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Simultaneous Visualization of Hydrogen Peroxide and Water Concentrations Using Photofragmentation Laser-Induced Fluorescence

Larsson, Kajsa LU ; Aldén, Marcus LU and Bood, Joakim LU (2017) In Applied Spectroscopy 71(9). p.2118-2127
Abstract

A concept based on photofragmentation laser-induced fluorescence (PFLIF) is for the first time demonstrated for simultaneous detection of hydrogen peroxide (H2O2) and water (H2O) vapor in various mixtures containing the two constituents in a bath of argon gas. A photolysis laser pulse at 248 nm dissociates H2O2 into OH fragments, whereupon a probe pulse, delayed 100 ns and tuned to an absorption line in the A2Σ+ (v = 1) ← X2Π(v = 0) band of OH near 282 nm, induces fluorescence. The total OH fluorescence reflects the H2O2 concentration, while its spectral shape is utilized to determine the H2O concentration via a model... (More)

A concept based on photofragmentation laser-induced fluorescence (PFLIF) is for the first time demonstrated for simultaneous detection of hydrogen peroxide (H2O2) and water (H2O) vapor in various mixtures containing the two constituents in a bath of argon gas. A photolysis laser pulse at 248 nm dissociates H2O2 into OH fragments, whereupon a probe pulse, delayed 100 ns and tuned to an absorption line in the A2Σ+ (v = 1) ← X2Π(v = 0) band of OH near 282 nm, induces fluorescence. The total OH fluorescence reflects the H2O2 concentration, while its spectral shape is utilized to determine the H2O concentration via a model predicting the ratio between the fluorescence intensities of the A2Σ+ (v = 1) → X2Π(v = 1) and the A2Σ+ (v = 0) → X2Π(v = 0) bands. The H2O detection scheme requires that the bath gas has a collisional cross-section with OH(A) that is significantly lower than that of H2O, which is the case for argon. Spectrally dispersed OH fluorescence spectra were recorded for five different H2O2/H2O/Ar mixtures; the H2O2 concentration in the range of 30–500 ppm and the H2O concentration in the range of 0–3%. Fluorescence intensity ratios predicted by the model for these mixtures agree very well with corresponding experimental data, which thus validates the model. The concept was also demonstrated for two-dimensional imaging, using two intensified charge-coupled device (CCD) cameras for signal detection. Water content was here sensed through the different temporal characteristics of the two fluorescence bands by triggering the two cameras so that one captures the total OH fluorescence while the other one captures only the early part, which mainly stems from A2Σ+ (v = 1) → X2Π(v = 1) fluorescence. Hence, the H2O2 concentration is reflected by the image of the camera recording the total OH fluorescence, whereas H2O concentration is extracted from the ratio between the two camera images. Quantification of the concentrations was carried out based on calibration measurements performed in known mixtures of H2O2 (30–500 ppm) and H2O (0–3%) in bulk argon. The detection limits for single-shot imaging are estimated to be 20 ppm for H2O2 and 0.05% for H2O. The authors believe that the concept provides a valuable asset in, for example, pharmaceutical or aseptic food packaging applications, where H2O2/H2O vapor is routinely used for sterilization.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
hydrogen peroxide, imaging, laser-induced fluorescence, Photofragmentation, water
in
Applied Spectroscopy
volume
71
issue
9
pages
10 pages
publisher
Society for Applied Spectroscopy
external identifiers
  • scopus:85028592369
  • wos:000408851300007
ISSN
0003-7028
DOI
10.1177/0003702817702386
language
English
LU publication?
yes
id
3ce73da3-892d-4d94-9160-5d310c18868d
date added to LUP
2017-09-26 11:48:47
date last changed
2018-09-23 08:35:22
@article{3ce73da3-892d-4d94-9160-5d310c18868d,
  abstract     = {<p>A concept based on photofragmentation laser-induced fluorescence (PFLIF) is for the first time demonstrated for simultaneous detection of hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) and water (H<sub>2</sub>O) vapor in various mixtures containing the two constituents in a bath of argon gas. A photolysis laser pulse at 248 nm dissociates H<sub>2</sub>O<sub>2</sub> into OH fragments, whereupon a probe pulse, delayed 100 ns and tuned to an absorption line in the A<sup>2</sup>Σ<sup>+</sup> (v = 1) ← X<sup>2</sup>Π(v = 0) band of OH near 282 nm, induces fluorescence. The total OH fluorescence reflects the H<sub>2</sub>O<sub>2</sub> concentration, while its spectral shape is utilized to determine the H<sub>2</sub>O concentration via a model predicting the ratio between the fluorescence intensities of the A<sup>2</sup>Σ<sup>+</sup> (v = 1) → X<sup>2</sup>Π(v = 1) and the A<sup>2</sup>Σ<sup>+</sup> (v = 0) → X<sup>2</sup>Π(v = 0) bands. The H<sub>2</sub>O detection scheme requires that the bath gas has a collisional cross-section with OH(A) that is significantly lower than that of H<sub>2</sub>O, which is the case for argon. Spectrally dispersed OH fluorescence spectra were recorded for five different H<sub>2</sub>O<sub>2</sub>/H<sub>2</sub>O/Ar mixtures; the H<sub>2</sub>O<sub>2</sub> concentration in the range of 30–500 ppm and the H<sub>2</sub>O concentration in the range of 0–3%. Fluorescence intensity ratios predicted by the model for these mixtures agree very well with corresponding experimental data, which thus validates the model. The concept was also demonstrated for two-dimensional imaging, using two intensified charge-coupled device (CCD) cameras for signal detection. Water content was here sensed through the different temporal characteristics of the two fluorescence bands by triggering the two cameras so that one captures the total OH fluorescence while the other one captures only the early part, which mainly stems from A<sup>2</sup>Σ<sup>+</sup> (v = 1) → X<sup>2</sup>Π(v = 1) fluorescence. Hence, the H<sub>2</sub>O<sub>2</sub> concentration is reflected by the image of the camera recording the total OH fluorescence, whereas H<sub>2</sub>O concentration is extracted from the ratio between the two camera images. Quantification of the concentrations was carried out based on calibration measurements performed in known mixtures of H<sub>2</sub>O<sub>2</sub> (30–500 ppm) and H<sub>2</sub>O (0–3%) in bulk argon. The detection limits for single-shot imaging are estimated to be 20 ppm for H<sub>2</sub>O<sub>2</sub> and 0.05% for H<sub>2</sub>O. The authors believe that the concept provides a valuable asset in, for example, pharmaceutical or aseptic food packaging applications, where H<sub>2</sub>O<sub>2</sub>/H<sub>2</sub>O vapor is routinely used for sterilization.</p>},
  author       = {Larsson, Kajsa and Aldén, Marcus and Bood, Joakim},
  issn         = {0003-7028},
  keyword      = {hydrogen peroxide,imaging,laser-induced fluorescence,Photofragmentation,water},
  language     = {eng},
  month        = {09},
  number       = {9},
  pages        = {2118--2127},
  publisher    = {Society for Applied Spectroscopy},
  series       = {Applied Spectroscopy},
  title        = {Simultaneous Visualization of Hydrogen Peroxide and Water Concentrations Using Photofragmentation Laser-Induced Fluorescence},
  url          = {http://dx.doi.org/10.1177/0003702817702386},
  volume       = {71},
  year         = {2017},
}