1
|
Xygkis M, Linaraki AN, Toutoudaki EN, Katsoprinakis GE, Rakitzis TP. Absorption coefficients and scattering losses of TGG, TGP, KTF, FS, and CeF 3 magneto-optical crystals in the visible via cavity ring-down spectroscopy. APPLIED OPTICS 2023; 62:7730-7735. [PMID: 37855481 DOI: 10.1364/ao.496780] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 09/20/2023] [Indexed: 10/20/2023]
Abstract
We demonstrate a method for determining small absorption coefficients and surface-scattering losses of crystals using cavity ring-down spectroscopy and perform measurements on magneto-optical crystals of terbium gallium garnet (TGG), terbium gallium phosphate (TGP), fused silica (FS), potassium terbium fluoride (KTF), and C e F 3 at 532 and 634 nm. Surface scattering is distinguished from absorption losses by using crystals of different lengths. A figure of merit (FoM) for magneto-optical crystals is defined to evaluate their suitability as intracavity optics in optical cavity applications. It is found that TGP has the highest FoM for crystal lengths up to ∼10m m, whereas C e F 3 and FS potentially outperform TGP for longer crystals. Single-pass applications are also briefly discussed.
Collapse
|
2
|
Shadman S, Miller TW, Yalin AP. Open-Path Laser Absorption Sensor for Mobile Measurements of Atmospheric Ammonia. SENSORS (BASEL, SWITZERLAND) 2023; 23:6498. [PMID: 37514791 PMCID: PMC10385541 DOI: 10.3390/s23146498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/13/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023]
Abstract
Anthropogenic emissions of ammonia to the atmosphere, particularly those from agricultural sources, can be damaging to the environment and human health and can drive a need for sensor technologies that can be used to detect and quantify the emissions. Mobile sensing approaches that can be deployed on ground-based or aerial vehicles can provide scalable solutions for high throughput measurements but require relatively compact and low-power sensor systems. This contribution presents an ammonia sensor based on wavelength modulation spectroscopy (WMS) integrated with a Herriott multi-pass cell and a quantum cascade laser (QCL) at 10.33 µm oriented to mobile use. An open-path configuration is used to mitigate sticky-gas effects and achieve high time-response. The final sensor package is relatively small (~20 L), lightweight (~3.5 kg), battery-powered (<30 W) and operates autonomously. Details of the WMS setup and analysis method are presented along with laboratory tests showing sensor accuracy (<~2%) and precision (~4 ppb in 1 s). Initial field deployments on both ground vehicles and a fixed-wing unmanned aerial vehicle (UAV) are also presented.
Collapse
Affiliation(s)
- Soran Shadman
- Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80525, USA
| | | | - Azer P Yalin
- Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80525, USA
| |
Collapse
|
3
|
Sharma A, Kumar R, Varadwaj P. Smelling the Disease: Diagnostic Potential of Breath Analysis. Mol Diagn Ther 2023; 27:321-347. [PMID: 36729362 PMCID: PMC9893210 DOI: 10.1007/s40291-023-00640-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/11/2023] [Indexed: 02/03/2023]
Abstract
Breath analysis is a relatively recent field of research with much promise in scientific and clinical studies. Breath contains endogenously produced volatile organic components (VOCs) resulting from metabolites of ingested precursors, gut and air-passage bacteria, environmental contacts, etc. Numerous recent studies have suggested changes in breath composition during the course of many diseases, and breath analysis may lead to the diagnosis of such diseases. Therefore, it is important to identify the disease-specific variations in the concentration of breath to diagnose the diseases. In this review, we explore methods that are used to detect VOCs in laboratory settings, VOC constituents in exhaled air and other body fluids (e.g., sweat, saliva, skin, urine, blood, fecal matter, vaginal secretions, etc.), VOC identification in various diseases, and recently developed electronic (E)-nose-based sensors to detect VOCs. Identifying such VOCs and applying them as disease-specific biomarkers to obtain accurate, reproducible, and fast disease diagnosis could serve as an alternative to traditional invasive diagnosis methods. However, the success of VOC-based identification of diseases is limited to laboratory settings. Large-scale clinical data are warranted for establishing the robustness of disease diagnosis. Also, to identify specific VOCs associated with illness states, extensive clinical trials must be performed using both analytical instruments and electronic noses equipped with stable and precise sensors.
Collapse
Affiliation(s)
- Anju Sharma
- Systems Biology Lab, Indian Institute of Information Technology, Allahabad, Uttar Pradesh, India
| | - Rajnish Kumar
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Uttar Pradesh, Lucknow Campus, Lucknow, India
| | - Pritish Varadwaj
- Systems Biology Lab, Indian Institute of Information Technology, Allahabad, Uttar Pradesh, India.
| |
Collapse
|
4
|
Lee J, Oh MK. Real-time ultrasensitive detection of ammonia gas using a compact CRDS spectrometer. APPLIED OPTICS 2023; 62:1357-1363. [PMID: 36821239 DOI: 10.1364/ao.477575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 01/14/2023] [Indexed: 06/18/2023]
Abstract
Trace-level ammonia gas in air was analyzed using a fiber-based compact cavity ring-down spectrometer (CRDS). For the compact spectrometer, a 20 cm linear cavity with two high reflectivity (>99.999%) mirrors was employed. The laser frequency was locked to the cavity resonance by using frequency shifted (160 MHz) optical feedback. For N H 3 detection, a strong absorption band at 1513.98 nm with an absorption cross section of 3.3⋅10-21 c m/m o l e c u l e was used. As a result, a detection sensitivity of ∼0.1p p b (3-σ) was achieved for N H 3 within 10 s.
Collapse
|
5
|
Shang Z, Li S, Li B, Wu H, Sampaolo A, Patimisco P, Spagnolo V, Dong L. Quartz-enhanced photoacoustic NH 3 sensor exploiting a large-prong-spacing quartz tuning fork and an optical fiber amplifier for biomedical applications. PHOTOACOUSTICS 2022; 26:100363. [PMID: 35574186 PMCID: PMC9096678 DOI: 10.1016/j.pacs.2022.100363] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 04/24/2022] [Accepted: 04/28/2022] [Indexed: 05/24/2023]
Abstract
A sensor system for exhaled ammonia (NH3) monitoring exploiting quartz-enhanced photoacoustic spectroscopy (QEPAS) was demonstrated. An erbium-doped fiber amplifier (EDFA) with an operating frequency band targeting an NH3 absorption line falling at 1531.68 nm and capable to emit up to 3 W of optical power was employed. A custom T-shaped grooved QTF with prong spacing of 1 mm was designed and realized to allow a proper focusing of the high-power optical beam exiting the EDFA between the prongs. The performance of the realized sensor system was optimized in terms of spectrophone parameters, laser power and modulation current, resulting in a NH3 minimum detectable concentration of 14 ppb at 1 s averaging time, corresponding to a normalized noise equivalent absorption coefficient (NNEA) of 8.15 × 10-9 cm-1 W/√Hz. Continuous measurements of the NH3 level exhaled by 3 healthy volunteers was carried out to demonstrate the potentiality of the developed sensor for breath analysis applications.
Collapse
Affiliation(s)
- Zhijin Shang
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, PR China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, PR China
| | - Shangzhi Li
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, PR China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, PR China
| | - Biao Li
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, PR China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, PR China
| | - Hongpeng Wu
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, PR China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, PR China
| | - Angelo Sampaolo
- PolySense Lab-Dipartimento Interateneo di Fisica, University and Politecnico of Bari, Via Amendola 173, Bari, Italy
| | - Pietro Patimisco
- PolySense Lab-Dipartimento Interateneo di Fisica, University and Politecnico of Bari, Via Amendola 173, Bari, Italy
| | - Vincenzo Spagnolo
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, PR China
- PolySense Lab-Dipartimento Interateneo di Fisica, University and Politecnico of Bari, Via Amendola 173, Bari, Italy
| | - Lei Dong
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, PR China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, PR China
| |
Collapse
|
6
|
Kim YJ, Kim DH, Choi JS, Yim JH. A multi-functional ammonia gas and strain sensor with 3D-printed thermoplastic polyurethane-polypyrrole composites. POLYMER 2022. [DOI: 10.1016/j.polymer.2021.124490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
|
7
|
Rajapaksha RD, Tehrani MW, Rule AM, Harb CC. A Rapid and Sensitive Chemical Screening Method for E-Cigarette Aerosols Based on Runtime Cavity Ringdown Spectroscopy. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:8090-8096. [PMID: 34018733 DOI: 10.1021/acs.est.0c07325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Growing demand of Juul and other electronic cigarettes, despite critical knowledge gaps about their chemical composition, has led to concerns regarding their potential health effects. We introduce a novel analytical approach, runtime cavity ringdown spectroscopy (rtCRDS) for rapid detection of oxidative products in e-cigarette aerosols, to facilitate the study of aerosol from a single puff of e-liquid. We report a systematic investigation of three flavors of commercial Juul pods (Virginia tobacco, mango, and menthol) and known commercial e-liquid ingredients (propylene glycol (PG), vegetable glycerin (VG), nicotine, ethyl maltol, benzoic acid, and nicotine benzoate) vaped using Juul devices. Juul e-liquids and neat chemical additives spiked into a 30:70 PG/VG solution were vaped and their aerosols were collected in 1-L Tedlar gas bags and analyzed using rtCRDS. Acetaldehyde, formaldehyde, and acetone were identified as primary oxidative products in aerosolized PG/VG. Ethanol was detected as a major constituent of the three commercial Juul flavors. Spectral intensities of carbonyl compounds increased with the addition of spikes, benzoic acid, ethyl maltol, and nicotine to PG/VG, suggesting that oxidative product generation increases with common additives. The method of direct, rapid analysis of e-cig aerosols introduced here can be used to complement traditional methods in vaping exposures.
Collapse
Affiliation(s)
| | - Mina W Tehrani
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Ana M Rule
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Charles C Harb
- RingIR, 609 Broadway Blvd NE, Albuquerque, New Mexico 87102, United States
| |
Collapse
|
8
|
Sensors for the detection of ammonia as a potential biomarker for health screening. Sci Rep 2021; 11:7185. [PMID: 33785837 PMCID: PMC8009942 DOI: 10.1038/s41598-021-86686-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 03/17/2021] [Indexed: 02/06/2023] Open
Abstract
The presence of ammonia within the body has long been linked to complications stemming from the liver, kidneys, and stomach. These complications can be the result of serious conditions such as chronic kidney disease (CKD), peptic ulcers, and recently COVID-19. Limited liver and kidney function leads to increased blood urea nitrogen (BUN) within the body resulting in elevated levels of ammonia in the mouth, nose, and skin. Similarly, peptic ulcers, commonly from H. pylori, result in ammonia production from urea within the stomach. The presence of these biomarkers enables a potential screening protocol to be considered for frequent, non-invasive monitoring of these conditions. Unfortunately, detection of ammonia in these mediums is rather challenging due to relatively small concentrations and an abundance of interferents. Currently, there are no options available for non-invasive screening of these conditions continuously and in real-time. Here we demonstrate the selective detection of ammonia using a vapor phase thermodynamic sensing platform capable of being employed as part of a health screening protocol. The results show that our detection system has the remarkable ability to selectively detect trace levels of ammonia in the vapor phase using a single catalyst. Additionally, detection was demonstrated in the presence of interferents such as carbon dioxide (CO2) and acetone common in human breath. These results show that our thermodynamic sensors are well suited to selectively detect ammonia at levels that could potentially be useful for health screening applications.
Collapse
|
9
|
Li H, Duan T, Sher O, Han Y, Papadakis R, Grigoriev A, Ahuja R, Leifer K. Fabrication of BP2T functionalized graphene via non-covalent π–π stacking interactions for enhanced ammonia detection. RSC Adv 2021; 11:35982-35987. [PMID: 35492755 PMCID: PMC9043234 DOI: 10.1039/d1ra06879b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 11/01/2021] [Indexed: 11/21/2022] Open
Abstract
Graphene has stimulated great enthusiasm in a variety of fields, while its chemically inert surface still remains challenging for functionalization towards various applications. Herein, we report an approach to fabricate non-covalently functionalized graphene by employing π–π stacking interactions, which has potentialities for enhanced ammonia detection. 5,5′-Di(4-biphenylyl)-2,2′-bithiophene (BP2T) molecules are used in our work for the non-covalent functionalization through strong π–π interactions of aromatic structures with graphene, and systematic investigations by employing various spectroscopic and microscopic characterization methods confirm the successful non-covalent attachment of the BP2T on the top of graphene. From our gas sensing experiments, the BP2T functionalized graphene is promising for ammonia sensing with a 3-fold higher sensitivity comparing to that of the pristine graphene, which is mainly attributed to the enhanced binding energy between the ammonia and BP2T molecules derived by employing the Langmuir isotherm model. This work provides essential evidence of the π–π stacking interactions between graphene and aromatic molecules, and the reported approach also has the potential to be widely employed in a variety of graphene functionalizations for chemical detection. Non-covalent functionalization of graphene has been achieved by employing π–π stacking interactions, and it is promising for ammonia detection with greatly enhanced sensitivity.![]()
Collapse
Affiliation(s)
- Hu Li
- Shandong Technology Centre of Nanodevices and Integration, School of Microelectronics, Shandong University, 250101 Jinan, China
- Department of Materials Science and Engineering-Ångström, Uppsala University, 75121 Uppsala, Sweden
| | - Tianbo Duan
- Department of Materials Science and Engineering-Ångström, Uppsala University, 75121 Uppsala, Sweden
| | - Omer Sher
- Department of Materials Science and Engineering-Ångström, Uppsala University, 75121 Uppsala, Sweden
| | - Yuanyuan Han
- Department of Materials Science and Engineering-Ångström, Uppsala University, 75121 Uppsala, Sweden
| | | | - Anton Grigoriev
- Department of Physics and Astronomy-Ångström, Uppsala University, 75120 Uppsala, Sweden
| | - Rajeev Ahuja
- Department of Physics and Astronomy-Ångström, Uppsala University, 75120 Uppsala, Sweden
| | - Klaus Leifer
- Department of Materials Science and Engineering-Ångström, Uppsala University, 75121 Uppsala, Sweden
| |
Collapse
|
10
|
Banik GD, Mizaikoff B. Exhaled breath analysis using cavity-enhanced optical techniques: a review. J Breath Res 2020; 14:043001. [PMID: 32969348 DOI: 10.1088/1752-7163/abaf07] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cavity-enhanced absorption spectroscopies (CEAS) have gained importance in a wide range of applications in molecular spectroscopy. The development of optical sensors based on the CEAS techniques coupled with the continuous wave or pulsed laser sources operating in the mid-infrared or near-infrared spectral regime uniquely offers molecularly selective and ultra-sensitive detection of trace species in complex matrices including exhaled human breath. In this review, we discussed recent applications of CEAS for analyzing trace constituents within the exhaled breath matrix facilitating the non-invasive assessment of human health status. Next to a brief discussion on the mechanisms of formation of trace components found in the exhaled breath matrix related to particular disease states, existing challenges in CEAS and future development towards non-invasive clinical diagnostics will be discussed.
Collapse
Affiliation(s)
- Gourab D Banik
- Institute of Analytical and Bioanalytical Chemistry, Ulm University Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | | |
Collapse
|
11
|
Cavity Ring-Down Spectroscopy for Molecular Trace Gas Detection Using A Pulsed DFB QCL Emitting at 6.8 µm. PHOTONICS 2020. [DOI: 10.3390/photonics7030074] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A trace gas sensor based on pulsed cavity ring-down spectroscopy (CRDS) was developed for measurement of the ν4 fundamental vibrational band of ammonia (NH3) centered at 1468.898 cm−1. A pulsed distributed feedback quantum cascade laser (DFB-QCL) operating at 6.8 µm (1470.58 cm−1) quite well covered the absorption band of the ammonia and strong fundamental vibrational absorption bands of different molecular gases in this unexplored region. The cavity was partially evacuated down to 0.4 Atm by a turbo-molecular pump to reduce the partial interference between the NH3 spectra and water near the absorption peak of ammonia. A sensitivity of nine parts per billion was reached for a measurement time of 120 s as well as an optical path length of 226 m. The device demonstrated high spectral performance and versatility due to its wide tuning range, narrow linewidth, and comparatively high-energy mid-IR radiation in the relatively unexplored 6.8 µm region, which is very important for high-resolution spectroscopy of a variety of gases.
Collapse
|
12
|
Han Y, Li W, Chen Z, Jiang H, Hamamoto K. Fabrication and analysis of low-loss silicon high-mesa waveguides. APPLIED OPTICS 2020; 59:4964-4969. [PMID: 32543493 DOI: 10.1364/ao.391604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 04/26/2020] [Indexed: 06/11/2023]
Abstract
Breath sensing is an effective tool for health monitoring. Previously, high-mesa waveguide structures have been proposed by our group for realizing a compact breath-sensing photonic circuit. By using the doped SiO2 as the waveguide core, 50% concentration CO2 has been detected. One issue of preventing parts per million (ppm)-order detection is the low portion of evanescent light (Γair=2.2%) in the doped SiO2 waveguides. In order to realize low propagation loss α and high Γair simultaneously, thin silicon (Si) waveguides with a Γair as high as 37.6% have been proposed and fabricated in this work. A thermal oxidation technique was applied to further reduce α, so that α was decreased from 1.45 to 0.84 and 0.29 to 0.2 dB/cm for the 0.5 and 3-µm-wide waveguide, respectively. According to our analysis, the significantly decreased α is attributed to recovering the damaged Si core and smoothing the waveguide sidewalls. The high Γair and effective loss reduction show a promising potential of applying Si high-mesa waveguides to realize ppm-order sensing.
Collapse
|
13
|
Selvaraj R, Vasa NJ, Nagendra SMS, Mizaikoff B. Advances in Mid-Infrared Spectroscopy-Based Sensing Techniques for Exhaled Breath Diagnostics. Molecules 2020; 25:molecules25092227. [PMID: 32397389 PMCID: PMC7249025 DOI: 10.3390/molecules25092227] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 04/28/2020] [Accepted: 04/29/2020] [Indexed: 01/05/2023] Open
Abstract
Human exhaled breath consists of more than 3000 volatile organic compounds, many of which are relevant biomarkers for various diseases. Although gas chromatography has been the gold standard for volatile organic compound (VOC) detection in exhaled breath, recent developments in mid-infrared (MIR) laser spectroscopy have led to the promise of compact point-of-care (POC) optical instruments enabling even single breath diagnostics. In this review, we discuss the evolution of MIR sensing technologies with a special focus on photoacoustic spectroscopy, and its application in exhaled breath biomarker detection. While mid-infrared point-of-care instrumentation promises high sensitivity and inherent molecular selectivity, the lack of standardization of the various techniques has to be overcome for translating these techniques into more widespread real-time clinical use.
Collapse
Affiliation(s)
- Ramya Selvaraj
- Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036, India;
- Correspondence:
| | - Nilesh J. Vasa
- Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036, India;
| | - S. M. Shiva Nagendra
- Department of Civil Engineering, Indian Institute of Technology Madras, Chennai 600036, India;
| | - Boris Mizaikoff
- Institute of Analytical and Bioanalytical Chemistry, Ulm University, 89081 Ulm, Germany;
| |
Collapse
|
14
|
Tan Y, Kochanov RV, Rothman LS, Gordon IE. Introduction of Water-Vapor Broadening Parameters and Their Temperature-Dependent Exponents Into the HITRAN Database: Part I-CO 2, N 2O, CO, CH 4, O 2, NH 3, and H 2S. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2019; 124:11580-11594. [PMID: 31894194 PMCID: PMC6919420 DOI: 10.1029/2019jd030929] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 09/10/2019] [Accepted: 09/11/2019] [Indexed: 06/10/2023]
Abstract
The amount of water vapor in the terrestrial atmosphere is highly variable both spatially and temporally. In the tropics it sometimes constitutes 4-5% of the atmosphere. At the same time collisional broadening of spectral lines by water vapor is much larger than that by nitrogen and oxygen. Therefore, in order to accurately characterize and model spectra of the atmospheres with significant amounts of water vapor, the line-shape parameters for spectral lines broadened by water vapor are required. In this work, the pressure-broadening parameters (and their temperature-dependent exponents) due to the pressure of water vapor for spectral lines of CO2, N2O, CO, CH4, O2, NH3, and H2S from both experimental and theoretical studies were collected and carefully reviewed. A set of semiempirical models based on these collected data was proposed and then used to estimate water broadening and its temperature dependence for all transitions of selected molecules in the HITRAN2016 database.
Collapse
Affiliation(s)
- Y. Tan
- Atomic and Molecular Physics DivisionHarvard‐Smithsonian Center for AstrophysicsCambridgeMAUSA
- Now at Hefei National Laboratory for Physical Sciences at Microscale, iChem CenterUniversity of Science and Technology of ChinaHefeiChina
| | - R. V. Kochanov
- Atomic and Molecular Physics DivisionHarvard‐Smithsonian Center for AstrophysicsCambridgeMAUSA
- Laboratory of Quantum Mechanics of Molecules and Radiative ProcessesTomsk State UniversityTomskRussia
| | - L. S. Rothman
- Atomic and Molecular Physics DivisionHarvard‐Smithsonian Center for AstrophysicsCambridgeMAUSA
| | - I. E. Gordon
- Atomic and Molecular Physics DivisionHarvard‐Smithsonian Center for AstrophysicsCambridgeMAUSA
| |
Collapse
|
15
|
Lou C, Jing C, Wang X, Chen Y, Zhang J, Hou K, Yao J, Liu X. Near-infrared tunable diode laser absorption spectroscopy-based determination of carbon dioxide in human exhaled breath. BIOMEDICAL OPTICS EXPRESS 2019; 10:5486-5496. [PMID: 31799026 PMCID: PMC6865105 DOI: 10.1364/boe.10.005486] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/22/2019] [Accepted: 09/26/2019] [Indexed: 06/10/2023]
Abstract
A spectroscopic detection system for the accurate monitoring of carbon dioxide (CO2) in exhaled breath was realized by tunable diode laser absorption spectroscopy (TDLAS) in conjunction with a vertical-cavity surface-emitting laser (VCSEL) and a multipass cell with an effective optical path-length of 20 m. The VCSEL diode emitting light with an output power of 0.8 mW, covered the strong absorption line of CO2 at 6330.82 cm-1 by drive-current tuning. The minimum detectable concentration of 0.769‰ for CO2 detection was obtained, and a measurement precision of approximately 100 ppm was achieved with an integration time of 168 s. Real-time online measurements were carried out for the detection of CO2 expirograms from healthy subjects, different concentrations were obtained in dead space and alveolar gas. The exhaled CO2 increased significantly with the increasing physical activity, reaches its maximal value at the beginning of respiratory compensation and then decreased slightly until maximal exercise. The developed measurement system has a great potential to be applied in practice for the detection of pulmonary diseases associated with CO2 retention.
Collapse
Affiliation(s)
- Cunguang Lou
- College of Electronic Information Engineering & Hebei Key Laboratory of Digital Medical Engineering, Hebei University, Baoding 071000, China
- College of Precision Instrument and Optoelectronics Engineering, Institute of Laser and Optoelectronics, Tianjin University, Tianjin 300072, China
| | - Congrui Jing
- College of Electronic Information Engineering & Hebei Key Laboratory of Digital Medical Engineering, Hebei University, Baoding 071000, China
| | - Xin Wang
- College of Electronic Information Engineering & Hebei Key Laboratory of Digital Medical Engineering, Hebei University, Baoding 071000, China
| | - Yuhao Chen
- College of Electronic Information Engineering & Hebei Key Laboratory of Digital Medical Engineering, Hebei University, Baoding 071000, China
| | - Jiantao Zhang
- College of Electronic Information Engineering & Hebei Key Laboratory of Digital Medical Engineering, Hebei University, Baoding 071000, China
| | - Kaixuan Hou
- College of Electronic Information Engineering & Hebei Key Laboratory of Digital Medical Engineering, Hebei University, Baoding 071000, China
| | - Jianquan Yao
- College of Precision Instrument and Optoelectronics Engineering, Institute of Laser and Optoelectronics, Tianjin University, Tianjin 300072, China
| | - Xiuling Liu
- College of Electronic Information Engineering & Hebei Key Laboratory of Digital Medical Engineering, Hebei University, Baoding 071000, China
| |
Collapse
|
16
|
Application of Near-Infrared Optical Feedback Cavity Enhanced Absorption Spectroscopy (OF-CEAS) to the Detection of Ammonia in Exhaled Human Breath. SENSORS 2019; 19:s19173686. [PMID: 31450646 PMCID: PMC6749448 DOI: 10.3390/s19173686] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 08/17/2019] [Accepted: 08/22/2019] [Indexed: 11/23/2022]
Abstract
The qualitative and quantitative analysis to trace gas in exhaled human breath has become a promising technique in biomedical applications such as disease diagnosis and health status monitoring. This paper describes an application of a high spectral resolution optical feedback cavity enhanced absorption spectroscopy (OF-CEAS) for ammonia detection in exhaled human breath, and the main interference of gases such as CO2 and H2O are approximately eliminated at the same time. With appropriate optical feedback, a fibered distributed feedback (DFB) diode laser emitting at 1531.6 nm is locked to the resonance of a V-shaped cavity with a free spectral range (FSR) of 300 MHz and a finesse of 14,610. A minimum detectable absorption coefficient of αmin = 2.3 × 10−9 cm−1 is achieved in a single scan within 5 s, yielding a detection limit of 17 ppb for NH3 in breath gas at low pressure, and this stable system allows the detection limit down to 4.5 ppb when the spectra to be averaged over 16 laser scans. Different from typical CEAS with a static cavity, which is limited by the FSR in frequency space, the attainable spectral resolution of our experimental setup can be up to 0.002 cm−1 owing to the simultaneous laser frequency tuning and cavity dither. Hence, the absorption line profile is more accurate, which is most suitable for low-pressure trace gas detection. This work has great potential for accurate selectivity and high sensitivity applications in human breath analysis and atmosphere sciences.
Collapse
|
17
|
Isensee K, Kröger-Lui N, Petrich W. Biomedical applications of mid-infrared quantum cascade lasers - a review. Analyst 2019; 143:5888-5911. [PMID: 30444222 DOI: 10.1039/c8an01306c] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Mid-infrared spectroscopy has been applied to research in biology and medicine for more than 20 years and conceivable applications have been identified. More recently, these applications have been shown to benefit from the use of quantum cascade lasers due to their specific properties, namely high spectral power density, small beam parameter product, narrow emission spectrum and, if needed, tuning capabilities. This review provides an overview of the achievements and illustrates some applications which benefit from the key characteristics of quantum cascade laser-based mid-infrared spectroscopy using examples such as breath analysis, the investigation of serum, non-invasive glucose monitoring in bulk tissue and the combination of spectroscopy and microscopy of tissue thin sections for rapid histopathology.
Collapse
Affiliation(s)
- Katharina Isensee
- Kirchhoff-Institute for Physics, Heidelberg University, INF 277, 69120 Heidelberg, Germany.
| | | | | |
Collapse
|
18
|
Meng Z, Aykanat A, Mirica KA. Welding Metallophthalocyanines into Bimetallic Molecular Meshes for Ultrasensitive, Low-Power Chemiresistive Detection of Gases. J Am Chem Soc 2018; 141:2046-2053. [DOI: 10.1021/jacs.8b11257] [Citation(s) in RCA: 146] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Zheng Meng
- Department of Chemistry, Burke Laboratory, Dartmouth College, Hanover, New Hampshire 03755, United States
| | - Aylin Aykanat
- Department of Chemistry, Burke Laboratory, Dartmouth College, Hanover, New Hampshire 03755, United States
| | - Katherine A. Mirica
- Department of Chemistry, Burke Laboratory, Dartmouth College, Hanover, New Hampshire 03755, United States
| |
Collapse
|
19
|
Highly sensitive ammonia sensor for diagnostic purpose using reduced graphene oxide and conductive polymer. Sci Rep 2018; 8:18030. [PMID: 30575788 PMCID: PMC6303394 DOI: 10.1038/s41598-018-36468-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 11/22/2018] [Indexed: 01/01/2023] Open
Abstract
In this study, we fabricate ammonia sensors based on hybrid thin films of reduced graphene oxide (RGO) and conducting polymers using the Langmuir-Schaefer (LS) technique. The RGO is first prepared using hydrazine (Hy) and/or pyrrole (Py) as the reducing agents, and the resulting pyrrole-reduced RGO (Py-RGO) is then hybridized with polyaniline (PANI) and/or polypyrrole (PPy) by in-situ polymerization. The four different thin films of Hy-RGO, Py-RGO, Py-RGO/PANI, and Py-RGO/PPy are deposited on interdigitated microelectrodes by the LS techniques, and their structures are characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results of ammonia sensing experiments indicate that the Py-RGO/PANI film exhibits the highest sensor response of these four films, and that it exhibits high reproducibility, high linearity of concentration dependency, and a very low detection limit (0.2 ppm) both in N2 and exhaled air environments. The current gas sensor, therefore, has potential for diagnostic purposes because it has the additional advantages of facile fabrication, ease of use at room temperature, and portability compared to conventional high-sensitivity ammonia sensors.
Collapse
|
20
|
Henderson B, Khodabakhsh A, Metsälä M, Ventrillard I, Schmidt FM, Romanini D, Ritchie GAD, te Lintel Hekkert S, Briot R, Risby T, Marczin N, Harren FJM, Cristescu SM. Laser spectroscopy for breath analysis: towards clinical implementation. APPLIED PHYSICS. B, LASERS AND OPTICS 2018; 124:161. [PMID: 30956412 PMCID: PMC6428385 DOI: 10.1007/s00340-018-7030-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 07/19/2018] [Indexed: 05/08/2023]
Abstract
Detection and analysis of volatile compounds in exhaled breath represents an attractive tool for monitoring the metabolic status of a patient and disease diagnosis, since it is non-invasive and fast. Numerous studies have already demonstrated the benefit of breath analysis in clinical settings/applications and encouraged multidisciplinary research to reveal new insights regarding the origins, pathways, and pathophysiological roles of breath components. Many breath analysis methods are currently available to help explore these directions, ranging from mass spectrometry to laser-based spectroscopy and sensor arrays. This review presents an update of the current status of optical methods, using near and mid-infrared sources, for clinical breath gas analysis over the last decade and describes recent technological developments and their applications. The review includes: tunable diode laser absorption spectroscopy, cavity ring-down spectroscopy, integrated cavity output spectroscopy, cavity-enhanced absorption spectroscopy, photoacoustic spectroscopy, quartz-enhanced photoacoustic spectroscopy, and optical frequency comb spectroscopy. A SWOT analysis (strengths, weaknesses, opportunities, and threats) is presented that describes the laser-based techniques within the clinical framework of breath research and their appealing features for clinical use.
Collapse
Affiliation(s)
- Ben Henderson
- Trace Gas Research Group, Molecular and Laser Physics, IMM, Radboud University, 6525 AJ Nijmegen, The Netherlands
| | - Amir Khodabakhsh
- Trace Gas Research Group, Molecular and Laser Physics, IMM, Radboud University, 6525 AJ Nijmegen, The Netherlands
| | - Markus Metsälä
- Department of Chemistry, University of Helsinki, PO Box 55, 00014 Helsinki, Finland
| | | | - Florian M. Schmidt
- Department of Applied Physics and Electronics, Umeå University, 90187 Umeå, Sweden
| | - Daniele Romanini
- University of Grenoble Alpes, CNRS, LIPhy, 38000 Grenoble, France
| | - Grant A. D. Ritchie
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QZ UK
| | | | - Raphaël Briot
- University of Grenoble Alpes, CNRS, TIMC-IMAG, 38000 Grenoble, France
- Emergency Department and Mobile Intensive Care Unit, Grenoble University Hospital, Grenoble, France
| | - Terence Risby
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, USA
| | - Nandor Marczin
- Section of Anaesthetics, Pain Medicine and Intensive Care, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, UK
- Centre of Anaesthesia and Intensive Care, Semmelweis University, Budapest, Hungary
| | - Frans J. M. Harren
- Trace Gas Research Group, Molecular and Laser Physics, IMM, Radboud University, 6525 AJ Nijmegen, The Netherlands
| | - Simona M. Cristescu
- Trace Gas Research Group, Molecular and Laser Physics, IMM, Radboud University, 6525 AJ Nijmegen, The Netherlands
| |
Collapse
|
21
|
Liu NY, Cay-Durgun P, Lai T, Sprowls M, Thomas L, Lind ML, Forzani E. A Handheld, Colorimetric Optoelectronic Dynamics Analyzer for Measuring Total Ammonia of Biological Samples. IEEE JOURNAL OF TRANSLATIONAL ENGINEERING IN HEALTH AND MEDICINE-JTEHM 2018; 6:2800610. [PMID: 30112251 PMCID: PMC6092083 DOI: 10.1109/jtehm.2018.2840678] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 05/11/2018] [Accepted: 05/20/2018] [Indexed: 12/30/2022]
Abstract
This paper introduces a wireless, solid-state, portable, and automated device capable of measuring the total ammonia [ammonia (NH3) and ammonium (NH4+)] levels of fluids, including biological samples. This device reliably measures the total ammonia of biological samples (e.g., urine) faster than the current ammonia quantification techniques. Medical professionals typically estimate NH4+ levels using error-prone indirect measurement techniques (i.e., urine anion gap), which are time-consuming and are seldom suitable for periodic measurements. Several instantaneous measurements of total ammonia levels in a patient urine could be utilized as an early warning for both acid-base and/or potassium disturbances. Given the device’s operation mechanism, it is able to quantify the total ammonia concentration within a biological sample in only 5 s and can simultaneously transmit data to other devices via Bluetooth. The analytical operation demonstrated high sensitivity, high specificity, fast reversibility, rapid response time, and has enabled the accurate determination of total ammonia concentration in urine samples produced by subjects who had consumed diets of variable protein compositions.
Collapse
Affiliation(s)
- Nai-Yuan Liu
- School for Engineering of Matter, Transport, and EnergyArizona State UniversityTempeAZ85287USA.,Center for Bioelectronics and BiosensorsThe Biodesign Institute, Arizona State UniversityTempeAZ85287USA
| | - Pinar Cay-Durgun
- School for Engineering of Matter, Transport, and EnergyArizona State UniversityTempeAZ85287USA
| | - Tianmiao Lai
- School for Engineering of Matter, Transport, and EnergyArizona State UniversityTempeAZ85287USA.,Center for Bioelectronics and BiosensorsThe Biodesign Institute, Arizona State UniversityTempeAZ85287USA
| | - Mark Sprowls
- School for Engineering of Matter, Transport, and EnergyArizona State UniversityTempeAZ85287USA.,Center for Bioelectronics and BiosensorsThe Biodesign Institute, Arizona State UniversityTempeAZ85287USA
| | - Leslie Thomas
- School for Engineering of Matter, Transport, and EnergyArizona State UniversityTempeAZ85287USA.,Mayo Clinic in Arizona Division of NephrologyScottsdaleAZ85259USA
| | - Mary Laura Lind
- School for Engineering of Matter, Transport, and EnergyArizona State UniversityTempeAZ85287USA.,Center for Bioelectronics and BiosensorsThe Biodesign Institute, Arizona State UniversityTempeAZ85287USA.,Mayo Clinic in Arizona Division of NephrologyScottsdaleAZ85259USA
| | - Erica Forzani
- School for Engineering of Matter, Transport, and EnergyArizona State UniversityTempeAZ85287USA.,Center for Bioelectronics and BiosensorsThe Biodesign Institute, Arizona State UniversityTempeAZ85287USA.,Mayo Clinic in Arizona Division of NephrologyScottsdaleAZ85259USA
| |
Collapse
|
22
|
Maithani S, Mandal S, Maity A, Pal M, Pradhan M. High-resolution spectral analysis of ammonia near 6.2 μm using a cw EC-QCL coupled with cavity ring-down spectroscopy. Analyst 2018; 143:2109-2114. [DOI: 10.1039/c7an02008b] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
High-resolution cavity ring-down spectra of ammonia near 6.2 μm for trace gas sensing and biomedical applications.
Collapse
Affiliation(s)
- Sanchi Maithani
- Department of Chemical
- Biological and Macromolecular Sciences
- S. N. Bose National Centre for Basic Sciences
- Kolkata-700106
- India
| | - Santanu Mandal
- Department of Chemical
- Biological and Macromolecular Sciences
- S. N. Bose National Centre for Basic Sciences
- Kolkata-700106
- India
| | - Abhijit Maity
- Department of Chemical
- Biological and Macromolecular Sciences
- S. N. Bose National Centre for Basic Sciences
- Kolkata-700106
- India
| | - Mithun Pal
- Department of Chemical
- Biological and Macromolecular Sciences
- S. N. Bose National Centre for Basic Sciences
- Kolkata-700106
- India
| | - Manik Pradhan
- Department of Chemical
- Biological and Macromolecular Sciences
- S. N. Bose National Centre for Basic Sciences
- Kolkata-700106
- India
| |
Collapse
|
23
|
Schwaighofer A, Brandstetter M, Lendl B. Quantum cascade lasers (QCLs) in biomedical spectroscopy. Chem Soc Rev 2017; 46:5903-5924. [DOI: 10.1039/c7cs00403f] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This review focuses on the recent applications of QCLs in mid-IR spectroscopy of clinically relevant samples.
Collapse
Affiliation(s)
- Andreas Schwaighofer
- Institute of Chemical Technologies and Analytics
- Vienna University of Technology
- 1060 Vienna
- Austria
| | | | - Bernhard Lendl
- Institute of Chemical Technologies and Analytics
- Vienna University of Technology
- 1060 Vienna
- Austria
| |
Collapse
|
24
|
Recent analytical approaches to detect exhaled breath ammonia with special reference to renal patients. Anal Bioanal Chem 2016; 409:21-31. [PMID: 27595582 DOI: 10.1007/s00216-016-9903-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 07/10/2016] [Accepted: 08/24/2016] [Indexed: 12/15/2022]
Abstract
The ammonia odor from the exhaled breath of renal patients is associated with high levels of blood urea nitrogen. Typically, in the liver, ammonia and ammonium ions are converted into urea through the urea cycle. In the case of renal dysfunction, urea is unable to be removed and that causes a buildup of excessive ammonia. As small molecules, ammonia and ammonium ions can be forced into the blood-lung barrier and occur in exhaled breath. Therefore, people with renal failure have an ammonia (fishy) odor in their exhaled breath. Thus, exhaled breath ammonia can be a potential biomarker for monitoring renal diseases during hemodialyis. In this review, we have summarized the source of ammonia in the breath of end-stage renal disease patient, cause of renal disorders, exhaled breath condensate, and breath sampling. Further, various biosensor approaches to detect exhaled ammonia from renal patients and other ammonia systems are also discussed. We conclude with future perspectives, namely colorimetric-based real-time breathing diagnosis of renal failure, which might be useful for prospective studies.
Collapse
|
25
|
Sur R, Spearrin RM, Peng WY, Strand CL, Jeffries JB, Enns GM, Hanson RK. Line intensities and temperature-dependent line broadening coefficients of Q-branch transitions in the v 2 band of ammonia near 10.4 μm. JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER 2016; 175:90-99. [PMID: 29225373 PMCID: PMC5722251 DOI: 10.1016/j.jqsrt.2016.02.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report measured line intensities and temperature-dependent broadening coefficients of NH3 with Ar, N2, O2, CO2, H2O, and NH3 for nine sQ(J,K) transitions in the ν2 fundamental band in the frequency range 961.5-967.5 cm-1. This spectral region was chosen due to the strong NH3 absorption strength and lack of spectral interference from H2O and CO2 for laser-based sensing applications. Spectroscopic parameters were determined by multi-line fitting using Voigt lineshapes of absorption spectra measured with two quantum cascade lasers in thermodynamically-controlled optical cells. The temperature dependence of broadening was measured over a range of temperatures between 300 and 600 K. These measurements aid the development of mid-infrared NH3 sensors for a broad range of gas mixtures and at elevated temperatures.
Collapse
Affiliation(s)
- Ritobrata Sur
- High Temperature Gasdynamics Laboratory, Thermosciences division, Stanford University, 452 Escondido Mall, Bldg 520, CA 94305, USA
| | - R Mitchell Spearrin
- High Temperature Gasdynamics Laboratory, Thermosciences division, Stanford University, 452 Escondido Mall, Bldg 520, CA 94305, USA
| | - Wen Y Peng
- High Temperature Gasdynamics Laboratory, Thermosciences division, Stanford University, 452 Escondido Mall, Bldg 520, CA 94305, USA
| | - Christopher L Strand
- High Temperature Gasdynamics Laboratory, Thermosciences division, Stanford University, 452 Escondido Mall, Bldg 520, CA 94305, USA
| | - Jay B Jeffries
- High Temperature Gasdynamics Laboratory, Thermosciences division, Stanford University, 452 Escondido Mall, Bldg 520, CA 94305, USA
| | - Gregory M Enns
- High Temperature Gasdynamics Laboratory, Thermosciences division, Stanford University, 452 Escondido Mall, Bldg 520, CA 94305, USA
| | - Ronald K Hanson
- High Temperature Gasdynamics Laboratory, Thermosciences division, Stanford University, 452 Escondido Mall, Bldg 520, CA 94305, USA
| |
Collapse
|
26
|
Dougakiuchi T, Fujita K, Sugiyama A, Ito A, Akikusa N, Edamura T. Broadband tuning of continuous wave quantum cascade lasers in long wavelength (> 10 μm) range. OPTICS EXPRESS 2014; 22:19930-19935. [PMID: 25321203 DOI: 10.1364/oe.22.019930] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Broadband spectral tuning in the long wavelength range (greater than 10 μm) was demonstrated with an external-cavity quantum cascade laser. The tunable wavelength of the laser ranged from 9.5 to 11.4 μm (176 cm(-1); corresponding to 18% of the center wavelength) in continuous wave (cw) operation at room temperature, without any anti-reflection coating. The gain chip based on the anti-crossed dual-upper-state (DAU) design provided a cw lasing up to 300 K, with a low threshold current density of 2.1 kA/cm2. The highly stable broadband spectral tuning and high laser performance were enabled by the spectrally homogeneous gain profile of the anti-crossed DAU active region.
Collapse
|
27
|
Di Natale C, Paolesse R, Martinelli E, Capuano R. Solid-state gas sensors for breath analysis: a review. Anal Chim Acta 2014; 824:1-17. [PMID: 24759744 DOI: 10.1016/j.aca.2014.03.014] [Citation(s) in RCA: 161] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 03/10/2014] [Accepted: 03/12/2014] [Indexed: 01/21/2023]
Abstract
The analysis of volatile compounds is an efficient method to appraise information about the chemical composition of liquids and solids. This principle is applied to several practical applications, such as food analysis where many important features (e.g. freshness) can be directly inferred from the analysis of volatile compounds. The same approach can also be applied to a human body where the volatile compounds, collected from the skin, the breath or in the headspace of fluids, might contain information that could be used to diagnose several kinds of diseases. In particular, breath is widely studied and many diseases can be potentially detected from breath analysis. The most fascinating property of breath analysis is the non-invasiveness of the sample collection. Solid-state sensors are considered the natural complement to breath analysis, matching the non-invasiveness with typical sensor features such as low-cost, easiness of use, portability, and the integration with the information networks. Sensors based breath analysis is then expected to dramatically extend the diagnostic capabilities enabling the screening of large populations for the early diagnosis of pathologies. In the last years there has been an increased attention to the development of sensors specifically aimed to this purpose. These investigations involve both specific sensors designed to detect individual compounds and non-specific sensors, operated in array configurations, aimed at clustering subjects according to their health conditions. In this paper, the recent significant applications of these sensors to breath analysis are reviewed and discussed.
Collapse
Affiliation(s)
- Corrado Di Natale
- Department of Electronic Engineering, University of Rome Tor Vergata, via del Politecnico 1, Roma 00133, Italy.
| | - Roberto Paolesse
- Department of Chemical Science and Technology, University of Rome Tor Vergata, via della Ricerca Scientifica, Roma 00133, Italy
| | - Eugenio Martinelli
- Department of Electronic Engineering, University of Rome Tor Vergata, via del Politecnico 1, Roma 00133, Italy
| | - Rosamaria Capuano
- Department of Electronic Engineering, University of Rome Tor Vergata, via del Politecnico 1, Roma 00133, Italy
| |
Collapse
|
28
|
|
29
|
Detection of volatile organic compounds as biomarkers in breath analysis by different analytical techniques. Bioanalysis 2013; 5:2287-306. [DOI: 10.4155/bio.13.183] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Breath is a rich mixture containing numerous volatile organic compounds at trace amounts (ppbv–pptv level) such as: hydrocarbons, alcohols, ketones, aldehydes, esters or heterocycles. The presence of some of them depends on health status. Therefore, breath analysis might be useful for clinical diagnostics, therapy monitoring and control of metabolic or biochemical cell cycle products. This Review presents an update on the latest developments in breath analysis applied to diagnosing different diseases with the help of high-quality equipment. Efforts were made to fully and accurately describe traditional and modern techniques used to determine the components of breath. The techniques were compared in terms of design, function and also detection limit of different volatile organic compounds. GC with different detectors, MS, optical sensor and laser spectroscopic detection techniques are also discussed.
Collapse
|
30
|
Kaucikas M, Barber J, Van Thor JJ. Polarization sensitive ultrafast mid-IR pump probe micro-spectrometer with diffraction limited spatial resolution. OPTICS EXPRESS 2013; 21:8357-8370. [PMID: 23571925 DOI: 10.1364/oe.21.008357] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A setup of ultrafast transient infrared IR spectrometer is described in this paper that employed Schwarzschild objectives to focus the probe beam to a diffraction limited spot. Thus measurements were performed with very high spatial resolution in the mid-IR spectral region. Furthermore, modulating the polarization of the probe light enabled detecting transient dichroism of the sample. These capabilities of the setup were applied to study transient absorption of Photosystem II core complex and to image an organized film of methylene blue chloride dye. Moreover, a study of noise sources in a pump probe measurement is presented. The predicted noise level of the current setup was 8.25 μOD in 10(4) acquisitions and compared very well with the experimental observation of 9.6 μOD.
Collapse
Affiliation(s)
- M Kaucikas
- Division of Molecular Biosciences, Imperial College London, South Kensington Campus, SW7 2AZ, UK
| | | | | |
Collapse
|
31
|
Schmidt FM, Vaittinen O, Metsälä M, Lehto M, Forsblom C, Groop PH, Halonen L. Ammonia in breath and emitted from skin. J Breath Res 2013; 7:017109. [PMID: 23445955 DOI: 10.1088/1752-7155/7/1/017109] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Ammonia concentrations in exhaled breath (eNH3) and skin gas of 20 healthy subjects were measured on-line with a commercial cavity ring-down spectrometer and compared to saliva pH and plasma ammonium ion (NH(+)4), urea and creatinine concentrations. Special attention was given to mouth, nose and skin sampling procedures and the accurate quantification of ammonia in humid gas samples. The obtained median concentrations were 688 parts per billion by volume (ppbv) for mouth-eNH3, 34 ppbv for nose-eNH3, and 21 ppbv for both mouth- and nose-eNH3 after an acidic mouth wash (MW). The median ammonia emission rate from the lower forearm was 0.3 ng cm(-2) min(-1). Statistically significant (p < 0.05) correlations between the breath, skin and plasma ammonia/ammonium concentrations were not found. However, mouth-eNH3 strongly (p < 0.001) correlated with saliva pH. This dependence was also observed in detailed measurements of the diurnal variation and the response of eNH3 to the acidic MW. It is concluded that eNH3 as such does not reflect plasma but saliva and airway mucus NH(+)4 concentrations and is affected by saliva and airway mucus pH. After normalization with saliva pH using the Henderson-Hasselbalch equation, mouth-eNH3 correlated with plasma NH(+)4, which points to saliva and plasma NH(+)4 being linked via hydrolysis of salivary urea.
Collapse
Affiliation(s)
- F M Schmidt
- Laboratory of Physical Chemistry, Department of Chemistry, University of Helsinki, Finland.
| | | | | | | | | | | | | |
Collapse
|
32
|
Yebo NA, Sree SP, Levrau E, Detavernier C, Hens Z, Martens JA, Baets R. Selective and reversible ammonia gas detection with nanoporous film functionalized silicon photonic micro-ring resonator. OPTICS EXPRESS 2012; 20:11855-62. [PMID: 22714172 DOI: 10.1364/oe.20.011855] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Portable, low cost and real-time gas sensors have a considerable potential in various biomedical and industrial applications. For such applications, nano-photonic gas sensors based on standard silicon fabrication technology offer attractive opportunities. Deposition of high surface area nano-porous coatings on silicon photonic sensors is a means to achieve selective, highly sensitive and multiplexed gas detection on an optical chip. Here we demonstrate selective and reversible ammonia gas detection with functionalized silicon-on-insulator optical micro-ring resonators. The micro-ring resonators are coated with acidic nano-porous aluminosilicate films for specific ammonia sensing, which results in a reversible response to NH(3)with selectivity relative to CO(2). The ammonia detection limit is estimated at about 5 ppm. The detectors reach a steady response to NH(3) within 30 and return to their base level within 60 to 90 seconds. The work opens perspectives on development of nano-photonic sensors for real-time, non-invasive, low cost and light weight biomedical and industrial sensing applications.
Collapse
Affiliation(s)
- Nebiyu A Yebo
- Ghent University-IMEC, Photonics Research group, INTEC, Sint-Pietersnieuwstraat 41, 9000 Gent, Belgium.
| | | | | | | | | | | | | |
Collapse
|
33
|
Abstract
Laser-spectrometric methods to derive absolute and traceable carbon monoxide (CO) amount fractions in exhaled human breath could be of advantage for early disease detection as well as for treatment monitoring. As proof-of-principle laboratory experiment, we employed intra-pulse and continuous wave (cw) quantum cascade laser spectroscopy (QCLAS), both at 4.6 μm. Additional experiments were carried out applying cw cavity ring-down spectroscopy (CRDS) with a CO sideband laser and a QCL. We emphasize metrological data quality objectives, thatis, traceability and uncertainty, which could serve as essential benefits to exhaled breath measurements. The results were evaluated and compared on a 100 μmol/mol CO level using the two QCLAS spectrometers, and the cw CO sideband laser CRDS setup. The relative standard uncertainties of the pulsed and the cw QCLAS CO amount fraction results were ±4.8 and ±2.8%, respectively, that from the CO sideband laser CRDS was ±2.7%. Sensitivities down to a 3 nmol/mol CO level were finally demonstrated and quantified by means of cw CRDS equipped with a QCL yielding standard uncertainties of about ±2.5 that are exclusively limited by the available line strength figure quality. With this study we demonstrate the achieved comparability of CO quantifications, adhering metrological principles.
Collapse
|
34
|
Arslanov DD, Swinkels K, Cristescu SM, Harren FJM. Real-time, subsecond, multicomponent breath analysis by Optical Parametric Oscillator based Off-Axis Integrated Cavity Output Spectroscopy. OPTICS EXPRESS 2011; 19:24078-24089. [PMID: 22109433 DOI: 10.1364/oe.19.024078] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Breath analysis is an attractive field of research, due to its high potential for non-invasive medical diagnostics. Among others, laser-based absorption spectroscopy is an excellent method for the detection of gases in exhaled breath, because it can combine a high sensitivity with a good selectivity, and a high temporal resolution. Here, we use a fast-scanning continuous wave, singly-resonant Optical Parametric Oscillator (wavelength range between 3 and 4 μm, linewidth 40 MHz, output power > 1 W, scanning speed 100 THz/s) with Off-Axis Integrated Cavity Output Spectroscopy for rapid and sensitive trace gas detection. Real-time, low- ppbv detection of ethane is demonstrated in exhaled human breath during free exhalations. Also, simultaneous, real-time multi-component gas detection of ethane, methane and water was performed in exhaled breath using a wide spectral coverage over 17 cm(-1) in 1 second. Furthermore, real-time detection of acetone, a molecule with a wide absorption spectrum, was shown in exhaled breath, with a sub-second time resolution (0.4 s).
Collapse
Affiliation(s)
- Denis D Arslanov
- Life Science Trace Gas Research Group, Molecular and Laser Physics, Institute for Molecules and Materials, Radboud University, P.O. Box 9010, NL-6500 GL Nijmegen, The Netherlands.
| | | | | | | |
Collapse
|
35
|
Medvedev IR, Neese CF, Plummer GM, De Lucia FC. Impact of atmospheric clutter on Doppler-limited gas sensors in the submillimeter/terahertz. APPLIED OPTICS 2011; 50:3028-3042. [PMID: 21691371 DOI: 10.1364/ao.50.003028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
It is well known that clutter (spectral interference) from atmospheric constituents can be a severe limit for spectroscopic point sensors, especially where high sensitivity and specificity are required. In this paper, we will show for submillimeter/terahertz (SMM/THz) sensors that use cw electronic techniques the clutter limit for the detection of common target gases with absolute specificity (probability of false alarm ≪ 10⁻¹⁰) is in the ppt (1 part in 10¹²) range or lower. This is because the most abundant atmospheric gases are either transparent to SMM/THz radiation (e.g., CO₂) or have spectra that are very sparse relative to the 10⁵ Doppler-limited resolution elements available (e.g., H₂O). Moreover, the low clutter limit demonstrated for cw electronic systems in the SMM/THz is independent of system size and complexity.
Collapse
Affiliation(s)
- Ivan R Medvedev
- Department of Physics, Wright State University, 3640 Colonel Glenn Highway, Dayton, Ohio 45435, USA
| | | | | | | |
Collapse
|
36
|
|
37
|
Manne J, Lim A, Jäger W, Tulip J. Off-axis cavity enhanced spectroscopy based on a pulsed quantum cascade laser for sensitive detection of ammonia and ethylene. APPLIED OPTICS 2010; 49:5302-5308. [PMID: 20885466 DOI: 10.1364/ao.49.005302] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A pulsed, distributed feedback (DFB) quantum cascade (QC) laser centered at 970 cm(-1) was used in combination with an off-axis cavity enhanced absorption (CEA) spectroscopic technique for the detection of ammonia and ethylene. Here, the laser is coupled into a high-finesse cavity with an optical path length of ∼76 m. The cavity is installed into a 53 cm long sample cell with a volume of 0.12 L. The laser is excited with short current pulses (5-10 ns), and the pulse amplitude is modulated with an external current ramp, resulting in a ∼0.3 cm(-1) frequency scan. A demodulation approach followed by numerical filtering was utilized to improve the signal-to-noise ratio. We demonstrated detection limits of ~15 ppb and ∼20 ppb for ammonia and ethylene, respectively, with less than 5 s averaging time.
Collapse
Affiliation(s)
- Jagadeeshwari Manne
- Electrical and Computer Engineering Department, University of Alberta, Edmonton, Alberta, Canada T6G 2V4.
| | | | | | | |
Collapse
|
38
|
Curl RF, Capasso F, Gmachl C, Kosterev AA, McManus B, Lewicki R, Pusharsky M, Wysocki G, Tittel FK. Quantum cascade lasers in chemical physics. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2009.12.073] [Citation(s) in RCA: 436] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
39
|
Rae SI, Khan I. Surface enhanced Raman spectroscopy (SERS) sensors for gas analysis. Analyst 2010; 135:1365-9. [DOI: 10.1039/b924537e] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
40
|
Wang C, Sahay P. Breath analysis using laser spectroscopic techniques: breath biomarkers, spectral fingerprints, and detection limits. SENSORS (BASEL, SWITZERLAND) 2009; 9:8230-62. [PMID: 22408503 PMCID: PMC3292105 DOI: 10.3390/s91008230] [Citation(s) in RCA: 209] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Revised: 10/09/2009] [Accepted: 10/10/2009] [Indexed: 12/27/2022]
Abstract
Breath analysis, a promising new field of medicine and medical instrumentation, potentially offers noninvasive, real-time, and point-of-care (POC) disease diagnostics and metabolic status monitoring. Numerous breath biomarkers have been detected and quantified so far by using the GC-MS technique. Recent advances in laser spectroscopic techniques and laser sources have driven breath analysis to new heights, moving from laboratory research to commercial reality. Laser spectroscopic detection techniques not only have high-sensitivity and high-selectivity, as equivalently offered by the MS-based techniques, but also have the advantageous features of near real-time response, low instrument costs, and POC function. Of the approximately 35 established breath biomarkers, such as acetone, ammonia, carbon dioxide, ethane, methane, and nitric oxide, 14 species in exhaled human breath have been analyzed by high-sensitivity laser spectroscopic techniques, namely, tunable diode laser absorption spectroscopy (TDLAS), cavity ringdown spectroscopy (CRDS), integrated cavity output spectroscopy (ICOS), cavity enhanced absorption spectroscopy (CEAS), cavity leak-out spectroscopy (CALOS), photoacoustic spectroscopy (PAS), quartz-enhanced photoacoustic spectroscopy (QEPAS), and optical frequency comb cavity-enhanced absorption spectroscopy (OFC-CEAS). Spectral fingerprints of the measured biomarkers span from the UV to the mid-IR spectral regions and the detection limits achieved by the laser techniques range from parts per million to parts per billion levels. Sensors using the laser spectroscopic techniques for a few breath biomarkers, e.g., carbon dioxide, nitric oxide, etc. are commercially available. This review presents an update on the latest developments in laser-based breath analysis.
Collapse
Affiliation(s)
- Chuji Wang
- Department of Physics and Astronomy and The Institute for Clean Energy Technology, Mississippi State University, Starkville, MS 39759, USA
| | - Peeyush Sahay
- Department of Physics and Astronomy and The Institute for Clean Energy Technology, Mississippi State University, Starkville, MS 39759, USA
| |
Collapse
|
41
|
Mashir A, Dweik RA. Exhaled breath analysis: The new interface between medicine and engineering. ADV POWDER TECHNOL 2009; 20:420-425. [PMID: 20948990 PMCID: PMC2952965 DOI: 10.1016/j.apt.2009.05.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Exhaled breath testing is becoming an increasingly important non-invasive diagnostic method that can be used in the evaluation of health and disease states in the lung and beyond. Potential advantages of breath tests over other conventional medical tests include their non-invasive nature, low cost, and safety. To advance in this area further, however, there has to be a close collaboration between technical experts and engineers who have devices looking for clinical application(s), the medical experts who have the clinical problems looking for a test/biomarker that can be helpful in diagnosis or monitoring, and industry/commercial experts who can build and commercialize the final product.
Collapse
Affiliation(s)
- Alquam Mashir
- Department of Pathobiology/Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, United States
| | - Raed A. Dweik
- Department of Pathobiology/Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, United States
- Department of Pulmonary and Critical Care Medicine/Respiratory Institute, Cleveland Clinic, Cleveland, OH 44195, United States
| |
Collapse
|
42
|
Bartlome R, Sigrist MW. Laser-based human breath analysis: D/H isotope ratio increase following heavy water intake. OPTICS LETTERS 2009; 34:866-868. [PMID: 19340153 DOI: 10.1364/ol.34.000866] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Following the ingestion of only 5.1 mL of D2O, a mid-infrared laser spectrometer determines the D/H isotope ratio increase in exhaled water vapor for the first time, to the best of our knowledge. This increase is still detectable several weeks after the heavy water intake. Collected breath samples are directly transferred into a high-temperature multipass cell operated at 373 K. No breath sample preparation is required. Aside from the capability to hinder unwanted condensation, measurements at elevated temperatures offer other advantages such as a lower temperature dependence of the delta value or the possibility to vary the intensity of absorption lines. We lay the foundation for many laser-based clinical applications. As an example, we measure a total body water weight of 55.2%+/-1.8% with respect to the total body weight, in agreement with the normal value of the male population.
Collapse
Affiliation(s)
- Richard Bartlome
- Institute for Quantum Electronics, ETH Zurich, Zurich, Switzerland
| | | |
Collapse
|
43
|
Langridge JM, Ball SM, Shillings AJL, Jones RL. A broadband absorption spectrometer using light emitting diodes for ultrasensitive, in situ trace gas detection. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:123110. [PMID: 19123548 DOI: 10.1063/1.3046282] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
A broadband absorption spectrometer has been developed for highly sensitive and target-selective in situ trace gas measurements. The instrument employs two distinct modes of operation: (i) broadband cavity enhanced absorption spectroscopy (BBCEAS) is used to quantify the concentration of gases in sample mixtures from their characteristic absorption features, and (ii) periodic measurements of the cavity mirrors' reflectivity are made using step-scan phase shift cavity ringdown spectroscopy (PSCRDS). The latter PSCRDS method provides a stand-alone alternative to the more usual method of determining mirror reflectivities by measuring BBCEAS absorption spectra for calibration samples of known composition. Moreover, the instrument's two modes of operation use light from the same light emitting diode transmitted through the cavity in the same optical alignment, hence minimizing the potential for systematic errors between mirror reflectivity determinations and concentration measurements. The ability of the instrument to quantify absorber concentrations is tested in instrument intercomparison exercises for NO(2) (versus a laser broadband cavity ringdown spectrometer) and for H(2)O (versus a commercial hygrometer). A method is also proposed for calculating effective absorption cross sections for fitting the differential structure in BBCEAS spectra due to strong, narrow absorption lines that are under-resolved and hence exhibit non-Beer-Lambert law behavior at the resolution of the BBCEAS measurements. This approach is tested on BBCEAS spectra of water vapor's 4v+delta absorption bands around 650 nm. The most immediate analytical application of the present instrument is in quantifying the concentration of reactive trace gases in the ambient atmosphere. The instrument's detection limits for NO(3) as a function of integration time are considered in detail using an Allan variance analysis. Experiments under laboratory conditions produce a 1sigma detection limit of 0.25 pptv for a 10 s acquisition time, which improves with further signal averaging to 0.09 pptv in 400 s. Finally, an example of the instrument's performance under field work conditions is presented, in this case of measurements of the sum of NO(3)+N(2)O(5) concentrations in the marine boundary layer acquired during the Reactive Halogens in the Marine Boundary Layer field campaign.
Collapse
Affiliation(s)
- Justin M Langridge
- Department of Chemistry, University Chemical Laboratory, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | | | | | | |
Collapse
|
44
|
Ohira SI, Toda K. Micro gas analyzers for environmental and medical applications. Anal Chim Acta 2008; 619:143-56. [DOI: 10.1016/j.aca.2008.05.010] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Revised: 05/04/2008] [Accepted: 05/06/2008] [Indexed: 10/22/2022]
|
45
|
Fukui Y, Yaegaki K, Murata T, Sato T, Tanaka T, Imai T, Kamoda T. Diurnal changes in oral malodour among dental-office workers. Int Dent J 2008; 58:159-66. [DOI: 10.1111/j.1875-595x.2008.tb00192.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
46
|
Patterson CS, McMillan LC, Stevenson K, Radhakrishnan K, Shiels PG, Padgett MJ, Skeldon KD. Dynamic study of oxidative stress in renal dialysis patients based on breath ethane measured by optical spectroscopy. J Breath Res 2007; 1:026005. [DOI: 10.1088/1752-7155/1/2/026005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
47
|
McCurdy MR, Bakhirkin Y, Wysocki G, Lewicki R, Tittel FK. Recent advances of laser-spectroscopy-based techniques for applications in breath analysis. J Breath Res 2007; 1:014001. [PMID: 21383427 DOI: 10.1088/1752-7155/1/1/014001] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|