Journal articles: 'UV-absorption detection'

1

Zhang, Peipei, and Shuyu Liu. "Solvent Effects on the UV Absorption Spectrum of Carmofur." Detection 04, no. 01 (2016): 25–31. http://dx.doi.org/10.4236/detection.2016.41004.

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Khan, Sulaiman, David Newport, and Stéphane Le Calvé. "Gas Detection Using Portable Deep-UV Absorption Spectrophotometry: A Review." Sensors 19, no. 23 (November 28, 2019): 5210. http://dx.doi.org/10.3390/s19235210.

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Several gas molecules of environmental and domestic significance exhibit a strong deep-UV absorption. Therefore, a sensitive and a selective gas detector based on this unique molecular property (i.e., absorption at a specific wavelength) can be developed using deep-UV absorption spectrophotometry. UV absorption spectrometry provides a highly sensitive, reliable, self-referenced, and selective approach for gas sensing. This review article addresses the recent progress in the application of deep-UV absorption for gas sensing owing to its inherent features and tremendous potentials. Applications, advancements, and challenges related to UV emission sources, gas cells, and UV photodetectors are assessed and compared. We present the relevant theoretical aspects and challenges associated with the development of portable sensitive spectrophotometer. Finally, the applications of UV absorption spectrometry for ozone, NO2, SO2, and aromatic organic compounds during the last decades are discussed and compared. A portable UV absorption spectrophotometer can be developed by using LEDs, hollow core waveguides (HCW), and UV photodetectors (i.e., photodiodes). LED provides a portable UV emission source with low power input, low-intensity drifts, low cost, and ease of alignment. It is a quasi-chromatic UV source and covers the absorption band of molecules without optical filters for absorbance measurement of a target analyte. HCWs can be applied as a miniature gas cell for guiding UV radiation for measurement of low gas concentrations. Photodiodes, on the other hand, offer a portable UV photodetector with excellent spectral selectivity with visible rejection, minimal dark current, linearity, and resistance against UV-aging.

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Xue, Yongjun, and Edward S. Yeung. "Laser-Based Ultraviolet Absorption Detection in Capillary Electrophoresis." Applied Spectroscopy 48, no. 4 (April 1994): 502–6. http://dx.doi.org/10.1366/000370294775268983.

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Laser-based UV absorption in capillary electrophoresis is demonstrated. The use of vacuum photodiodes and an all-electronic noise canceller provides adequate baseline stability despite the large inherent intensity noise in UV lasers. A 4-fold improvement in the detection limit is achieved in comparison to that of commercial instruments. The main advantage here is the better optical coupling with small capillary tubes, maximizing the available optical pathlength for absorption.

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Richter, P., K. S. de Boer, D. J. Bomans, A. Heithausen, and J. Koornneef. "Detection of H2 in UV Absorption in the LMC." Symposium - International Astronomical Union 190 (1999): 126–27. http://dx.doi.org/10.1017/s0074180900117607.

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Gauri, Samla, Zurina Zainal Abidin, Mohd Firdaus Kamuri, Mohd Adzir Mahdi, and Nurul Amziah Md Yunus. "Detection ofAeromonas hydrophilaUsing Fiber Optic Microchannel Sensor." Journal of Sensors 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/8365189.

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This research focuses on the detection ofAeromonas hydrophilausing fiber optic microchannel biosensor. Microchannel was fabricated by photolithography method. The fiber optic was chosen as signal transmitting medium and light absorption characteristic of different microorganisms was investigated for possible detection. Experimental results showed thatAeromonas hydrophilacan be detected at the region of UV-Vis spectra between 352 nm and 354 nm which was comparable to measurement provided by UV spectrophotometer and also theoretical calculation by Beer-Lambert Absorption Law. The entire detection can be done in less than 10 minutes using a total volume of 3 μL only.This result promises good potential of this fiber optic microchannel sensor as a reliable, portable, and disposable sensor.

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Li, Yalong, Xiaoxing Zhang, Xin Li, Zhaolun Cui, and Hai Xiao. "Detection of Ozone and Nitric Oxide in Decomposition Products of Air-Insulated Switchgear Using Ultraviolet Differential Optical Absorption Spectroscopy (UV-DOAS)." Applied Spectroscopy 72, no. 8 (May 4, 2018): 1244–51. http://dx.doi.org/10.1177/0003702818773091.

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Air-insulated switchgear cabinets play a role in the protection and control of the modern power grid, and partial discharge (PD) switchgear is a long-term process in the non-normal operation of one of the situations; thus, condition monitoring of the switchgear is important. The air-insulated switchgear during PD enables the decomposition of air components, namely, O3 and NO. A set of experimental platforms was designed on the basis of the principle of ultraviolet differential optical absorption spectroscopy (UV-DOAS) to detect O3 and NO concentrations in air-insulated switchgear. Differential absorption algorithm and wavelet transform were used to extract effective absorption spectra; a linear relationship between O3 and NO concentrations and absorption spectrum data were established. O3 detection linearity was up to 0.9992 and the detection limit was at 3.76 ppm. NO detection linearity was up to 0.9990 and the detection limit was at 0.64 ppm. Results indicate that detection platform is suitable for detecting trace O3 and NO gases produced by PD of the air-insulated switchgear.

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Rewick, Robert T., Mary L. Schumacher, and Daniel L. Haynes. "The UV Absorption Spectra of Chemical Agents and Simulants." Applied Spectroscopy 40, no. 2 (February 1986): 152–56. http://dx.doi.org/10.1366/0003702864509493.

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The uv spectra of chemical agents GA, GB, GD, VX, HD, and L and common agent simulants have been measured in cyclohexane solution from 350 to 200 nm. The purity of the agents, measured by gas chromatographic analysis, was in general >96%. At 230 nm, the strength of the uv absorption followed the general trend L > VX > GA > HD > GD > GB > DMMP. Except for HD and L, agent spectra lacked characteristic features that will be useful for remote detection by uv sensors.

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Zhang, Yu, Hong Yu, and Miaoyu Wang. "Determination of pyrrolidinium ionic liquid cations by ion chromatography-indirect ultraviolet detection with imidazolium ionic liquids as both an ultraviolet absorption reagent and an eluting agent." Analytical Methods 7, no. 13 (2015): 5654–60. http://dx.doi.org/10.1039/c5ay01211b.

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Hemida, Mohamed, Lewellwyn Joseph Coates, Shing Lam, Vipul Gupta, Mirek Macka, Hans-Jürgen Wirth, Andrew A. Gooley, Paul R. Haddad, and Brett Paull. "Miniature Multiwavelength Deep UV-LED-Based Absorption Detection System for Capillary LC." Analytical Chemistry 92, no. 20 (September 28, 2020): 13688–93. http://dx.doi.org/10.1021/acs.analchem.0c03460.

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Enami, T., and N. Nagae. "UV absorption detection with a packed flow cell in microcolumn liquid chromatography." Analusis 26, no. 5 (June 1998): 31–32. http://dx.doi.org/10.1051/analusis:199826050031.

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11

Robin, Kristelle, Jean-Luc Reverchon, Laurent Mugherli, Michel Fromant, Pierre Plateau, and Henri Benisty. "Detection of biological macromolecules on a biochip dedicated to UV specific absorption." Biosensors and Bioelectronics 24, no. 6 (February 2009): 1585–91. http://dx.doi.org/10.1016/j.bios.2008.08.028.

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Arnold, Bradley R., Christopher E. Cooper, Michael R. Matrona, Darren K. Emge, and Jeffrey B. Oleske. "Stand-off deep-UV Raman spectroscopy." Canadian Journal of Chemistry 96, no. 7 (July 2018): 614–20. http://dx.doi.org/10.1139/cjc-2017-0678.

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UV Raman spectra were measured using a novel experimental configuration. This configuration allows many of the difficulties associated with UV excitation and high-power pulsed laser sources to be mitigated. Large sample areas are imaged into the detection system allowing high power excitation sources to be used while simultaneously avoiding sample degradation and multi-photon absorption effects. Such large detection areas allow large numbers of molecular scatters to be probed even with minimal penetration depth. Alignment issues between sample and collection optics are also simplified. Several common solvents were studied using 213 nm light and their spectra reported.

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Zrimsek, Alyssa B., Sergei V. Bykov, and Sanford A. Asher. "Deep Ultraviolet Standoff Photoacoustic Spectroscopy of Trace Explosives." Applied Spectroscopy 73, no. 6 (August 10, 2018): 601–9. http://dx.doi.org/10.1177/0003702818792289.

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We demonstrate deep ultraviolet (UV) photoacoustic spectroscopy (PAS) of trace explosives using a sensitive microphone at meter standoff distances. We directly detect 10 µg/cm2 of pentaerythritol tetranitrate (PETN), 2,4,6-trinitrotoluene (TNT), and ammonium nitrate (AN) with 1 s accumulations from a 3 m standoff distance. Large PAS signals for standoff detection are achieved by exciting into the absorption bands of the explosives with a 213 nm laser. We also investigate the impact of the deep UV photochemistry of AN on the PAS signal strength and stability. We find that production of gaseous species during photolysis of AN enhances the PAS signal strength. This deep UV photochemistry can, however, limit the PAS signal lifetimes when detecting trace quantities.

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Gao, Zhi-hao, Zheng-zhong Lin, Xiao-mei Chen, Hui-ping Zhong, and Zhi-yong Huang. "A fluorescent probe based on N-doped carbon dots for highly sensitive detection of Hg2+ in aqueous solutions." Analytical Methods 8, no. 10 (2016): 2297–304. http://dx.doi.org/10.1039/c5ay03088a.

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15

Tian, Weiguo, Yinan Xue, Jintao Tian, Peizhen Gong, Jinhui Dai, Xin Wang, and Zhibin Zhu. "Colorimetric and fluorometric dual-mode detection of aniline pollutants based on spiropyran derivatives." RSC Advances 6, no. 86 (2016): 83312–20. http://dx.doi.org/10.1039/c6ra17862f.

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The selective UV-vis absorption of spiropyran and the fluorescence quenching of SP-cellulose material induced by aniline were observed and exploited for rapid detection and accurate quantitative determination of aniline pollutants in the environment.

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16

Christesen, Steven D., Jay Pendell Jones, Joseph M. Lochner, and Aaron M. Hyre. "Ultraviolet Raman Spectra and Cross-Sections of the G-series Nerve Agents." Applied Spectroscopy 62, no. 10 (October 2008): 1078–83. http://dx.doi.org/10.1366/000370208786049024.

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Ultraviolet (UV) Raman spectroscopy is being applied to the detection of chemical agent contamination of natural and man-made surfaces. In support of these efforts, we have measured the UV Raman signatures of the G-series nerve agents GA (tabun), GB (sarin), GD (soman), GF (cyclosarin), and the agent simulant diisopropyl methylphosphonate (DIMP) at 248 nm and 262 nm, as well as taking their UV Raman and UV absorption cross-sections. Of these chemicals, only GA exhibits any significant pre-resonance enhancement. We also show that reduction of the excitation wavelength from 262 nm to 248 nm effectively shifts the Raman spectrum away from a substantial sample fluorescence background, implying a significant improvement in detection capability.

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Sun, Shichao, Qinghai Shu, Pengchao Lin, Yanyue Li, Shaohua Jin, Xin Chen, and Dequan Wang. "Triphenylamine based lab-on-a-molecule for the highly selective and sensitive detection of Zn2+ and CN− in aqueous solution." RSC Advances 6, no. 96 (2016): 93826–31. http://dx.doi.org/10.1039/c6ra17354c.

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A triphenylamine based lab-on-a-molecule TATP was designed and synthesized as a bifunctional sensor for the detection of Zn²⁺ and CN⁻ through fluorescence and UV-Vis absorption channels, with detection limits of 14 nM and 0.37 μM, respectively.

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Rydosz, Artur, Kamil Staszek, Andrzej Brudnik, and Slawomir Gruszczynski. "Tin Dioxide Thin Film with UV-enhanced Acetone Detection in Microwave Frequency Range." Micromachines 10, no. 9 (August 30, 2019): 574. http://dx.doi.org/10.3390/mi10090574.

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In this paper, the UV illumination effect for microwave gas sensors based on the tin dioxide was verified. A UV LED with emission wavelength close to the absorption edge of the SnO2 gas-sensing layer was selected as the UV source. The developed gas sensors were tested under exposure to acetone in the 0–200 ppm range at room temperature. The sensor’s complex reflection coefficient corresponding to target gas concentration was measured with the use of a five-port reflectometer system exhibiting enhanced uncertainty distribution, which allows for the detection of low gas concentration. The UV illumination significantly emphasizes the sensors’ response in terms of both magnitude and phase for low gas concentrations, in contrast to previously reported results, in which only the reflection coefficient’s phase was affected. The highest responses were obtained for modulated UV illumination.

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19

El-Yazbi, Amira F., and Glen R. Loppnow. "A selective, inexpensive probe for UV-induced damage in nucleic acids." Canadian Journal of Chemistry 91, no. 5 (May 2013): 320–25. http://dx.doi.org/10.1139/cjc-2012-0417.

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Absorption of UV light by nucleic acids can result in the formation of molecular lesions in DNA and RNA, leading to mutagenesis, carcinogenesis, and cell death. In this work, hairpin oligonucleotide probes, which have previously been shown to be selective for DNA damage, are used. The hypochromic effect, which arises from the formation of the target–hairpin hybrid when there is no damage, is used to measure the amount of UV damage by measuring the amount of single-stranded DNA oligonucleotides. With accumulated UV exposure, the target–hairpin hybrid concentration decreases and the absorbance increases, enabling detection of UV-induced DNA damage. Our results show that the selectivity for DNA damage of the hypochromism probe is comparable with the molecular beacon probes, detecting between one and three lesions in an oligonucleotide. In addition, this probe is more than 10 times cheaper than molecular beacon probes. However, it shows lower sensitivity to DNA damage. This makes its use recommended for high-throughput, qualitative analysis of DNA damage. This introduces a simple, fast, mix-and-read assay for the detection of DNA damage.

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20

Stålberg, O., D. Westerlund, U.-K. Hultin, and S. Schmidt. "Improvements in drug purity determination by capillary electrophoresis using UV-absorption and LIF-detection with a UV-laser." Chromatographia 44, no. 7-8 (April 1997): 355–61. http://dx.doi.org/10.1007/bf02466310.

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21

Bobe, Sharad R., Aaron Michael Raynor, Sheshanath V. Bhosale, and Sidhanath V. Bhosale. "Detection of Trace Amounts of Water in Organic Solvent by 8-Hydroxypyrene-1,3,6-Trisulfonic Acid Trisodium Salt." Australian Journal of Chemistry 67, no. 4 (2014): 615. http://dx.doi.org/10.1071/ch13381.

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A colorimetric and fluorescent sensor was developed based on 8-hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt (HPTS) for the detection of trace amounts of water in polar organic solvents. Fluorescence and UV-visible absorption spectra of HPTS were measured in a variety of organic solvents (DMF, DMSO, ethanol, methanol). Fluorescence maxima comparable with maximum/minimum ratios were determined by using UV-visible absorption spectroscopy. The HPTS sensor exhibits high sensitivity for water with a detection limit as low as 0.0001 to 0.0005 wt-%. In addition, naked-eye inspection of solutions of HPTS sensor in organic solvents before and after addition of water showed dramatic changes in colour from blue to green. These findings can be applied in the use of HPTS as a molecular probe for trace amounts of water in organic solvents.

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Esposito, F., M. R. Calvello, E. Gueguen, and G. Pavese. "A new algorithm for brown and black carbon identification and organic carbon detection in fine atmospheric aerosols by a multi-wavelength Aethalometer." Atmospheric Measurement Techniques Discussions 5, no. 1 (February 1, 2012): 1003–27. http://dx.doi.org/10.5194/amtd-5-1003-2012.

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Abstract. A novel approach for the analysis of aerosol absorption coefficient measurements is presented. A 7-wavelenghts aethalometer has been employed to identify brown carbon (BrC) and black carbon (BC) and to detect organic carbon (OC) in fine atmospheric aerosols (PM2.5). The Magee Aethalometer estimates the BC content in atmospheric particulate by measuring the light attenuation in the aerosols accumulated on a quartz filter, at the standard wavelength λ = 0.88 μm. The known Magee algorithm is based on the hypothesis of a mass absorption coefficient inversely proportional to the wavelength. The new algorithm has been developed and applied to the whole spectral range; it verifies the spectral absorption behavior and, thus, it distinguishes between black and brown carbon. Moreover, it allows also to correct the absorption estimation at the UV wavelength commonly used to qualitatively detect the presence of mixed hydrocarbons. The algorithm has been applied to data collected in Agri Valley, located in Southern Italy, where torched crude oil undergoes a pre-treatment process. The Magee Aethalometer has been set to measure Aerosol absorption coefficients τaer (λ, t) every 5 min. Wavelength dependence of τaer (λ, t) has been analyzed by a best-fit technique and, excluding UV-wavelengths, both the absorption Angstrom coefficient α and the BC (or BrC) concentration have been determined. Finally, daily histograms of α provide information on optical properties of carbonaceous aerosol, while the extrapolation at UV-wavelengths gives information on the presence of semivolatile organic carbon (OC) particles.

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Zhang, Zhaojun, Wei Zheng, Richeng Lin, and Feng Huang. "High-sensitive and fast response to 255 nm deep-UV light of CH 3 NH 3 PbX 3 (X = Cl, Br, I) bulk crystals." Royal Society Open Science 5, no. 9 (September 2018): 180905. http://dx.doi.org/10.1098/rsos.180905.

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Deep-UV light detection has important application in surveillance and homeland security regions. CH 3 NH 3 PbX 3 (X = Cl, Br, I) materials have outstanding optical absorption and electronic transport properties suitable for obtaining excellent deep-UV photoresponse. In this work, we have grown high-quality CH 3 NH 3 PbX 3 (X = Cl, Br, I) bulk crystals and used them to fabricate photodetectors. We found that they all have high-sensitive and fast-speed response to 255 nm deep-UV light. Their responsivities are 10–10 3 times higher than MgZnO and Ga 2 O 3 detectors, and their response speeds are 10 3 times faster than Ga 2 O 3 and ZnO detectors. These results indicate a new promising route for deep-UV detection.

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Nissen, Mona, Brenda Doherty, Jonas Hamperl, Jens Kobelke, Karina Weber, Thomas Henkel, and Markus Schmidt. "UV Absorption Spectroscopy in Water-Filled Antiresonant Hollow Core Fibers for Pharmaceutical Detection." Sensors 18, no. 2 (February 6, 2018): 478. http://dx.doi.org/10.3390/s18020478.

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Bechtel, Kate L., Richard N. Zare, Alexander A. Kachanov, Steve S. Sanders, and Barbara A. Paldus. "Moving beyond Traditional UV−Visible Absorption Detection: Cavity Ring-Down Spectroscopy for HPLC." Analytical Chemistry 77, no. 4 (February 2005): 1177–82. http://dx.doi.org/10.1021/ac048444r.

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Sharma, Sonika, H. Dennis Tolley, Paul B. Farnsworth, and Milton L. Lee. "LED-Based UV Absorption Detector with Low Detection Limits for Capillary Liquid Chromatography." Analytical Chemistry 87, no. 2 (December 24, 2014): 1381–86. http://dx.doi.org/10.1021/ac504275m.

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Zhang, Xiaoxing, Zhaolun Cui, Zheng Cheng, Yalong Li, and Hai Xiao. "Quantitative detection of H2S and CS2 mixed gases based on UV absorption spectrometry." RSC Advances 7, no. 80 (2017): 50889–98. http://dx.doi.org/10.1039/c7ra09983e.

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Kikuchi, Koichi, Nobuo Nakahara, Masahiro Honda, Shinzo Suzuki, Kazuya Saito, Haruo Shiromaru, Kotaro Yamauchi, et al. "Separation, Detection, and UV/Visible Absorption Spectra of Fullerenes; C76, C78, and C84." Chemistry Letters 20, no. 9 (September 1991): 1607–10. http://dx.doi.org/10.1246/cl.1991.1607.

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29

Zhou, Kun-peng, Wei-hong Bi, Qi-hang Zhang, Xing-hu Fu, and Guo-qing Wu. "Influence of temperature and turbidity on water COD detection by UV absorption spectroscopy." Optoelectronics Letters 12, no. 6 (November 2016): 461–64. http://dx.doi.org/10.1007/s11801-016-6178-z.

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30

Vilas, Faith, and Amanda R. Hendrix. "Space Weathering of S-Complex Asteroids Manifested in the UV/Blue: Recent Insights and Future Directions." Proceedings of the International Astronomical Union 10, S318 (August 2015): 201–5. http://dx.doi.org/10.1017/s1743921315009722.

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AbstractSpace weathering affects reflectance spectra of the Moon and S-complex asteroids by spectral bluing (increasing reflectance with decreasing wavelength) of their surface materials at UV/blue (less than 400 nm) wavelengths. This spectral bluing is attributed to a degradation of the UV absorption feature seen in spectral reflectance of olivine as a result of the creation of nanophase (npFe0) iron. We have modeled the effect of the addition of small amounts of npFe0 intimately mixed with particles from a hypothetical material and a terrestrial basalt. The addition of 0.0001% npFe0 affects the reflectance at these UV/blue wavelengths, while the addition of 0.01% is required to see the visible/near infrared reddening and diminution of VNIR absorption features. Thus, the UV/blue spectral reflectance characteristics allow earlier detection of the onset of space weathering effects.

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Zhong, Xiu-Di, Dong-Sai Fu, Ping-Ping Wu, Qian Liu, Guo-Chun Lin, Shuo-Hui Cao, and Yao-Qun Li. "Rapid fluorescence spectroscopic screening method for the sensitive detection of thiabendazole in red wine." Anal. Methods 6, no. 18 (2014): 7260–67. http://dx.doi.org/10.1039/c4ay00991f.

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This method (d) has the advantage of improving spectral resolution and measurement sensitivity, as well as eliminating the interference of spectral background from red wine, compared with UV-Vis absorption spectroscopy (a) and conventional fluorescence spectroscopy (b).

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Li, Ruru, Xiaoyu Huang, Guolin Lu, and Chun Feng. "A fluorescence and UV/vis absorption dual-signaling probe with aggregation-induced emission characteristics for specific detection of cysteine." RSC Advances 8, no. 43 (2018): 24346–54. http://dx.doi.org/10.1039/c8ra03756f.

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A dual-signaling of fluorescence and UV/vis absorption modes for selective and quantitative detection of cysteine over homocysteine, N-acetyl-l-cysteine and glutathione is developed on the basis of aggregation-induced emission (AIE) effect.

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WADA, SHUJI, TOMOKI KAWATSU, YUYA HASHIZUME, TOMOKI YABUTANI, and JUNKO MOTONAKA. "A LONG PATHLENGTH SPECTROPHOTOMETRIC TEGAFUR DETECTOR USING A LIQUID-CORE WAVEGUIDE." International Journal of Modern Physics B 20, no. 25n27 (October 30, 2006): 4046–50. http://dx.doi.org/10.1142/s0217979206040830.

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A Liquid-Core Waveguide (LCW) detection system for high sensitive determination of tegaful (FT) was developed. In this system the LCW cell was connected to the end of a hollow cathode lump and the other end to a UV spectrometer. A sample solution containing FT was pumped to the LCW cell through a T-shaped connector. A UV absorption of analyte was detected by the UV spectrometer. The configuration of connectors of LCW cell to the light source and the UV detector was designed. Stable and high responses of FT were obtained in a double tube system in which an edge of LCW cell was covered with another tube with large diameter was set in the T-connector. It was found that the UV absorption response of FT obtained in this LCW system depends on the core length and the concentration of FT. The sensitivity of FT obtained by using 65 cm of the LCW cell length was 10-fold higher than that of using 1 cm cell which was often used with a conventional UV-visible detector.

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Zhang, Yin, Xiaoxing Zhang, Chang Liu, Yi Li, Zhaolun Cui, and Mingli Fu. "Ultraviolet Spectral Analysis and Quantitative Detection of Heptafluoroisobutyronitrile (C4F7N) in a C4F7N–Carbon Dioxide (CO2) Gas Mixture." Applied Spectroscopy 73, no. 8 (March 8, 2019): 917–26. http://dx.doi.org/10.1177/0003702819833702.

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As an alternative to sulfur hexafluoride (SF6) with great potential for application, heptafluoroisobutyronitrile–carbon dioxide (C4F7N–CO2) gas mixture has been applied in various gas-insulated equipment. The insulation performance of the gas mixture is closely related to the mixing ratio. Therefore, accurate quantification of C4F7N in the C4F7N–CO2 gas mixture has very important engineering significance. At present, there are few reports on the rapid quantitative detection of the concentration of C4F7N in the gas mixture. In this paper, a rapid analytical method for C4F7N concentration based on ultraviolet (UV) absorption spectroscopy is constructed. The UV spectral characteristics of C4F7N molecules are calculated by density functional theory. The appropriate bands that can be detected are determined by analyzing the calculated results. A concentration detection system of C4F7N based on UV absorption spectroscopy is built. Through analysis of the calculated results and experimental results, a quantitative detection method of C4F7N in the C4F7N/CO2 gas mixture is determined. The method can achieve accurate detection of the concentration of the gas mixture in the conventional application range (including 4–10% C4F7N). The coefficient of the determination R2 of the concentration inversion curve reaches 0.999 and the inversion error ratio does not exceed 5%. The related research results provide an important reference for the engineering application of the gas mixture.

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Khan, Sulaiman, David Newport, and Stéphane Le Calvé. "Development of a Toluene Detector Based on Deep UV Absorption Spectrophotometry Using Glass and Aluminum Capillary Tube Gas Cells with a LED Source." Micromachines 10, no. 3 (March 18, 2019): 193. http://dx.doi.org/10.3390/mi10030193.

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A simple deep-ultraviolet (UV) absorption spectrophotometer based on ultraviolet light-emitting diode (UV LED) was developed for the detection of air-borne toluene with a good sensitivity. A fiber-coupled deep UV-LED was employed as a light source, and a spectrometer was used as a detector with a gas cell in between. 3D printed opto-fluidics connectors were designed to integrate the gas flow with UV light. Two types of hollow core waveguides (HCW) were tested as gas cells: a glass capillary tube with aluminum-coated inner walls and an aluminum capillary tube. The setup was tested for different toluene concentrations (10–100 ppm), and a linear relationship was observed with sensitivities of 0.20 mA·U/ppm and 0.32 mA·U/ppm for the glass and aluminum HCWs, respectively. The corresponding limits of detection were found to be 8.1 ppm and 12.4 ppm, respectively.

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Shi, Qing, Ling-Yi Shen, Hong Xu, Zhi-Yong Wang, Xian-Jiong Yang, Ya-Li Huang, Carl Redshaw, and Qi-Long Zhang. "A 1-Hydroxy-2,4-Diformylnaphthalene-Based Fluorescent Probe and Its Detection of Sulfites/Bisulfite." Molecules 26, no. 11 (May 21, 2021): 3064. http://dx.doi.org/10.3390/molecules26113064.

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A novel 1-hydroxy-2,4-diformylnaphthalene-based fluorescent probe L was synthesized by a Knoevenagel reaction and exhibited excellent sensitivity and selectivity towards sulfite ions (SO32−) and bisulfite ions (HSO3−). The detection limits of the probe L were 0.24 μM using UV-Vis spectroscopy and 9.93 nM using fluorescence spectroscopy, respectively. Furthermore, the fluorescent probe L could be utilized for detection in real water samples with satisfactory recoveries in the range 99.20%~104.30% in lake water and 100.00%~104.80% in tap water by UV-Vis absorption spectrometry, and in the range 100.50%~108.60% in lake water and 102.70%~103.80% in tap water by fluorescence spectrophotometry.

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Takeuchi, Toyohide, Anang Sedyohutomo, and Lee Wah Lim. "DETERMINATION OF CYCLODEXTRINS BY CAPILLARY LIQUID CHROMATOGRAPHY WITH INDIRECT CONDUCTIMETRIC DETECTION." Jurnal Riset Kimia 4, no. 1 (February 11, 2015): 89. http://dx.doi.org/10.25077/jrk.v4i1.112.

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ABSTRACT Cyclodextrins (CDs) contained in a bottled Japanese tea and a wasabi (Japanese horseradish) paste were determined by capillary liquid chromatography (LC) with indirect conductimetric detection based on dilution of the mobile phase due to the analytes. High electrical conductivity background was maintained by addition of 5 mM sodium nitrate in the mobile phase, and the analytes were visualized by decreases in the background when they eluted. The dynamic reserve, defined as the ratio of the background to its noise level, achieved under the present conditions was 1.7×105, which was much larger than that achieved by UV absorption detection. This means that indirect conductimetric detection gave better sensitivity than indirect UV absorption detection. A capacitively coupled contactless conductivity detector was convenient to monitor the effluents from capillary columns with minimum extra-column band broadening. The signals as negative peaks were linear to the concentration of the analytes, and the concentration detection limits achieved at S/N=3 were 0.02, 0.05 and 0.02% (w/v) for α-, β- and γ-CD, respectively, corresponding to the mass detection limits of 30-75 ng for 0.15 μL injection. The present detection method is not selective but universal, and it is useful in capillary LC when analytes have neither chromophore nor fluorophore groups. Keywords: Capillary liquid chromatography, Indirect conductimetric detection, Capacitively coupled contactless conductivity detector, Cyclodextrins

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Arachchige, Hashitha M. M. Munasinghe, Nanda Gunawardhana, Dario Zappa, and Elisabetta Comini. "UV Light Assisted NO2Sensing by SnO2/Graphene Oxide Composite." Proceedings 2, no. 13 (November 23, 2018): 787. http://dx.doi.org/10.3390/proceedings2130787.

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Nitric oxide (NO2) is one of the air pollutants that pose serious environmental concerns over the years. In this study, SnO2 nanowires were synthesized by evaporation-condensation method and graphene oxide were synthesized using modified Hummers method for low temperature NO2 detection. Drop cast method was used to transfer graphene oxide (GO), to form composite GO-metal oxide p-n junctions. With integration of reduce graphene oxide (rGO), the UV light absorption was enhanced. This metal oxide composite has shown a reversible response in detecting low concentrations of NO2 under UV irradiation, with a working temperature range of 50–150 °C. Pure SnO2 shows 20% response to NO2 (4 ppm) in dark conditions, while the response increasesupto60%usingUVirradiationat50°C.Furthermore, SnO2/rGOshowsa40%ofresponse in dark, while the response increases to 160% under UV light illumination. This composite exhibits excellent recovery and maintains the baseline under UV light at low temperatures, which effectively overcome the drawbacks of low recovery typically shown by metal oxide gas sensors at low temperature.

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Khan, Sulaiman, David Newport, and Stéphane Le Calvé. "Low-volume PEEK gas cell for BTEX detection using portable deep-UV absorption spectrophotometry." Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 243 (December 2020): 118727. http://dx.doi.org/10.1016/j.saa.2020.118727.

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Mao, Qinglu, and Janusz Pawliszyn. "Demonstration of isoelectric focusing on an etched quartz chip with UV absorption imaging detection†." Analyst 124, no. 5 (1999): 637–41. http://dx.doi.org/10.1039/a809756i.

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Fritz, B., V. Handwerk, M. Preidel, and R. Zellner. "Direct Detection of Hydroxy-Cyclohexadienyl in the Gas Phase by cw-UV-Laser Absorption." Berichte der Bunsengesellschaft für physikalische Chemie 89, no. 3 (March 1985): 343–44. http://dx.doi.org/10.1002/bbpc.19850890347.

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He, Yan, and Edward S. Yeung. "High-throughput screening of kinase inhibitors by multiplex capillary electrophoresis with UV absorption detection." ELECTROPHORESIS 24, no. 12 (January 2003): 101–8. http://dx.doi.org/10.1002/elps.200390000.

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Gavenda, Aleš, Juraj Ševčík, Jitka Psotová, Petr Bednář, Petr Barták, Pavel Adamovský, and Vilím Šimánek. "Determination of anthracycline antibiotics doxorubicin and daunorubicin by capillary electrophoresis with UV absorption detection." ELECTROPHORESIS 22, no. 13 (August 2001): 2782–85. http://dx.doi.org/10.1002/1522-2683(200108)22:13<2782::aid-elps2782>3.0.co;2-i.

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Hassan, N. K., and M. R. Hashim. "Flake-like ZnO nanostructures density for improved absorption using electrochemical deposition in UV detection." Journal of Alloys and Compounds 577 (November 2013): 491–97. http://dx.doi.org/10.1016/j.jallcom.2013.06.010.

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Sanz, Jesus, Felix Gallarta, Javier Galban, and Juan R. Castillo. "Antimony determination by hydride generation — UV-visible molecular absorption spectrophotometry with diode-array detection." Fresenius' Zeitschrift für analytische Chemie 330, no. 6 (January 1988): 510–15. http://dx.doi.org/10.1007/bf00490759.

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Kato, Tatsuhisa. "Absorption and Emission Spectra for C60 Anions." Laser Chemistry 14, no. 1-3 (January 1, 1994): 155–60. http://dx.doi.org/10.1155/1994/29769.

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Absorption spectra are detected for C60− and C602− produced electrolytically in solution at room temperature. Theoretical analysis of the spectrum of C60− by CNDO/S calculations gives an interpretation of the characteristic near-IR bands, the weak visible bands, and the strong bands in the UV region. The emission spectrum of C60− is a mirror image of the near-IR absorption band, and the detection of the emission reconfirms our original assignment of the absorption spectrum. The nature of the spectrum of C602− is characterized by a similar orbital picture to that of C60−. Further laser experiments of significance are proposed.

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Morrison, Sean, Matthew M. Pieri, David Syphers, and Tae-Sun Kim. "Probing inhomogeneity in the helium ionizing UV background." Monthly Notices of the Royal Astronomical Society 489, no. 1 (August 19, 2019): 868–80. http://dx.doi.org/10.1093/mnras/stz2187.

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ABSTRACT We present an analysis combining the simultaneous measurement of intergalactic absorption by hydrogen (${\rm {H\,\small {I}}}$), helium (${\rm {He\,\small {II}}}$), and oxygen (${\rm {O\,\small {VI}}}$) in UV and optical quasar spectra. The combination of the ${\rm {H\,\small {I}}}$ and ${\rm {He\,\small {II}}}$ Lyman-alpha forests through η (the ratio of column densities of singly ionized helium to neutral hydrogen) is thought to be sensitive to large-scale inhomogeneities in the extragalactic UV background. We test this assertion by measuring associated five-times-ionized oxygen (${\rm {O\,\small {VI}}}$) absorption, which is also sensitive to the UV background. We apply the pixel optical depth technique to ${\rm {O\,\small {VI}}}$ absorption in high and low η samples filtered on various scales. This filtering scale is intended to represent the scale of any coherent oxygen excess/deficit. We find a 2σ detection of an ${\rm {O\,\small {VI}}}$ opacity excess in the low η sample on scales of ∼10 cMpc for HE 2347-4342 at $\bar{z}\approx 2.6$, consistent with a large-scale excess in hard UV photons. However, for HS 1700 + 6416 at $\bar{z}\approx 2.5$ we find that the measured ${\rm {O\,\small {VI}}}$ absorption is not sensitive to differences in η. HS 1700 + 6416 also shows a relative absence of ${\rm {O\,\small {VI}}}$ overall, which is 6σ inconsistent with that of HE 2347-4342. This implies UV background inhomogeneities on ≳200 cMpc scales, hard UV regions having internal ionization structure on ∼10 cMpc scales, and soft UV regions showing no such structure. Furthermore, we perform the pixel optical depth search for oxygen on the ${\rm {He\,\small {II}}}$ Gunn-Peterson trough of HE 2347-4342 and find results consistent with post-${\rm {He\,\small {II}}}$-reionization conditions.

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Brayan, J. G., D. J. Malcolme-Lawes, C. D. Mew, and S. Xie. "A Hadamard transform UV absorption detection for high performance liquid chromatography. Part I. Preliminary experiments." Journal of Automatic Chemistry 17, no. 2 (1995): 77–82. http://dx.doi.org/10.1155/s1463924695000137.

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The principles and design of a Hadamard transform UV absorbance detector for liquid chromatography are outlined, and some spectra of aromatic compounds passing through its flow cell are presented. This approach could be valuable in providing a low-cost multi-wavelength detection method for liquid chromatography.

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Aura, Rusu, Imre Silvia, Mircia Eleonora, and Hancu Gabriel. "Quinolone Antibacterials: Commentary and Considerations Regarding UV Spectra and Chemical Structure." Acta Medica Marisiensis 61, no. 4 (December 1, 2015): 328–36. http://dx.doi.org/10.1515/amma-2015-0084.

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AbstractObjective: Antibacterial quinolones represent an important class of pharmaceutical compounds that are widely used in therapy. Analytical methods that rely on their property to absorb light in the UV range are commonly used for their analysis. In the current study we present an interpretation of the relationship between chemical structure – UV spectra based on the comparative examination of UV spectral behavior of the eighteen quinolone derivatives and four model compounds.Methods: Eighteen quinolone derivatives and four model compounds were selected and their UV spectra were recorded in different solvents (methanol, 0.1M HCl, 0.1M NaOH).Results: The studied compounds show three absorption maximum values located around 210-230 nm, 270-300 nm and 315-330 nm values. A general characteristic was observed as the absorption bands exhibited both hypsochrome and bathochrome shifts, by comparison in different solvents. Most commonly we observed a slight hypsochrome shift at acidic pH (protonated form prevails) and basic pH (anionic form prevails). The structural differences are reflected in changes of UV spectra only when there are auxochrom substituents or different basic substituents are present in the quinolones structure.Conclusions: The correlations between the chemical structure of quinolone derivatives and their UV spectra using model compounds were established. This study provides useful information that can be used successfully in various UV spectrophotometric analysis methods or in more complex analytical methods using UV detection, and also in pharmacodynamic and kinetic studies.

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Vanden Berk, Daniel E., Sarah C. Wesolowski, Mary J. Yeckley, Joseph M. Marcinik, Jean M. Quashnock, Lawrence M. Machia, and Jian Wu. "Extreme ultraviolet quasar colours from GALEX observations of the SDSS DR14Q catalogue." Monthly Notices of the Royal Astronomical Society 493, no. 2 (February 18, 2020): 2745–64. http://dx.doi.org/10.1093/mnras/staa411.

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ABSTRACT The rest-frame far to extreme ultraviolet (UV) colour–redshift relationship has been constructed from data on over $480\, 000$ quasars carefully cross-matched between SDSS Data Release 14 and the final GALEX photometric catalogue. UV matching and detection probabilities are given for all the quasars, including dependencies on separation, optical brightness, and redshift. Detection limits are also provided for all objects. The UV colour distributions are skewed redward at virtually all redshifts, especially when detection limits are accounted for. The median GALEX far-UV minus near-UV (FUV − NUV) colour–redshift relation is reliably determined up to z ≈ 2.8, corresponding to rest-frame wavelengths as short as 400 Å. Extreme UV (EUV) colours are substantially redder than found previously, when detection limits are properly accounted for. Quasar template spectra were forward modelled through the GALEX bandpasses, accounting for intergalactic opacity, intrinsic reddening, and continuum slope variations. Intergalactic absorption by itself cannot account for the very red EUV colours. The colour–redshift relation is consistent with no intrinsic reddening, at least for SMC-like extinction. The best model fit has a FUV continuum power-law slope αν, FUV = −0.34 ± 0.03 consistent with previous results, but an EUV slope αν, EUV = −2.90 ± 0.04 that is much redder and inconsistent with any previous composite value (all ≳ −2.0). The EUV slope difference can be attributed in part to the tendency of previous studies to preferentially select UV brighter and bluer objects. The weak EUV flux suggests quasar accretion disc models that include outflows such as disc winds.

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Journal articles on the topic 'UV-absorption detection'

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