Applications and Optoelectronic Methods of Detection of Ammonia

Chambers, Paul; Lyons, W. Berry; Sun, Tong; Grattan, Kenneth T. V.

doi:10.5772/19669

Cited by 5 publications

(6 citation statements)

References 38 publications

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“…peak was related to the absorption of water, 12 which was the main component in both the field and concentrated latices. In contrast, the spectra obtained from the FT-NIR spectrometer (Figure 4) clearly revealed the absorption bands due to water at 6897 cm -1 (1450 nm) and 5154 cm -1 (1940 nm).…”

Section: Nir Spectra For Latexmentioning

confidence: 99%

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Rapid Determination of Alkalinity (Ammonia Content) in Para Rubber Latex Using Portable and Fourier Transform-Near Infrared Spectrometers

Narongwongwattana

Rittiron

Hock³

2015

Journal of Near Infrared Spectroscopy

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Ammonia (NH 3) is the main preservative that is added to field and concentrated latices to prevent the deterioration of properties and, in serious cases, coagulation of latex. Almost all factories monitor NH 3 content or alkalinity during processing, as it is an important parameter for trading purposes. Alkalinity is determined by the standard analytical method, acid-based titration, as detailed in ISO 125:2011(E) Natural Rubber Latex Concentrate-Determination of Alkalinity. This method requires a skilled analyst and also the use of chemicals. In addition, the titration involves the subjective determination of the end-point, which may vary with each analyst. Near infrared (NIR) spectroscopy, a rapid, non-chemical and repeatable method, was used in this work. Calibration equations for predicting alkalinity were constructed from the relationship between the absorbance spectra of latex (measured using a portable NIR and a Fourier transform (FT)-NIR spectrometer) and the alkalinity content of the latex. It was found that the best equation obtained using the portable and the FT-NIR spectrometer could be used to predict alkalinity in latex with a coefficient of determination, standard error of prediction and ratio of standard error of validation to the standard deviation of 0.63, 0.101% and 1.62, and 0.97, 0.027% and 6.07, respectively. From the statistics testing for performance measurement as detailed in ISO12099:2010, NIR-predicted values were no different from actual values at the 95% confident interval. Moreover, the best equation obtained from the more reliable calibration achieved using the FT-NIR spectrometer is attributed to the longer wavelength range.

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Section: Nir Spectra For Latexmentioning

confidence: 99%

“…This peak was similar to a specific peak of ammonia at 6573 cm -1 , which was mentioned by Zachariassen et al 10 In addition, another important variable appeared at 5015 cm -1 , corresponding to ammonia absorption at 5291-5784 cm -1 (1890-2090 nm). 12…”

Section: Statistics For Performance Measurementmentioning

confidence: 99%

Rapid Determination of Alkalinity (Ammonia Content) in Para Rubber Latex Using Portable and Fourier Transform-Near Infrared Spectrometers

Narongwongwattana

Rittiron

Hock³

2015

Journal of Near Infrared Spectroscopy

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“…Molecular nitrogen is largely transparent to visible radiation [ 21 ]. Ammonia molecules absorb the ultraviolet and infrared light only [ 22 ]. In our case the visible radiation in not absorbed in the gas phase by mixtures with ammonia and nitrogen.…”

Section: Resultsmentioning

confidence: 99%

Dynamic Control of Adsorption Sensitivity for Photo-EMF-Based Ammonia Gas Sensors Using a Wireless Network

Vashpanov

Choo

Kim

2011

Sensors

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This paper proposes an adsorption sensitivity control method that uses a wireless network and illumination light intensity in a photo-electromagnetic field (EMF)-based gas sensor for measurements in real time of a wide range of ammonia concentrations. The minimum measurement error for a range of ammonia concentration from 3 to 800 ppm occurs when the gas concentration magnitude corresponds with the optimal intensity of the illumination light. A simulation with LabView-engineered modules for automatic control of a new intelligent computer system was conducted to improve measurement precision over a wide range of gas concentrations. This gas sensor computer system with wireless network technology could be useful in the chemical industry for automatic detection and measurement of hazardous ammonia gas levels in real time.

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“…As per American Industrial Hygiene Association (AIHA) emergency response planning guideline, exposure above 300 ppm of NH 3 is dangerous to humans 5 . The Occupational Safety and Health Administration (OSHA) limits the NH 3 8-h total weighted average exposure to 25 ppm for human beings 6 , 7 . Various ammonia gas sensors have been developed which include—chemiresistive sensors 8 – 10 , optical sensors 11 , 12 , electrochemical sensors, surface acoustic wave sensors 13 – 15 , etc.…”

Section: Introductionmentioning

confidence: 99%

Three-dimensional platinum nanoparticle-based bridges for ammonia gas sensing

Isaac

Reiprich

Schlag

et al. 2021

Sci Rep

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This study demonstrates the fabrication of self-aligning three-dimensional (3D) platinum bridges for ammonia gas sensing using gas-phase electrodeposition. This deposition scheme can guide charged nanoparticles to predetermined locations on a surface with sub-micrometer resolution. A shutter-free deposition is possible, preventing the use of additional steps for lift-off and improving material yield. This method uses a spark discharge-based platinum nanoparticle source in combination with sequentially biased surface electrodes and charged photoresist patterns on a glass substrate. In this way, the parallel growth of multiple sensing nodes, in this case 3D self-aligning nanoparticle-based bridges, is accomplished. An array containing 360 locally grown bridges made out of 5 nm platinum nanoparticles is fabricated. The high surface-to-volume ratio of the 3D bridge morphology enables fast response and room temperature operated sensing capabilities. The bridges are preconditioned for ~ 24 h in nitrogen gas before being used for performance testing, ensuring drift-free sensor performance. In this study, platinum bridges are demonstrated to detect ammonia (NH3) with concentrations between 1400 and 100 ppm. The sensing mechanism, response times, cross-sensitivity, selectivity, and sensor stability are discussed. The device showed a sensor response of ~ 4% at 100 ppm NH3 with a 70% response time of 8 min at room temperature.

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Applications and Optoelectronic Methods of Detection of Ammonia

Cited by 5 publications

References 38 publications

Rapid Determination of Alkalinity (Ammonia Content) in Para Rubber Latex Using Portable and Fourier Transform-Near Infrared Spectrometers

Rapid Determination of Alkalinity (Ammonia Content) in Para Rubber Latex Using Portable and Fourier Transform-Near Infrared Spectrometers

Dynamic Control of Adsorption Sensitivity for Photo-EMF-Based Ammonia Gas Sensors Using a Wireless Network

Three-dimensional platinum nanoparticle-based bridges for ammonia gas sensing

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