scholarly journals HONO measurement by differential photolysis

2016 ◽  
Vol 9 (6) ◽  
pp. 2483-2495 ◽  
Author(s):  
Chris Reed ◽  
Charlotte A. Brumby ◽  
Leigh R. Crilley ◽  
Louisa J. Kramer ◽  
William J. Bloss ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Fourier Transform ◽  
Solid State ◽  
Ir Spectroscopy ◽  
Nitrous Acid ◽  
Fast Time ◽  
Ft Ir ◽  
Simulation Chamber ◽  
Ft Ir Spectroscopy

Abstract. Nitrous acid (HONO) has been quantitatively measured in situ by differential photolysis at 385 and 395 nm, and subsequent detection as nitric oxide (NO) by the chemiluminescence reaction with ozone (O3). The technique has been evaluated by Fourier transform infrared (FT-IR) spectroscopy to provide a direct HONO measurement in a simulation chamber and compared side by side with a long absorption path optical photometer (LOPAP) in the field. The NO–O3 chemiluminescence technique is robust, well characterized, and capable of sampling at low pressure, whilst solid-state converter technology allows for unattended in situ HONO measurements in combination with fast time resolution and response.

scholarly journals HONO Measurement by Differential Photolysis

2016 ◽  
Author(s):  
C. Reed ◽  
C. A. Brumby ◽  
L. R. Crilley ◽  
L. J. Kramer ◽  
W. J. Bloss ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Solid State ◽  
Time Resolution ◽  
Nitrous Acid ◽  
Low Pressure ◽  
Fast Time ◽  
Absorption Path ◽  
Ft Ir ◽  
Simulation Chamber

Abstract. Nitrous acid (HONO) has been quantitatively measured in-situ by differential photolysis at 385 and 395 nm and subsequent detection as nitric oxide (NO) by the chemiluminescence reaction with ozone (O3). The technique has been evaluated by FT-IR to provide a direct HONO measurement in a simulation chamber, and compared side-by-side with a LOng Absorption Path Optical Photometer (LOPAP) in the field. The NO/O3 chemiluminescence technique is robust, well characterized and capable of sampling at low pressure whilst solid-state converter technology allows for unattended in-situ HONO measurements in combination with fast time resolution and response.

Thermal Decomposition Products of Fiberglass Composites: A Fourier Transform Infrared Analysis

1997 ◽  
Vol 15 (2) ◽  
pp. 108-125 ◽  
Author(s):  
Karen Kinsella ◽  
James R. Markham ◽  
Chad M. Nelson ◽  
Thomas R. Burkholder
Keyword(s):  
Nitric Oxide ◽  
Thermal Decomposition ◽  
Carbon Monoxide ◽  
Fourier Transform ◽  
Ir Spectroscopy ◽  
Fire Safety ◽  
Fourier Transform Infrared ◽  
Decomposition Products ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Decomposition products of fiberglass composites used in construc tion were identified using Fourier transform infrared (FT-IR) spectroscopy. This bench-scale study concentrated on identification and quantification of toxic species. Identifying compounds evolved during thermal decomposition provides data to develop early fire detection systems as well as evaluate product fire safety performance. Material fire behavior depends on many factors. Ventila tion, radiant heat flux, and chemical composition are three factors that can be modeled. Physical observations of composites during thermal decomposition with simultaneous identification and quantification of evolved gases offer re searchers in both material development and fire safety an advancement in the state-of-the-art for material testing. Gas analysis by FT-IR spectroscopy iden tified toxic effluent species over a wide range of composite exposure tempera tures (100 to 1000 ° C), during pyrolysis and combustion. Fiberglass composites with melamine, epoxy, and silicone resins were profiled. Formaldehyde, meth anol, carbon monoxide, nitric oxide, methane, and benzene were identified by the spectral analysis prior to physical evidence of decomposition. Toxic concen trations of formaldehyde, carbon monoxide, nitric oxide, ammonia, and hydro gen cyanide were observed as thermal decomposition progressed.

scholarly journals Mesoporous Zirconia Coating for Sensing Applications Using Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Spectroscopy

2021 ◽  
pp. 000370282110571
Author(s):  
Dominik Wacht ◽  
Mauro David ◽  
Borislav Hinkov ◽  
Hermann Detz ◽  
Andreas Schwaighofer ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Ir Spectroscopy ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
In Situ Monitoring ◽  
Zirconia Coating ◽  
Mesoporous Zirconia ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Mid-infrared attenuated total reflection (ATR) spectroscopy is a powerful tool for in situ monitoring of various processes. Mesoporous silica, an extensively studied material, has already been applied in sensing schemes due to its high surface area and tunable surface chemistry. However, its poor chemical stability in aqueous solutions at pH values higher than 8 and strong absorption below 1250 cm−1 limits its range of applications. To circumvent these problems, a mesoporous zirconia coating on ATR crystals was developed. Herein, the synthesis, surface modification, and characterization of ordered mesoporous zirconia films on Si wafers and Si-ATR crystals are presented. The modified coating was applied in sensing schemes using aromatic and aliphatic nitriles in aqueous solution as organic pollutants. The mesoporous zirconia coating shows strong chemical resistance when kept in alkaline solution for 72 h. The success of surface modification is confirmed using Fourier transform infrared (FT-IR) spectroscopy and contact angle measurements. Benzonitrile and valeronitrile in water are used as model analytes to evaluate the enrichment performance of the film. The experimental results are fitted using Freundlich isotherms, and enrichment factors of 162 and 26 are calculated for 10 mg L−1 benzonitrile and 25 mg L−1 valeronitrile in water, respectively. Limits of detection of 1 mg L−1 for benzonitrile and 11 mg L−1 for valeronitrile are obtained. The high chemical stability of this coating allows application in diverse fields such as catalysis with the possibility of in situ monitoring using FT-IR spectroscopy.

scholarly journals Bacterial Typing and Identification Based on Fourier Transform Infrared Spectroscopy

2020 ◽  
Author(s):  
Huayan Yang ◽  
Fangling Wu ◽  
Fuxin Xu ◽  
Keqi Tang ◽  
Chuanfan Ding ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Ir Spectroscopy ◽  
Bacterial Culture ◽  
Clinical Laboratory ◽  
Fourier Transform Infrared ◽  
Identification Accuracy ◽  
Bacterial Typing ◽  
Typical Experiment ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Abstract Fourier transform infrared (FT-IR) spectroscopy is a label-free and highly sensitive technique that provides complete information on the chemical composition of biological samples. The bacterial FT-IR signals are extremely specific and highly reproducible fingerprint-like patterns, making FT-IR an efficient tool for bacterial typing and identification. Due to the low cost and high flux, FT-IR has been widely used in hospital hygiene management for infection control, epidemiological studies, and routine bacterial determination of clinical laboratory values. However, the typing and identification accuracy could be affected by many factors, and the bacterial FT-IR data from different laboratories are usually not comparable. A standard protocol is required to improve the accuracy of FT-IR-based typing and identification. Here, we detail the principles and procedures of bacterial typing and identification based on FT-IR spectroscopy, including bacterial culture, sample preparation, instrument operation, spectra collection, spectra preprocessing, and mathematical data analysis. Without bacterial culture, a typical experiment generally takes <2 h.

scholarly journals Monitoring the Interfacial Polymerization of Piperazine and Trimesoyl Chloride with Hydrophilic Interlayer or Macromolecular Additive by in-situ FT-IR Spectroscopy

2019 ◽  
Author(s):  
Xi Yang
Keyword(s):  
Ir Spectroscopy ◽  
Reaction Rate ◽  
Interfacial Polymerization ◽  
Reaction System ◽  
Reaction Rates ◽  
Water Permeation ◽  
Ft Ir ◽  
Trimesoyl Chloride ◽  
Ft Ir Spectroscopy

The interfacial polymerization (IP) of piperazine (PIP) and trimesoyl chloride (TMC) has been extensively utilized to synthesize the nanofiltration (NF) membrane. However, it is still a huge challenge to monitor the IP reaction, because of the fast reaction rate and the formed ultra-thin film. Herein, two effective strategies are applied to reduce the IP reaction rate: (1) the introduction of hydrophilic interlayers between the porous substrate and the formed polyamide layer; (2) the addition of macromolecular additives in the aqueous solution of PIP. As a result, in-situ FT-IR spectroscopy was firstly used to monitor the IP reaction of PIP/TMC reaction system, with hydrophilic interlayers or macromolecular additives. Moreover, we study the formed polyamide layer growth on the substrate, in a real-time manner. The in-situ FT-IR experimental results confirm that the IP reaction rates are effectively suppressed and the formed polyamide thickness reduces from 138&plusmn;24 nm to 46&plusmn;2 nm. Furthermore, the optimized NF membrane with excellent performance are consequently obtained, which include the boosted water permeation flux about 141~238 (L&middot;m2&middot;h/MPa) and superior salt rejection of Na2SO4 &gt; 98.4%.

Sign in / Sign up

Export Citation Format

Share Document