Analysis of isotopic CO₂ mixtures by laser photoacoustic spectroscopy

I. G. Calasso, V. Funtov, and M. W. Sigrist
Appl. Opt. 36(15) 3212-3216 (1997)

Off-resonant photoacoustic spectroscopy for analysis of multicomponent gas mixtures at high concentrations using broadband vibrational overtones of individual gas species

Ramya Selvaraj, Nilesh J. Vasa, and S. M. Shiva Nagendra
Appl. Opt. 58(15) 4118-4126 (2019)

Quantitative Fourier transform IR photoacoustic spectroscopy of condensed phases

Y. C. Teng and B. S. H. Royce
Appl. Opt. 21(1) 77-80 (1982)