scholarly journals UV spectroscopic properties of principal inorganic ionic species in natural waters

2018 ◽  
Vol 13 (4) ◽  
pp. 879-892 ◽  
Author(s):  
Jan Birkmann ◽  
Christoph Pasel ◽  
Michael Luckas ◽  
Dieter Bathen
Keyword(s):  
Wavelength Range ◽  
Significant Influence ◽  
Natural Waters ◽  
Uv Spectroscopy ◽  
Spectroscopic Properties ◽  
Ionic Species ◽  
Uv Spectra ◽  
Uv Spectrum ◽  
Ionic Solutions ◽  
Study Results

Abstract The UV spectroscopic properties of the principal inorganic ionic species in natural waters were investigated at 25 °C in the wavelength range 195 to 280 nm. All absorbing species were identified and the corresponding molar absorptivities were determined experimentally. No cations were found to influence the UV spectrum. Relatively high molar absorptivities were observed for iodide, bromide and nitrate. The UV spectra of natural waters were calculated using the molar absorptivities and compared with observed signals from synthetic samples. This enabled the dominant components to be determined. Both bromide and nitrate have significant influence on the UV spectrum of natural waters. The study results can be used to predict the UV spectra of ionic solutions and thus evaluate the suitability of UV spectroscopy for given measurement projects.

scholarly journals Exploring the Photodynamic Properties of Two Antiproliferative Benzodiazopyrrole Derivatives

2020 ◽  
Vol 21 (4) ◽  
pp. 1246 ◽  
Author(s):  
Concetta Imperatore ◽  
Mohammadhassan Valadan ◽  
Luciana Tartaglione ◽  
Marco Persico ◽  
Anna Ramunno ◽  
...  
Keyword(s):  
High Resolution Mass Spectrometry ◽  
Light Emitting Diode ◽  
Uv Spectroscopy ◽  
Ionic Species ◽  
Uv Spectra ◽  
Solution Ph ◽  
Null Cell ◽  
Degree Of Ionization ◽  
Promising Therapeutic Approach ◽  
Led Irradiation

The identification of molecules whose biological activity can be properly modulated by light is a promising therapeutic approach aimed to improve drug selectivity and efficacy on the molecular target and to limit the side effects compared to traditional drugs. Recently, two photo-switchable diastereomeric benzodiazopyrrole derivatives 1RR and 1RS have been reported as microtubules targeting agents (MTAs) on human colorectal carcinoma p53 null cell line (HCT 116 p53-/-). Their IC50 was enhanced upon Light Emitting Diode (LED) irradiation at 435 nm and was related to their cis form. Here we have investigated the photo-responsive behavior of the acid derivatives of 1RR and 1RS, namely, d1RR and d1RS, in phosphate buffer solutions at different pH. The comparison of the UV spectra, acquired before and after LED irradiation, indicated that the trans→cis conversion of d1RR and d1RS is affected by the degree of ionization. The apparent rate constants were calculated from the kinetic data by means of fast UV spectroscopy and the conformers of the putative ionic species present in solution (pH range: 5.7–8.0) were modelled. Taken together, our experimental and theoretical results suggest that the photo-conversions of trans d1RR/d1RS into the corresponding cis forms and the thermal decay of cis d1RR/d1RS are dependent on the presence of diazonium form of d1RR/d1RS. Finally, a photo-reaction was detected only for d1RR after prolonged LED irradiation in acidic medium, and the resulting product was characterized by means of Liquid Chromatography coupled to High resolution Mass Spectrometry (LC-HRMS) and Nuclear Magnetic Resonance (NMR) spectroscopy.

scholarly journals Enhanced ultraviolet absorption in graphene by aluminum and magnesium hole-arrays

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xueling Cheng ◽  
Yunshan Wang
Keyword(s):  
Numerical Study ◽  
Uv Spectroscopy ◽  
Single Layer ◽  
Hybrid Structure ◽  
Uv Absorption ◽  
Single Layer Graphene ◽  
Visible Range ◽  
Uv Spectrum ◽  
Hole Arrays ◽  
Uv Range

AbstractOptoelectronic devices in the UV range have many applications including deep-UV communications, UV photodetectors, UV spectroscopy, etc. Graphene has unique exciton resonances, that have demonstrated large photosensitivity across the UV spectrum. Enhancing UV absorption in graphene has the potential to boost the performance of the various opto-electronic devices. Here we report numerical study of UV absorption in graphene on aluminum and magnesium hole-arrays. The absorption in a single-layer graphene on aluminum and magnesium hole-arrays reached a maximum value of 28% and 30% respectively, and the absorption peak is tunable from the UV to the visible range. The proposed graphene hybrid structure does not require graphene to be sandwiched between different material layers and thus is easy to fabricate and allows graphene to interact with its surroundings.

Ultraviolet Spectrum Analysis of 1-methyl-3-butyl imidazole Tetrafluoroborate in Ethanol

2013 ◽  
Vol 389 ◽  
pp. 3-6
Author(s):  
Yang Yang Song ◽  
Peng Tian ◽  
Lu Yu
Keyword(s):  
Ionic Liquid ◽  
Linear Regression ◽  
Wavelength Range ◽  
Solution Concentration ◽  
Ultraviolet Spectrum ◽  
Linear Regression Equation ◽  
Uv Spectrum ◽  
Spectrometry Method ◽  
Spectrum Curve ◽  
Maximum Absorption Wavelength

1-methyl-3-butyl Imidazole chloride is prepared by 1methyl imidazole and chlorinated n-butane. BMIBF4 ionic liquid is prepared by BMIC and NaBF4 in the acetone. Scanning ionic liquid in 200~400nm wavelength range, get UV-spectrum curve. The ionic liquid used in the experiment has obvious absorption in 200~400nm wavelength range, and the maximum absorption wavelength determined by ultraviolet spectrometry method is 222nm. Linear regression equation is y =0.02311x+0.02861. Correlation coefficient is 0.99925, indicating there is high related degree between the solution concentration and the absorbance value. The linear range of BMIBF4 ionic liquid in the ethanol is 1-75 mg/L. Take samples randomly and have a repeated determination 5 times, the precision is RSD=0.25%, the recovery rate is between 97.4%~102%.

scholarly journals Cannabis Yield Increased Proportionally With Light Intensity, but Additional Ultraviolet Radiation Did Not Affect Yield or Cannabinoid Content

2021 ◽  
Author(s):  
David Llewellyn ◽  
Scott Golem ◽  
Elizabeth Foley ◽  
Steve Dinka ◽  
Max Jones ◽  
...  
Keyword(s):  
Ultraviolet Radiation ◽  
Harvest Index ◽  
Cannabis Sativa ◽  
Scientific Evidence ◽  
Uv Spectra ◽  
Neutral Form ◽  
Uv Spectrum ◽  
Yield And Quality ◽  
Controlled Environments ◽  
The Impact

Cannabis (Cannabis Sativa L.) is now legally produced in many regions worldwide. Cannabis flourishes under high light intensities (LI); making it an expensive commodity to grow in controlled environments, despite its exceptionally high market value. It is commonly believed that cannabis secondary metabolite levels may be enhanced both by increasing LI and by exposing crops to ultraviolet radiation (UV). However, there is sparse scientific evidence to guide cultivators. Therefore, the impact of LI and UV on yield and quality must be elucidated to enable cultivators to optimize their lighting protocols. We explored the effects of LI, ranging from 350 to 1400 μmol m-2 s-1 and supplemental UV spectra on cannabis yield and potency. There were no spectrum effects on inflorescence yield, but harvest index under UVA+UVB was reduced slightly (1.6%) vs. the control. Inflorescence yield increased linearly from 19.4 to 57.4 g/plant and harvest index increased from 0.565 to 0.627, as LI increased from 350 to 1400 μmol m-2 s-1. Although there were no UV spectrum effects on total equivalent Δ9-tetrahydrocannabinol (T-THC) content in leaves, the neutral form, THC, was 30% higher in UVA+UVB vs. control. While there were no LI effects on inflorescence T-THC content, the content of the acid form (THCA) increased by 20% and total terpenes content decreased by 20% as LI increased from 350 to 1400 μmol m-2 s-1. High LI can substantially increase cannabis yield and quality, but we found no commercially-relevant benefits of adding supplemental UV radiation to indoor cannabis production.

scholarly journals Ultraviolet Spectroscopy Used to Fingerprint Five Wild-Grown Edible Mushrooms (Boletaceae) Collected from Yunnan, China

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yan Li ◽  
Ji Zhang ◽  
Tao Li ◽  
Tianwei Yang ◽  
Yuanzhong Wang ◽  
...  
Keyword(s):  
Cluster Analysis ◽  
Discriminant Analysis ◽  
Hierarchical Cluster Analysis ◽  
Visual Discrimination ◽  
Uv Spectroscopy ◽  
Hierarchical Cluster ◽  
Uv Spectra ◽  
Edible Mushrooms ◽  
Ultraviolet Spectroscopy

Nowadays, wild-grown edible mushrooms which are natural, nutritious, and healthy get more and more popular by large consumers. In this paper, UV spectra of different Boletaceae mushrooms with the aid of partial least squares discriminant analysis (PLS-DA) and hierarchical cluster analysis (HCA) were shown to be a practical and rapid method for discrimination purpose. The specimens of Boletus edulis, Boletus ferrugineus, Boletus tomentipes, Leccinum rugosiceps, and Xerocomus sp. were described based on the UV spectra. From the results, all the specimens were characterized by strong absorption at the wavelengths of 274 and 284 nm and showed the shoulder at 296 nm. However, changes could be seen in the peak heights at the same wavelength for different samples. After analyzing by chemometrics, visual discrimination among samples was presented and the relationships among them were also obtained. This study showed that UV spectroscopy combined with chemometrics methods could be used successfully as a simple and effective approach for characterization of these five wild-grown edible mushrooms at species and genus levels. Meanwhile, this rapid and simple methodology could also provide reference for the discrimination of edible mushrooms.

Development and Validation of UV Spectroscopy Method for the Estimation of Dolutegravir in Bulk and Pharmaceutical Dosage Form

2021 ◽  
pp. 188-190
Author(s):  
Vaishnavi Dulange ◽  
G.B. Gajeli
Keyword(s):  
Dosage Form ◽  
Uv Spectroscopy ◽  
Spectroscopic Method ◽  
Water Mixture ◽  
Uv Spectrum ◽  
Pharmaceutical Dosage Form ◽  
Highly Sensitive ◽  
Development And Validation ◽  
The Given ◽  
Regression Correlation

UV spectroscopic method was developed for the estimation of Dolutegravir in bulk and Formulation.The UV spectrum of Dolutegravir in methanol and water mixture showed λ max at 254nm. Beer’s law is valid in the concentration range of 10-50µg/ml. This method was validated for linearity, accuracy, precision, LOD and LOQ. The method has demonstrated excellent linearity over the range of 10-50µg/ml with regression equation y = 0.030x + 0.008 and regression correlation coefficient r2= 0.998. Moreover, the method was found to be highly sensitive with LOD (2.056μg/ml) and LOQ (6.230μg/ml). Depending on results the given method can be successfully applied for assay of Dolutegravir in formulation.

scholarly journals Spectroscopic Properties of the Nucleus of NGC 6826

1993 ◽  
Vol 155 ◽  
pp. 86-86
Author(s):  
B. Altner ◽  
S.R. Heap ◽  
I. Hubeny
Keyword(s):  
Line Profile ◽  
Central Star ◽  
Spectroscopic Properties ◽  
Uv Spectra ◽  
Profile Fitting

We continue the trend of finding discrepancies in the values of central star masses derived from photospheric line profile fitting and other methods in our analyses of ground-based and UV spectra of the nucleus of NGC 6826.

scholarly journals Exploring Abundance and Isotope Anomalies in CP Stars with the HST/GHRS: High Resolution UV Spectroscopy of χ Lupi

1993 ◽  
Vol 138 ◽  
pp. 42-59 ◽  
Author(s):  
David S. Leckrone ◽  
Glenn M. Wahlgren ◽  
Sveneric G. Johansson ◽  
Saul J. Adelman
Keyword(s):  
High Resolution ◽  
Uv Spectroscopy ◽  
Uv Spectra ◽  
Heavy Elements

AbstractWe are using the HST/GHRS in a long-term program to obtain UV spectra of unprecedented resolution and precision for bright, ultra-sharp-lined Bp (HgMn) stars and comparable normal stars. To date we have doubled the number of heavy elements for which abundances may be estimated in χ Lupi, and have obtained the first observations of Hg III lines with which to test diffusion scenarios for its extreme Hg isotope anomaly.

scholarly journals The circumstellar matter in the Be + K binary KX and seen in the uv spectra

1987 ◽  
Vol 122 ◽  
pp. 493-495
Author(s):  
S. Štefl
Keyword(s):  
Circumstellar Matter ◽  
Uv Spectra ◽  
Be Stars ◽  
Uv Spectrum ◽  
Spectroscopic Characteristics ◽  
Dependent Behaviour

KX And (HD 218393) belongs to well-known and often observed Be stars. The periodicity of spectroscopic characteristics as well as other observations led to the conclusion that the star is a peculiar interacting binary (Harmanec et al. 1980). The aim of this paper is to present the phase-dependent behaviour of the UV spectrum of the star.

Determination of Seawater Salinity by Ultraviolet Spectroscopic Measurements

1997 ◽  
Vol 51 (9) ◽  
pp. 1294-1302 ◽  
Author(s):  
Vito Di Noto ◽  
Mauro Mecozzi
Keyword(s):  
Organic Matter ◽  
Uv Spectroscopy ◽  
Sample Pretreatment ◽  
Uv Spectra ◽  
Linear Calibration ◽  
Synthetic Seawater ◽  
Seawater Salinity ◽  
Seawater Samples ◽  
Nitrate Species

A method for the determination of seawater salinity by ultraviolet (UV) spectroscopy is proposed. The effects of single salt concentrations and of salinity on UV absorption in the 190–250-nm range were investigated. These studies revealed that the absorption spectrum of a solution with a given salinity is due mainly, in order, to KBr >MgCl 2>NaCl. The influence of the temperature and salt concentration on UV spectra was studied by using synthetic seawater samples with the salinities ranging from 1 to 50 parts per thousand (%). Results showed that, in the absence of interferences, the most sensitive and reliable conditions for measuring the salinity are at 212 nm and at temperatures in the range of 25–30 °C. Under these conditions this method shows quite linear calibration curves and allows us to perform salinity determinations in seawater solutions at concentrations as low as 4%. Moreover, it requires no sample pretreatment and offers a precision of 0.20%. The proposed method is very simple and rapid for laboratory and on-board analysis. Finally, the interference of organic matter, nitrite, and nitrate species with the salinity determinations was investigated. These studies show that organic matter does not interfere at concentrations of carbon lower than 1 mg/L and at 210 nm. Interferences due to NO− x species can be ignored if these species are dissolved in solution at concentrations lower than ≈0.2 mg/L and the analyses are carried out at wavelengths lower than 212 nm.

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