Detection of Hydrogen Peroxide Using Photofragmentation Laser-Induced Fluorescence

2008 ◽  
Vol 62 (1) ◽  
pp. 66-72 ◽  
Author(s):  
O. Johansson ◽  
J. Bood ◽  
M. Aldén ◽  
U. Lindblad
Keyword(s):  
Hydrogen Peroxide ◽  
Detection Limit ◽  
Signal Strength ◽  
Measurement Procedure ◽  
Laser Induced Fluorescence ◽  
Excitation Pulse ◽  
Oh Radicals ◽  
Single Shot ◽  
First Time ◽  
Hydrogen Peroxide Vapor

Photofragmentation laser-induced fluorescence (PF-LIF) is for the first time demonstrated to be a practical diagnostic tool for detection of hydrogen peroxide. Point measurements as well as two-dimensional (2D) measurements in free-flows, with nitrogen as bath gas, are reported. The present application of the PF-LIF technique involves one laser, emitting radiation of 266 nm wavelength, to dissociate hydrogen peroxide molecules into OH radicals, and another laser, emitting at 282.25 nm, to electronically excite OH, whose laser-induced fluorescence is detected. The measurement procedure is explained in detail and a suitable time separation between photolysis and excitation pulse is proposed to be on the order of a few hundred nanoseconds. With a separation time in that regime, recorded OH excitation scans were found to be thermal and the signal was close to maximum. The PF-LIF signal strength was shown to follow the same trend as the vapor pressure corresponding to the hydrogen peroxide liquid concentration. Thus, the PF-LIF signal appeared to increase linearly with hydrogen peroxide vapor-phase concentration. For 2D single shot measurements, a conservatively estimated value of the detection limit is 30 ppm. Experiments verified that for averaged point measurements the detection limit was well below 30 ppm.

Simultaneous Two-Dimensional Visualization of Soot and OH in Flames Using Laser-Induced Fluorescence

1996 ◽  
Vol 50 (9) ◽  
pp. 1182-1186 ◽  
Author(s):  
Per-Erik Bengtsson
Keyword(s):  
Laser Radiation ◽  
Detection System ◽  
Frequency Doubling ◽  
Ccd Camera ◽  
Laser Induced Fluorescence ◽  
Oh Radicals ◽  
Single Shot ◽  
Two Dimensional ◽  
Charge Coupled Device ◽  
Reaction Zones

Two-dimensional visualization of soot has been realized in flames with the use of laser-induced fluorescence in C2 from laser-vaporized soot [LIF(C2)LVS]. Soot particles are heated to vaporization temperatures by the absorption of laser radiation. C2 radicals produced by this process are excited at wavelengths around 563 nm through the transition v’ = 0 d3Πg ← v” = 1 a3Πu, and the subsequent fluorescence at ∼516 nm is detected. By frequency-doubling of the laser radiation, wavelengths around 281.5 nm are achieved, which can excite OH radicals to the v’ = 1 A2∑+ state from v” = 0 X2Π, with subsequent fluorescence at ∼310 nm. With the use of both these excitation wavelengths, and a Cassegrainian split-mirror telescope as the imaging detection system in front of the charge-coupled device (CCD) camera, simultaneous two-dimensional single-shot images of soot and OH were obtained on a single CCD chip, thus enabling both sooting regions and reaction zones in flames to be monitored.

scholarly journals Laser-induced thermal grating spectroscopy based on femtosecond laser multi-photon absorption

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria Ruchkina ◽  
Dina Hot ◽  
Pengji Ding ◽  
Ali Hosseinnia ◽  
Per-Erik Bengtsson ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Laser Pulses ◽  
Photon Absorption ◽  
Gas Flows ◽  
Single Shot ◽  
Photon Excitation ◽  
Fs Laser ◽  
Thermal Grating ◽  
Grating Spectroscopy ◽  
First Time

AbstractLaser-induced grating spectroscopy (LIGS) is for the first time explored in a configuration based on the crossing of two focused femtosecond (fs) laser pulses (800-nm wavelength) and a focused continuous-wave (cw) laser beam (532-nm wavelength). A thermal grating was formed by multi-photon absorption of the fs-laser pulses by $$\hbox {N}_{{2}}$$ N 2 with a pulse energy around 700 $$\upmu $$ μ J ($$\sim $$ ∼ 45 TW/$$\hbox {cm}^{2}$$ cm 2 ). The feasibility of this LIGS configuration was investigated for thermometry in heated nitrogen gas flows. The temperature was varied from room temperature up to 750 K, producing strong single-shot LIGS signals. A model based on the solution of the linearized hydrodynamic equations was used to extract temperature information from single-shot experimental data, and the results show excellent agreement with the thermocouple measurements. Furthermore, the fluorescence produced by the fs-laser pulses was investigated. This study indicates an 8-photon absorption pathway for $$\hbox {N}_{{2}}$$ N 2 in order to reach the $$\hbox {B}^{3}\Pi _{g}$$ B 3 Π g state from the ground state, and 8 + 5 photon excitation to reach the $$\hbox {B}^{2}\Sigma _{u}^{+}$$ B 2 Σ u + state of the $$\hbox {N}_{2}^{+}$$ N 2 + ion. At pulse energies higher than 1 mJ, the LIGS signal was disturbed due to the generation of plasma. Additionally, measurements in argon gas and air were performed, where the LIGS signal for argon shows lower intensity compared to air and $$\hbox {N}_{{2}}$$ N 2 .

The application of inexpensive and synthetic simple electrocatalyst CuFe-MoC@NG in immunosensor

The Analyst ◽  
2021 ◽  
Author(s):  
Lisha Mei ◽  
Wentang Zhao ◽  
Yiju Song ◽  
Li Zhang ◽  
Mengmeng Zhang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Precious Metal ◽  
Doped Graphene ◽  
One Step ◽  
Metal Materials ◽  
First Time

In this study, we used inexpensive and synthetic simple electrocatalysts replacement conventional precious metal materials to reduce hydrogen peroxide (H2O2). We first time developed N-doped graphene-coated CuFe@MoC using one-step calcination...

Farringtonite as an efficient catalyst for linear-chain α-olefin epoxidation with aqueous hydrogen peroxide

2021 ◽  
Author(s):  
Xingyu Yang ◽  
Xu Li ◽  
Jinxiang Dong
Keyword(s):  
Hydrogen Peroxide ◽  
Transition Metals ◽  
Linear Chain ◽  
Olefin Epoxidation ◽  
Aqueous Hydrogen Peroxide ◽  
Efficient Catalyst ◽  
First Time

A convenient, scalable, benign, and efficient epoxidation method based on farringtonite, without the use of transition metals, was developed for the first time.

scholarly journals NH<sub>3</sub>-promoted hydrolysis of NO<sub>2</sub> induces explosive growth in HONO

2018 ◽  
Author(s):  
Wanyun Xu ◽  
Ye Kuang ◽  
Chunsheng Zhao ◽  
Jiangchuan Tao ◽  
Gang Zhao ◽  
...  
Keyword(s):  
North China Plain ◽  
North China ◽  
Ph Value ◽  
Primary Source ◽  
Field Measurements ◽  
Oh Radicals ◽  
The North ◽  
The North China Plain ◽  
First Time ◽  
Hydrolysis Of

Abstract. The study of atmospheric nitrous acid (HONO), which is the primary source of OH radicals, is crucial to atmospheric photochemistry and heterogeneous chemical processes. The heterogeneous NO2 chemistry under haze conditions was pointed out to be one of the missing sources of HONO on the North China Plain, producing sulfate and nitrate in the process. However, controversy exists between various proposed mechanisms, mainly debating on whether SO2 directly takes part in the HONO production process and what roles NH3 and the pH value play in it. In this paper, never before seen explosive HONO production (maximum rate: 16 ppb/hour) was reported and evidence was found for the first time in field measurements during fog episodes (usually with pH > 5) and haze episodes under high relative humidity (usually with pH 

scholarly journals Ultramicrosensors based on transition metal hexacyanoferrates for scanning electrochemical microscopy

2013 ◽  
Vol 4 ◽  
pp. 649-654 ◽  
Author(s):  
Maria A Komkova ◽  
Angelika Holzinger ◽  
Andreas Hartmann ◽  
Alexei R Khokhlov ◽  
Christine Kranz ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Detection Limit ◽  
Transition Metal ◽  
Prussian Blue ◽  
Electrochemical Deposition ◽  
Mixed Layer ◽  
Scanning Electrochemical Microscopy ◽  
The Stability ◽  
Mixed Layers ◽  
Electrochemical Microscopy

We report here a way for improving the stability of ultramicroelectrodes (UME) based on hexacyanoferrate-modified metals for the detection of hydrogen peroxide. The most stable sensors were obtained by electrochemical deposition of six layers of hexacyanoferrates (HCF), more specifically, an alternating pattern of three layers of Prussian Blue and three layers of Ni–HCF. The microelectrodes modified with mixed layers were continuously monitored in 1 mM hydrogen peroxide and proved to be stable for more than 5 h under these conditions. The mixed layer microelectrodes exhibited a stability which is five times as high as the stability of conventional Prussian Blue-modified UMEs. The sensitivity of the mixed layer sensor was 0.32 A·M−1·cm−2, and the detection limit was 10 µM. The mixed layer-based UMEs were used as sensors in scanning electrochemical microscopy (SECM) experiments for imaging of hydrogen peroxide evolution.

An experimental and theoretical study of the kinetics of the reaction between 3-hydroxy-3-methyl-2-butanone and OH radicals

RSC Advances ◽  
2015 ◽  
Vol 5 (34) ◽  
pp. 26559-26568 ◽  
Author(s):  
Angappan Mano Priya ◽  
Gisèle El Dib ◽  
Lakshmipathi Senthilkumar ◽  
Chantal Sleiman ◽  
Alexandre Tomas ◽  
...  
Keyword(s):  
Rate Constants ◽  
Theoretical Study ◽  
Oh Radicals ◽  
First Time ◽  
Kinetics Of

Absolute experimental and theoretical rate constants are determined for the first time for the reaction of 3-hydroxy-3-methyl-2-butanone with OH as a function of temperature. The atmospheric implications are discussed.

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