Characterization and identification of a plastic-like off-odor in mineral water

2009 ◽  
Vol 9 (3) ◽  
pp. 299-309 ◽  
Author(s):  
A. Strube ◽  
A. Buettner ◽  
Carola Groetzinger
Keyword(s):  
Carbonyl Compounds ◽  
Mineral Water ◽  
Uv Light ◽  
Light Exposure ◽  
Stir Bar Sorptive Extraction ◽  
Compound Formation ◽  
Natural Sunlight ◽  
Sorptive Extraction ◽  
Artificial Uv ◽  
First Time

A specific mineral water off-odor, the so-called “sunlight” flavor produced after UV light exposure, was characterized by sensory analysis in different mineral water samples and ranked according to overall odor intensity. The odorants were isolated by means of solvent extraction and stir bar sorptive extraction (SBSE) techniques, respectively. Analyses were performed with two-dimensional (2D) high resolution gas chromatographic (HRGC) separation and parallel mass spectrometric (MS) and olfactometric (O) detection. Additionally, analyses of off-odor-free samples exposed to natural sunlight or to “artificial” UV radiation (replicating natural sunlight) were analyzed to assess off-odor compound formation. 14 common characteristic odorants in commercial off-odor and irradiated samples were identified. These were predominantly saturated and mono or di-unsaturated carbonyl compounds, with several substances exhibiting the characteristic fatty and plastic-like odor impressions. Eight of the compounds identified were detected for the first time as off-odor “sunlight” flavor contributors to mineral water and had amongst the highest flavor dilution (FD) factors in the extracted samples.

Photocatalytic properties of TiO2 for the degradation of O3: Examined by environmental parameters

2021 ◽  
Vol 02 ◽  
Author(s):  
Magnus Christoffer Skov ◽  
Steffen Enggaard Kristensen ◽  
Teis Nørgaard Mikkelsen
Keyword(s):  
Relative Humidity ◽  
Light Intensity ◽  
Uv Light ◽  
Light Exposure ◽  
Environmental Parameters ◽  
Photocatalytic Properties ◽  
Uptake Coefficient ◽  
Ambient Conditions ◽  
Natural Sunlight ◽  
Photocatalytic Effect

Background: This paper describes how environmentally relevant parameters affect titanium dioxide's photocatalytic properties (TiO2) to decompose ozone (O3). Methods: Thus, experiments have been carried out in a box chamber with TiO2 coated roofing membrane samples to determine the significance of light intensity, temperature, initial O3 concentration, and relative humidity. Furthermore, an outdoor experiment has been conducted where the roofing membrane was subjected to natural sunlight. Results: The results show a significant photocatalytic effect of TiO2. The half-life of the O3 decay curve is 5.8 min in near-ambient UV-light exposure compared with 7.1 min in dark conditions. Experiments conducted at higher light intensity show a more extensive degradation of O3, where the value of the reactive uptake coefficient increases from 0.044 to 0.051. Also, the measurements carried out under natural sunlight show a photocatalytic effect where the uptake coefficient value is 0.046. A larger photocatalytic effect is detected for the experiments conducted at 283 K and 303 K temperatures compared with experiments under standard conditions. Conclusion: Experiments carried out with a very high initial concentration of O3 show that 28.1 μg of O3 is decomposed than ambient conditions, where 2.3 μg is destroyed. This demonstrates that light intensity, temperature, ozone concentration, and relative humidity significantly impact TiO2's degradation of O3.

MIL-101/GO Coated Stir Bar for SBSE to Determine Azo Dyes in Water Samples by UV–Vis Spectrophotometric Method

Nano LIFE ◽  
2015 ◽  
Vol 05 (03) ◽  
pp. 1542004 ◽  
Author(s):  
Qiong Yi ◽  
Ling Li ◽  
Wei Hong ◽  
Lu Fan
Keyword(s):  
Azo Dyes ◽  
Water Samples ◽  
Metal Organic Framework ◽  
Sol Gel ◽  
Enrichment Factors ◽  
Stir Bar Sorptive Extraction ◽  
Sunset Yellow ◽  
Sorptive Extraction ◽  
Metal Organic ◽  
First Time

A composite of chromium (III) terephthalate metal-organic framework and graphene oxide (MIL-101/GO) coated stir bar was prepared by sol–gel technique for the first time and was employed for stir bar sorptive extraction (SBSE) of trace azo dyes amaranth, sunset yellow and carmine from water samples followed by UV–Vis spectrophotometric detection. A MIL-101/GO coating was first created on the glass bar surface. MIL-101/GO and MIL-101/GO coated stir bars were characterized. The enrichment factors of azo dyes by SBSE have been investigated in detail, and the optimized experimental parameters were obtained. Under the optimal conditions, a method for determination of trace amount of azo dyes was setup, and the detection limits of amaranth, sunset yellow and carmine were 2.3 ng/mL, 1.7 ng/mL and 1.6 ng/mL. The proposed method was successfully applied for the analysis of the three azo dyes in water samples.

scholarly journals Determination of Saffron Volatiles by HS-SBSE-GC in Flavored Cured Ham

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2073
Author(s):  
Elena M. Gómez-Sáez ◽  
Natalia Moratalla-López ◽  
Cándida Lorenzo ◽  
Herminia Vergara ◽  
Gonzalo L. Alonso
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Volatile Compound ◽  
Meat Products ◽  
Stir Bar Sorptive Extraction ◽  
Gas Chromatography Mass Spectrometry ◽  
Food Industries ◽  
Sorptive Extraction ◽  
First Time

At present, the development of new agri-food products, including flavored meat products presented in ready-to-eat vacuum packs, is encouraged. The addition of ingredients used as flavoring agents creates the need to be able to determine the volatile compounds responsible for their characteristic aroma. The aim of this study is to propose, develop, and validate a new method that uses headspace-stir bar sorptive extraction-gas chromatography/mass spectrometry (HS-SBSE-GC/MS) to determine the saffron aroma in cured ham flavored with this spice. Results showed that safranal was the main volatile compound that could be identified and quantified in cured ham flavored with saffron. This analytical method was adequate in terms of linearity, selectivity, sensitivity, and accuracy. To our knowledge, this is the first time that an HS-SBSE-GC/MS method for determining the saffron aroma of flavored cured ham has been developed and validated, and it is of interest to agri-food industries.

Decomposition of Microcystis aeruginosa and Microcystin-LR by TiO2 Oxidation Using Artificial UV Light or Natural Sunlight

2012 ◽  
Vol 15 (1) ◽  
Author(s):  
Lívia X. Pinho ◽  
Joana Azevedo ◽  
Vítor M. Vasconcelos ◽  
Vítor J. P. Vilar ◽  
Rui A. R. Boaventura
Keyword(s):  
Microcystis Aeruginosa ◽  
Uv Light ◽  
Natural Sunlight ◽  
Artificial Uv

AbstractIn this study, it is reported the destruction of Microcystis aeruginosa and the toxin microcystin-LR (MC-LR) by photolysis and TiO

4 Pattern Recognition for Healing Burns to Compute Evidence: Space Syntax and Machine Learning Analysis of Burns Center Karachi

2013 ◽  
Vol 1 (1) ◽  
pp. 13
Author(s):  
Javaria Manzoor Shaikh ◽  
JaeSeung Park
Keyword(s):  
Pattern Recognition ◽  
Prediction Models ◽  
Uv Light ◽  
Healing Process ◽  
Space Syntax ◽  
Depth Map ◽  
Routine Tasks ◽  
Hyper Plane ◽  
First Time ◽  
Learning Analysis

Usually elongated hospitalization is experienced byBurn patients, and the precise forecast of the placement of patientaccording to the healing acceleration has significant consequenceon healthcare supply administration. Substantial amount ofevidence suggest that sun light is essential to burns healing andcould be exceptionally beneficial for burned patients andworkforce in healthcare building. Satisfactory UV sunlight isfundamental for a calculated amount of burn to heal; this delicaterather complex matrix is achieved by applying patternclassification for the first time on the space syntax map of the floorplan and Browder chart of the burned patient. On the basis of thedata determined from this specific healthcare learning technique,nurse can decide the location of the patient on the floor plan, hencepatient safety first is the priority in the routine tasks by staff inhealthcare settings. Whereas insufficient UV light and vitamin Dcan retard healing process, hence this experiment focuses onmachine learning design in which pattern recognition andtechnology supports patient safety as our primary goal. In thisexperiment we lowered the adverse events from 2012- 2013, andnearly missed errors and prevented medical deaths up to 50%lower, as compared to the data of 2005- 2012 before this techniquewas incorporated.In this research paper, three distinctive phases of clinicalsituations are considered—primarily: admission, secondly: acute,and tertiary: post-treatment according to the burn pattern andhealing rate—and be validated by capable AI- origin forecastingtechniques to hypothesis placement prediction models for eachclinical stage with varying percentage of burn i.e. superficialwound, partial thickness or full thickness deep burn. Conclusivelywe proved that the depth of burn is directly proportionate to thedepth of patient’s placement in terms of window distance. Ourfindings support the hypothesis that the windowed wall is mosthealing wall, here fundamental suggestion is support vectormachines: which is most advantageous hyper plane for linearlydivisible patterns for the burns depth as well as the depth map isused.

Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

2018 ◽  
Author(s):  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Rachel Evans
Keyword(s):  
Real Time ◽  
Absorption Spectroscopy ◽  
Self Assembly ◽  
Uv Light ◽  
Wormlike Micelles ◽  
Tetraethylene Glycol ◽  
Light Illumination ◽  
First Time ◽  
Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such as<i></i>drug delivery and micellar catalysis. Currently, their behaviour in the equilibrium <i>cis-</i>and <i>trans</i>-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>) using small-angle neutron scattering (SANS). We show that the incorporation of <i>in-situ</i>UV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>could switch between wormlike micelles (<i>trans</i>native state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked <i>in</i><i>-situ</i>through combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

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