Статті в журналах: "UV-VIS detector"

1

Kammer, Frank v. d., and Ulrich Förstner. "Natural colloid characterization using flow-field-flow-fractionation followed by multi-detector analysis." Water Science and Technology 37, no. 6-7 (March 1, 1998): 173–80. http://dx.doi.org/10.2166/wst.1998.0750.

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A design for a flow-field-flow-fractionation with UV/VIS-, fluorescence- and laser-light-scattering-detectors is presented and tested with extracts from a humus rich horizon of a gleyic podzol. It is tested to show how the system can retrieve relevant information about changes in the constitution of the colloid samples. The main objective is the investigation of colloid alteration during processes provoked by main geochemical driving forces (e.g. pH or ionic strength), in this case changes of redox potential. Therefore fluorescence- and UV/VIS-fractograms are taken at different wavelengths and compared. Particle diameters of natural colloids are calculated from laser-light-scattering data and compared with reference standards.

2

Studziński, Waldemar, and Alicja Gackowska. "Removal of 2-phenylbenzimidazole-5-sulfonic acid using heterogeneous photocatalysis." Acta Innovations, no. 28 (July 1, 2018): 5–13. http://dx.doi.org/10.32933/actainnovations.28.1.

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UV filters are classified as environmental pollutants (emerging pollutants). One of the most frequently detected UV filters in real samples is 2-phenylbenzimidazole-5-sulfonic acid (PBSA). It has been shown that conventional technologies applied in sewage treatment plants are not adapted for complete removal of sunscreen agents. Therefore, there is a trend to undertake activities leading to improvement of water quality by enhancing treatment methods. This is important due to the fact that in an aqueous environment, in the presence of UV radiation or sunlight irradation, PBSA generates reactive oxygen species that can damage the DNA of living organisms. The aim of study was to investigate an effect of pH and TiO2 on PBSA stability in the presence of UV radiation. It was found that the rate of PBSA degradation depends on the catalyst dose and pH of solution. The photocatalysis reaction was carried out in a Heraeus laboratory exposure set equipped with a 150 W mediumpressure mercury lamp. The course of PBSA degradation process as a function of time was monitored using UV/VIS spectrophotometer and liquid chromatograph equipped with UV-Vis detector.

3

MOSAYEBI, PEGAH, DAVOUD DORRANIAN, and KASRA BEHZAD. "INVESTIGATING THE IMPLEMENTATION OF ZnO NANOPARTICLES AS A TUNABLE UV DETECTOR FOR DIFFERENT SKIN TYPES." Surface Review and Letters 25, no. 02 (February 2018): 1850062. http://dx.doi.org/10.1142/s0218625x18500622.

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A facile chemical reduction method was used to synthesize ZnO nanoparticles (NPs) in ethylene glycol solvent at two different calcination temperatures. As a result of variation in the calcination temperature, ZnO NPs with two different sizes were achieved. The NPs were investigated for their structural and optical characteristics using X-ray diffraction and ultraviolet (UV)–Vis spectroscopy. The synthesized ZnO NPs exhibited a hexagonal structure with sizes of 46 and 65[Formula: see text]nm. The synthesized NPs were then used to investigate dye photocatalytic behavior of products as a tunable UV detector for different skin types. The dye degradation and decolorization of methylene blue in the presence of ZnO NP, following UV radiation as a function of time, were studied at different pH levels. The optical absorption spectra were then taken every 15[Formula: see text]min for all samples. The UV–Vis spectroscopy spectra revealed that optical absorption of solution was decreased upon UV exposure as a function of time. Photocatalytic reaction indicated that the dye degradation and decolorization rate were accelerated with the increase of pH level. Therefore, a tunable UV detector for different skin types could be engineered by varying the pH level of solution to avoid human skin burning.

4

Alister G., Willis, and Saharudin Haron. "Synthesis of composite thin-film polymer consisting of tungsten and zinc oxide as hydrogen gas detector." E3S Web of Conferences 90 (2019): 01008. http://dx.doi.org/10.1051/e3sconf/20199001008.

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A composite polymer consisting of polyaniline (PANI) was synthesised via oxidative polymerisation by varying concentrations of transitional metal oxides and the presence of a hydrogen dissociation catalyst, palladium (Pd). The metal oxides chosen for this study were tungsten oxide (WO3) and zinc oxide (ZnO). The composite polymer samples were characterised using Fourier transform infrared (FTIR) spectroscopy where ultraviolet-visible (UV-Vis) spectroscopy was used to observe the optical changes of the thin films due to exposure to hydrogen. The FTIR spectra obtained confirmed the synthesis of PANI composite. Based on the UV-VIS analysis, PANI-ZnO composite polymer showed the highest difference in peak intensity before and after exposure to hydrogen with 11.4% difference.

5

Jooybari, Banin Shakeri, Hossein Afarideh, Mohammad Lamehi Rachti, and Mitra Ghergherehchi. "Modification on chemical and optical properties of PADC polymer by ArF laser (193 nm) irradiation." Journal of Polymer Engineering 35, no. 4 (May 1, 2015): 359–65. http://dx.doi.org/10.1515/polyeng-2014-0149.

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Abstract Poly allyl diglycol carbonate (PADC) has been irradiated by ArF(UV)-laser light (wavelength 193 nm) at different fluences and pulse numbers in order to investigate the photo degradation of chemical molecular structure. The photo-induced chemical reactions and photo-degradation mechanism at the irradiated polymer surface have been clarified by ultraviolet-visible (UV-Vis) spectrum and FTIR spectrum analyses. Optical and surface modifications of irradiated samples have been studied by refractive index and water contact angle measurements. Using the UV-Vis spectra, Urbach’s energy (Eu), indirect and direct band gaps energy (Eg) of unirradiated and UV-laser irradiated samples were determined. The UV-Vis and FTIR spectra analysis show that photo degradation and photo oxidation of polymer caused free-radical generation. In the presence of air, free-radical generation induced by UV-laser light followed by bond scission and cross-linking process will finally produce new products. New product generation can be affected on chemical and optical properties of irradiated samples. The irradiated PADC at various fluences in the range of medium to high demonstrate improvement of refractive index, and this is highly important in plastic lens technology. The obtained results reveal that chemical modification could affect track parameters when PADC is used as a nuclear track detector.

6

Singh, Surinder, and Sangeeta Prasher. "UV–VIS spectroscopic and etching studies of IR exposed CR-39 plastic track detector." Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 215, no. 1-2 (January 2004): 169–73. http://dx.doi.org/10.1016/s0168-583x(03)01815-9.

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7

Mellouki, I., O. Touayar, T. Ktari, J. Bastie, and N. Yacoubi. "A method for calibrating of a trap pyroelectric detector in the UV–vis domain." Sensors and Actuators A: Physical 120, no. 2 (May 2005): 437–40. http://dx.doi.org/10.1016/j.sna.2005.01.018.

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8

Strauss, Holger M., Engin Karabudak, Saroj Bhattacharyya, Andreas Kretzschmar, Wendel Wohlleben, and Helmut Cölfen. "Performance of a fast fiber based UV/Vis multiwavelength detector for the analytical ultracentrifuge." Colloid and Polymer Science 286, no. 2 (December 19, 2007): 121–28. http://dx.doi.org/10.1007/s00396-007-1815-5.

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9

Gebregziabher, Berhane Sibhatu, Shengrui Zhang, Jie Qi, Muhammad Azam, Suprio Ghosh, Yue Feng, Yuanyuan Huai, Jing Li, Bin Li, and Junming Sun. "Simultaneous Determination of Carotenoids and Chlorophylls by the HPLC-UV-VIS Method in Soybean Seeds." Agronomy 11, no. 4 (April 13, 2021): 758. http://dx.doi.org/10.3390/agronomy11040758.

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Soybean contains nutritional bioactive compounds, including carotenoids associated with human health benefits. Carotenoids are applicable in pharmaceuticals/nutreceuticals, cosmetic, and mainly food industries. However, an efficient and accurate method for carotenoid and chlorophyll detection and quantification has not yet been developed and validated for soybean seeds. The need for a rapid and reliable analysis method has become increasingly important. Thus, this study was initiated to develop and validate a simple, rapid, and selective reversed-phase high-performance liquid chromatographic (RP-HPLC) method for the simultaneous determination of lutein, zeaxanthin, α-carotene, β–carotene, β–cryptoxanthin, and chlorophyll–a and –b in soybean flour sample (100.00 mg) extracted using ethanol-acetone (1:1) solvents at a volume of 1.50 mL. Interestingly, the effective separation technique was achieved using the mobile phases of methyl tert-butyl ether, methanol containing 10 mM ammonium acetate, and water delivered at a 0.90 mL min−1 flow rate through a C30YMC Carotenoid (250 × 4.6 mm I.D., S-5 µm) column coupled with a UV-VIS detector set at 450 nm. The detector response was linear from 0.05–30.00 μg mL−1 with a coefficient of determination (R2) of 0.9993–0.9999. The validated method was sensitive with a detection limit (LOD) of 0.0051–0.0300 μg mL−1 and 0.0155–0.0909 μg mL−1 for the quantification limit (LOQ). The recovery values were from 83.12–106.58%, and the repeatability precision ranged from 1.25–4.20% and 0.15–0.81% for the method and system, respectively. The method showed adequate precision with a relative standard deviation smaller than 3.00%. This method was also found to be applicable for profiling carotenoids and chlorophylls in other legumes. In summary, this method was successfully implemented for qualitative and quantitative determination of major carotenoids and chlorophylls in soybean and other legume seeds, which are beneficial to food industry and quality breeding programs to meet human nutrition demands globally.

10

Journal, Baghdad Science. "Determination of Water-Soluble Vitamins in Iraqi Honey Bee and Compare with Others Types by High –Performance Liquid Chromatography." Baghdad Science Journal 13, no. 2 (June 5, 2016): 447–57. http://dx.doi.org/10.21123/bsj.13.2.447-457.

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High-performance liquid chromatographic methods are used for the determination of water-soluble vitamins with UV-Vis. Detector. A reversed-phase high-performance liquid chromatographic has been developed for determination of water-soluble vitamins. Identification of compounds was achieved by comparing their retention times and UV spectra with those of standards solution. Separation was performed on a C18 column, using an isocratic 30% (v/v) acetonitril in dionozed water as mobile phase at pH 3.5 and flow rate 1.0m/min. The method provides low detection and quantification limits, good linearity in a large concentration interval and good precision. The detection limits ranged from 0.01 to 0.025µg/ml. The accuracy of the method was tested by measuring average recovery values ranged between 94% - 101 %. For standerd solution, and 93%-99% of honey bee samples.

11

León, L., J. J. Maraver, J. Carbajo, and J. D. Mozo. "Simple and multi-configurational flow-cell detector for UV–vis spectroelectrochemical measurements in commercial instruments." Sensors and Actuators B: Chemical 186 (September 2013): 263–69. http://dx.doi.org/10.1016/j.snb.2013.06.024.

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12

Kicinski, H. G., and A. Kettrup. "Analysis of phenolic compounds in spruce needle extracts using an UV-VIS-diode array detector." Fresenius' Zeitschrift für analytische Chemie 327, no. 1 (January 1987): 82–83. http://dx.doi.org/10.1007/bf00474590.

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13

Kicinski, H. G., and A. Kettrup. "Analysis of phenolic compounds in spruce needle extracts using an UV-VIS-diode array detector." Fresenius' Zeitschrift für analytische Chemie 327, no. 5-6 (January 1987): 535–38. http://dx.doi.org/10.1007/bf00487242.

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14

Gülfen, Mustafa, Yazgı Canbaz, and Abdil Özdemir. "Simultaneous Determination of Amoxicillin, Lansoprazole, and Levofloxacin in Pharmaceuticals by HPLC with UV–Vis Detector." Journal of Analysis and Testing 4, no. 1 (January 2020): 45–53. http://dx.doi.org/10.1007/s41664-020-00121-4.

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15

Zimmer, C. M., C. Asbeck, D. Lützenkirchen-Hecht, P. Glösekötter, and K. T. Kallis. "Backside Illumination of an Electronic Photo Ionization Detector Realized by UV Transparent Thin Films." Journal of Nano Research 25 (October 2013): 55–60. http://dx.doi.org/10.4028/www.scientific.net/jnanor.25.55.

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LaB6/ITO films were prepared by magnetron sputtering technique on borosilicate glass substrates. The transmittance of ITO and LaB6/ITO films was analyzed by using UV/VIS spectrophotometer, whereby the sheet resistance of the ITO films was measured by four point probes. The effect of temperature and post-annealing processes on ITO film properties optimizing UV transparency and sheet resistance were investigated in detail. ITO films with an optimized thickness of 31 nm exhibited a low sheet resistance of 64 Ω/sq and a high ultraviolet transmittance of 81% at a wavelength of 365 nm. The additional LaB6 layer controls the UV transmittance behavior of the bilayer structure of LaB6/ITO by improving the photon absorption with thicker LaB6 films. The work function of LaB6 (32 nm)/ITO films with a value of 4.98 eV was measured by ultraviolet photoelectron spectroscopy (UPS).

16

Kolar, Wesley, and Ron Williams. "Comparison of Interferogram Noises in the Ultraviolet and Visible Regions." Applied Spectroscopy 46, no. 4 (April 1992): 615–19. http://dx.doi.org/10.1366/0003702924124989.

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The sources of noise in ultraviolet (UV), visible, and near-infrared (NIR) interferograms acquired with silicon and germanium diodes as well as photomultiplier tube (PMT) detectors have been investigated. Similar conditions were used with each detector so that noises could be compared with minimal bias. Interferograms were produced from tungsten and deuterium lamps as well as an inductively coupled plasma (ICP). Data were collected from two instruments; a Mattson Sirius 100 UV/Vis spectrometer, and a Chelsea Instruments FT 500. The signal was the average of 4 to 100 interferograms, while the standard deviation of the data was the noise. In addition to the average and the standard deviation, which are the first two moments of the frequency distribution, the third moment (known as skew) was employed to analyze the symmetry of noise distributions.

17

Suprianto, Suprianto, Darwin Syamsul, and Muhammad Deddy Harfiansyah. "Aplikasi Metode Penetapan Kadar Rutin Parasetamol PT. Kimia Farma, Tbk Secara HPLC pada Sediaan Tablet Generik dan Bermerek di Medan." Jurnal Indah Sains dan Klinis 1, no. 1 (December 10, 2020): 1–5. http://dx.doi.org/10.52622/jisk.v1i1.1.

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Parasetamol merupakan salah satu obat yang bersifat analgesik dan antipiretik, yang diproduksi sebagai obat generik maupun bermerek. Tujuan penelitian untuk mengetahui mutu berdasarkan kadar parasetamol dalam sediaan tablet generik dan bermerek yang beredar di Medan. Penelitian menggunakan HPLC Alliance e2696 Detector UV/Visible 2489, Column µ Bondapak TM C-18: 10 µm 125A 3,9x300 mm, Spektrofotometer UV-Vis Agilent 8453. Metode yang digunakan merupakan metote penetapan kadar rutin parasetamol PT. Kimia Farma. Hasil penelitian menunjukkan bahwa kadar parasetamol dalam sediaan tablet sebesar 97,05% - 106,04%, sesuai Farmakope Indonesia Edisi V, tidak kurang dari 90% dan tidak lebih dari 110%.

18

Willis, Alister Genndi, and Saharudin Haron. "Synthesis and characterization of composite polyaniline as hydrogen gas detector." Malaysian Journal of Fundamental and Applied Sciences 13, no. 4 (December 26, 2017): 559–62. http://dx.doi.org/10.11113/mjfas.v0n0.562.

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Composite polymer consisting polyaniline (PANI) and zinc oxide (ZnO) were synthesized via oxidative polymerization of aniline. The composite PANI thin films were characterized by FTIR spectroscopy and their optical properties towards hydrogen gas were investigated using UV-vis spectroscopy. The FTIR spectra obtained verified the synthesis PANI/ZnO composite. From the experimental results, it was found that with increasing zinc oxide content in the composite cause the transmittance to decrease. The transmittance of the thin films slightly increased after exposed to hydrogen gas. PANI-ZnO (10%w.t.) exhibited best response compared to other composition with the highest transmittance peak difference of 11.4%.

19

Ahad, Irma Zulayka Mohamad, Sulaiman Wadi Harun, Seng neon Gan, and Sook Wai Phang. "Application of Fiber Bragg Grating Sensor coated with Polyaniline as an optical Sensor for chloroform detection." Polymers and Polymer Composites 25, no. 7 (September 2017): 555–62. http://dx.doi.org/10.1177/096739111702500707.

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Fiber Bragg Grating (FBG) sensor coated with PAni was designed as a sensing device in chloroform detection. PAni thin film was synthesized through chemical oxidation method by using aniline (Ani) as a monomer, ammonium persulphate (APS) as an initiator and dioctyl sodium sulfosuccinate (AOT) as a dopant. The chemical structure of PAni thin film was confirmed by using Fourier transform infrared (FTIR) and ultraviolet-visible (UV-Vis) spectrometer. The conducting behaviour of PAni thin film (1.157 × 10−2 S/cm) was determined by using four-point probe measurement. In the optical sensor part, FBG was etched in hydrofluoric acid solution (48% HF) to remove the cladding layer on fiber before coated with PAni. The response of this sensor was monitored based on the different of Bragg wavelength shift at ∼1557 nm in an optical spectrum analyzer (OSA) detector. PAni-coated FBG significantly increased in the Bragg wavelength shift (sensitivity = 0.0009) compared with uncoated FBG (sensitivity = 0.0002). The interaction between PAni and chloroform was significantly confirmed by the “polaron peak ratio” (Pf/Pi) and “quinoid and benzenoid peak ratio” (IQ/ IB) through UV-vis and FTIR spectroscopy analysis. In this study, FBG sensor coated with PAni thin film had been found as an efficient sensor in chloroform detection with fast response time (7 s).

20

D’Urzo, Annalisa, Angela De Simone, Jessica Fiori, Marina Naldi, Andrea Milelli та Vincenza Andrisano. "Direct determination of GSK-3β activity and inhibition by UHPLC-UV–vis diode arrays detector (DAD)". Journal of Pharmaceutical and Biomedical Analysis 124 (травень 2016): 104–11. http://dx.doi.org/10.1016/j.jpba.2016.02.029.

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21

David, G., A. Miffre, B. Thomas, and P. Rairoux. "Sensitive and accurate dual-wavelength UV-VIS polarization detector for optical remote sensing of tropospheric aerosols." Applied Physics B 108, no. 1 (May 23, 2012): 197–216. http://dx.doi.org/10.1007/s00340-012-5066-x.

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22

Chiş, Maria Simona, Adriana Păucean, Simona Maria Man, Dan Cristian Vodnar, Bernadette-Emoke Teleky, Carmen Rodica Pop, Laura Stan, et al. "Quinoa Sourdough Fermented with Lactobacillus plantarum ATCC 8014 Designed for Gluten-Free Muffins—A Powerful Tool to Enhance Bioactive Compounds." Applied Sciences 10, no. 20 (October 14, 2020): 7140. http://dx.doi.org/10.3390/app10207140.

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Lactobacillus plantarum ATCC 8014 was used to ferment quinoa flour, in order to evaluate its influence on the nutritional and rheological characteristics of both the sourdough and muffins. The quantification of carbohydrates and organic acids was carried out on a HPLC-RID system (high-performance liquid chromatography coupled with with refractive index detector), meanwhile HPLC-UV-VIS (high-performance liquid chromatography coupled with UV-VIS detector), AAS (Atomic absorption spectrophotometry), aluminum chloride colorimetric assay, Folin–Ciocalteu, and 1,1-Diphenyl-2-picrylhydrazyl radical scavenging activity (DPPH) methods were used to determine folic acid, minerals, flavonoids, total phenols, and radical scavenging activity, respectively. Two types of sourdough were used in this study: quinoa sourdough fermented with L. plantarum ATCC 8014 and quinoa sourdough spontaneous fermented. The first one influenced the chemical composition of muffins in terms of decreased content of carbohydrates, higher amounts of both organic acids and folic acid. Furthermore, higher amounts of flavonoids, total phenols and increased radical scavenging activity were recorded due to the use of Lactobacillus plantarum ATCC 8014 strain. These results indicate the positive effect of quinoa flour fermentation with the above strain and supports the use of controlled fermentation with lactic acid bacteria for the manufacturing of gluten free baked products.

23

Peng, Xinsheng, Baohong Li, Min Hu, Yahao Ling, Yuan Tian, Yanxing Zhou, and Yanfang Zhou. "Quantitative Analysis of Matrine in Liquid Crystalline Nanoparticles by HPLC." Journal of Analytical Methods in Chemistry 2014 (2014): 1–4. http://dx.doi.org/10.1155/2014/368682.

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A reversed-phase high-performance liquid chromatographic method has been developed to quantitatively determine matrine in liquid crystal nanoparticles. The chromatographic method is carried out using an isocratic system. The mobile phase was composed of methanol-PBS(pH6.8)-triethylamine (50 : 50 : 0.1%) with a flow rate of 1 mL/min with SPD-20A UV/vis detector and the detection wavelength was at 220 nm. The linearity of matrine is in the range of 1.6 to 200.0 μg/mL. The regression equation isy=10706x-2959(R2=1.0). The average recovery is 101.7%;RSD=2.22% (n=9). This method provides a simple and accurate strategy to determine matrine in liquid crystalline nanoparticle.

24

Sulaiman, Mohammad, Aishatu Maigari, Janefrances Ihedioha, Rasheed Lawal, Abdullahi Gimba, and Adamu Shuaibu. "Levels and health risk assessment of organochlorine pesticide residues in vegetables from Yamaltu area in Gombe, Nigeria." French-Ukrainian Journal of Chemistry 9, no. 1 (2021): 19–30. http://dx.doi.org/10.17721/fujcv9i1p19-30.

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The study determined the levels of organochlorine pesticides (OCPs) residues and assesses health risks linked with the consumption of vegetables cultivated in the Yamaltu area in Gombe, Nigeria. OCPs residues were solvent extracted and analyzed with a high performance liquid chromatography equipped with UV/VIS Detector. The mean concentrations of ten detected OCPs residues were almost all above the set limit of EU/WHOMRL. The estimated daily intake of OCPs from samples was below the acceptable daily intake, hazard index estimated were <1, indicated no probable non-carcinogenic health effect, while the carcinogenic health effect showed that children were more vulnerable for the consumption of the contaminated vegetables.

25

Safa, Saeed, Rasoul Sarraf-Mamoori, and Rouhollah Azimirad. "The Effects of Reduced Graphene Oxide (rGO) on ZnO Film UV-Detector." Advanced Materials Research 829 (November 2013): 577–82. http://dx.doi.org/10.4028/www.scientific.net/amr.829.577.

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In this work, pure and graphene incorporated ZnO thin films were prepared by solgel method on glass substrates and influence of graphene doping on the structural, electrical and optical properties of the films were studied. The results of Raman spectrum indicated the coexistence of ZnO and rGO in composite thin film. The FT-IR analysis of the composite sample showed that ZnO, ZnO-C heterojunction and C-C graphene skeletal peak are formed. The UV-Vis spectrum showed that both the transparency and band gap was partially decreased by graphene incorporation. The linear trend of I-V curve suggests an ohmic contact between ZnO and graphene nanosheets. In addition, the resistivity was decreased from 4.32×102 Ω.cm for pure ZnO film to 2.4×101 Ω.cm for composite film. The composite photodetector possessed a desirable signal to noise ratio and UV-sensitivity while the response time decreased to half of pure ZnO. The above results suggest that 0.225 wt.% rGO incorporation can improve the ultraviolet detection of ZnO thin film.

26

Huang, Liusheng, Patricia S. Lizak, Anura L. Jayewardene, Florence Marzan, Ming-Na Tina Lee, and Francesca T. Aweeka. "A Modified Method for Determination of Lumefantrine in Human Plasma by HPLC-UV and Combination of Protein Precipitation and Solid-Phase Extraction: Application to a Pharmacokinetic Study." Analytical Chemistry Insights 5 (January 2010): ACI.S4431. http://dx.doi.org/10.4137/aci.s4431.

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An HPLC-UV method was developed and validated for the determination of lumefantrine in human plasma. Lumefantrine and its internal standard halofantrine were extracted from plasma samples using protein precipitation with acetonitrile (0.2% perchloric acid) followed by solid-phase extraction with Hypersep C8 cartridges. Chromatographic separation was performed on a Zorbax SB-CN HPLC column (3.0 × 150 mm, 3.5 μm) with water/methanol (0.1% TFA) as the mobile phases in a gradient elution mode. Detection was performed using UV/vis detector at λ = 335 nm. The method showed to be linear over a range of 50-10,000 ng/mL with acceptable intra- and inter-day precision and accuracy. The mean recoveries were 88.2% for lumefatrine and 84.5% for the I.S. The internal standard halofantrine is readily available from commercial sources. This method was successfully applied to a pharmacokinetic interaction study between a first-line antimalarial combination (artemether—lumefantrine) and antiretroviral therapy.

27

Arayne, M. S., N. Sultana, and F. Hussain. "Validated RP-HPLC Method for Determination of Permethrin in Bulk and Topical Preparations Using UV-vis Detector." Journal of Chromatographic Science 49, no. 4 (April 1, 2011): 287–91. http://dx.doi.org/10.1093/chrsci/49.4.287.

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28

Karabudak, Engin, Wendel Wohlleben та Helmut Cölfen. "Investigation of β-carotene–gelatin composite particles with a multiwavelength UV/vis detector for the analytical ultracentrifuge". European Biophysics Journal 39, № 3 (26 лютого 2009): 397–403. http://dx.doi.org/10.1007/s00249-009-0412-6.

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29

Chuemere, Arthur N. "Gas Chromatography –Flame Ionization Detector, Phytochemical and Quality Control of Unripe Musa Sapientumthrough UV-Vis Spectrophotometric analysis." International Journal of Biomedical Investigation 4, no. 1 (June 30, 2021): 1–6. http://dx.doi.org/10.31531/2581-4745.1000129.

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Musa sapientum(banana) is widely consumed for its health benefits. Its pulp, peel, leaves, bark as well as whole fruit is used in reducing the risk of chronic diseases of clinical interests. This study aims to find out whether or not there are any distinctive phytochemical constituents present in unripe Musa sapientum peel, pulp and whole fruit hydromethanolic extract using GC-FID techniques and to demonstrate the importance of spectral data in contribution to quality control of its medicinal properties. The UV-VIS profile showed different peaks ranging from 200-900 nm with different absorption respectively. UV-VIS profile showed 9 peaks with three distinct peaks at 240 nm, 400 nm, and 700 nm for both pulp and its peel while 22 peaks with four at 220 nm, 290 nm, 550 nm and 600nm for whole fruit. GC-FID analysis provided characteristic peaks determining the presence and concentration of phytochemical compounds in peel, pulp and whole fruit. Three major phytoconstituents were found almost exclusively in peel, including, Isoflavones, lunamarine and sapogenin while proanthocyanidin and resveratrol were exclusively in its pulp. Spartein, phytates, tannins and isoflavones were absent in whole fruit. The concentration of flavone was minimal. In conclusion, the study justifies the nutritional and medicinal properties of the plant and also represents an additional support to the quality control of their fruit drugs. The presence of the distinctive phytochemicals may be mechanistic link for the specific-efficacy of their physio-pharmacologic and therapeutic activities. Ingested together, these study data suggests that peel, pulp or whole fruit supplementation may be a potential alternative to conventional treatment for various types of infirmities and may confer other potential industrial, nutritional and medicinal advantages.

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Yousif, Taqwa, and Asama Naje. "Enhancement of Photoconductive Detector Based on Carbon Nanotubes Decorated with Silver Nanoparticles by Adding Conductive Polymer." Iraqi Journal of Physics (IJP) 19, no. 50 (September 1, 2021): 84–93. http://dx.doi.org/10.30723/ijp.v19i50.682.

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In this work, wide band range photo detector operating in UV, Visible and IR was fabricated using carbon nanotubes (MWCNTs, SWCNTs) decorated with silver nanoparticles (Ag NPs). Silicon was used as a substrate to deposited CNTs/Ag NPs by the drop casting technique. Polyamide nylon polymer was used to coat CNTs/Ag NPs to enhance the photo-response of the detector. The electro-exploding wire technology was used to synthesize Ag NPs. Good dispersion of silver NPs achieved by a simple chemistry process on the surface of CNTs. The optical, structure and electrical characteristic of CNTs decorated with Ag NPs were characterized by X-Ray diffraction and Field Emission Scanning Electron Microscopy. X-ray diffraction patterns of Ag NPs exhibited 2θ values (38.1°,44.3°) corresponding to the Ag nanocrystal, while the XRD pattern of MWCNTs and SWCNTs /Ag NPs peaks appeared at 2θ = 26.2° corresponding to the (002) and at 2theta=44° which corresponds with miller indices (100) for CNTs and (200) for Ag NPs. The optical properties measured by UV-Vis. Spectroscopy. Broad and strong surface plasmon resonance (SPR) peak was detected at 420 nm, for Ag NPs. The absorption of CNTs/Ag NPs increased significantly from UV to near IR region (300-1000 nm). Ag NPs decorated CNTs without any impurities, according to field mission scanning electron microscopy examination, with typical particle sizes of (50-80nm) for Ag-NPs, 44nm for MWCNTs/Ag-NPs, and 30nm for SWCNTs/Ag NPs. ֹThe I-V characteristics at forward bias voltage (0.5-10) volt were studied. The figure of merits (responsivity, photocurrent gain, NEP and detectivity) after coating with polymer of the detector were measured in the dark and after illumination with UV LED (365 nm), Tungsten lamp (500-800 nm) and Laser diode (808 nm).

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Peng, Fei, Hong Hai Xue, Wei Cheng Chen, and Zhi Qun Li. "Investigation on Simultaneous Determination of Deltamethrin, Carbaryl, Microcystin-LR and Benzo[a]pyrene by Online SPE-HPLC Method." Advanced Materials Research 1073-1076 (December 2014): 575–78. http://dx.doi.org/10.4028/www.scientific.net/amr.1073-1076.575.

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In this paper, simultaneous analysis method for deltamethrin, carbaryl, microcystin-LR and benzo[a]pyrene in aqueous solution was established by online solid phase extraction (SPE)-HPLC technology. The target pollutants were enriched in SPE column, eluted by switching the six-way valve, separated by analytical column, and finally measured by UV-VIS Detector (UVD) and Fluorescence Detector (FLD). The results showed that online SPE-HPLC method was suitable for determination of these four organic pollutants. The correlation coefficient of the linear curve was all larger than 0.9990, and the detection limit and the limit of quantitation could also meet the Chinese standard method for drinking water (GB/T 5750-2006 and GB/T 3838-2006). This method achieved simultaneous online enrichment and efficient removal of substrate; avoided tedious manual pre-treatment process, saved the sample volume and processing time, and also had high recovery rate and sensitivity.

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Ocaya, R. O. "A Linear CCD Spectrometer Based on FPGA for Light-Source Characterization." Applied Mechanics and Materials 763 (May 2015): 120–25. http://dx.doi.org/10.4028/www.scientific.net/amm.763.120.

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We report on the implementation of a FPGA-based ultra-violet (UV), infra-red (IR) visible (Vis) CCD spectrometer using a linear CCD detector operating at room temperature. The host interface is high-speed USB for data exchange with high-level environments such as Visual Basic, MATLAB and LABVIEW. The high-resolution intensity versus wavelength output is 8-bit digitized for secondary processing using a semi-flash analogue-to-digital converter (ADC) capable of sustained sampling rates of 20Mb/s.

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Ahmed, Hala Moustafa. "Biophysical and Characterizations of Silver Nanoparticles used as Salmonella typhi Detector." International Journal of Applied Sciences and Biotechnology 2, no. 4 (December 25, 2014): 510–15. http://dx.doi.org/10.3126/ijasbt.v2i4.11127.

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The present study mainly focuses of combined action of Nepali hog plum as well as citrate synthesized silver nanoparticles (AgNPs) and Amikacin, as an antibiotic. The synergistic actions of citrate stabilized silver nanoparticles (AgNPs with chem) were compared with that of Nepali hog plum Choerospondia saxillaris (Lapsi) synthesized silver nanoparticles (AgNPs with plant), together with action of antibiotic onselected bacterial strains of Salmonella typhi. The synthesized AgNPs were characterized through UV-Vis spectroscopy, Transmission electronmicroscopy and X-ray diffraction technique. The size of the synthesized silver nanoparticles was measured by Transmission Electron Microscope (TEM) and X-ray diffraction (XRD).DOI: http://dx.doi.org/10.3126/ijasbt.v2i4.11127 Int J Appl Sci Biotechnol, Vol. 2(4): 510-515

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Nguyen Thanh, Dat, Hong Hanh Nguyen Thi, Thu Dam Thi, Thuy Chu Thi, and Nuong Hoang Thi. "Determination of rutin content in sophora japonia L. Extracts used as raw material in supplements by high performance liquid chromatography." Heavy metals and arsenic concentrations in water, agricultural soil, and rice in Ngan Son district, Bac Kan province, Vietnam 2, no. 3 (September 10, 2019): 51–55. http://dx.doi.org/10.47866/2615-9252/vjfc.80.

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An HPLC-UV method was proposed in order to determine Rutin in Sophora japonica L. extract samples (3 samples extracted with 30% ethanol, 3 samples extracted with 70% ethanol and 3 samples extracted with water). The chromatographic conditions were: Agilent Zorbax Eclipse XDB C18 Column (150 x 4.6 mm, 5 µm); UV-Vis detector (257 nm); mobile phase: a mixture of methanol and 1% acetic acid solution (40:60, v/v). The linear range was of 4.97 - 298.47µg/mL; the LOQ was of 0.205 µg/mL and the accuracy was within 99.87% - 102.3%. The method was proved to be suitable for the determination of Rutin in Sophora japonica L. extracts. Rutin content in samples varied from 30.14% to 38.67%.

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Zhao, Wen, Chao Hao Hu, Ran Chen, Feng Zheng Lv, Yan Zhong, and Huai Ying Zhou. "Synthesis and Photocatalytic Activity of Ag-Doped BiVO₄." Advanced Materials Research 734-737 (August 2013): 2204–9. http://dx.doi.org/10.4028/www.scientific.net/amr.734-737.2204.

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Ag-doped BiVO4 semiconductor photocatalysts were synthesized via the one-step hydrothermal method. The microstructure and morphology of catalysts were characterized by using X-ray diffraction, Scanning electron microscopy, and Energy dispersive X-ray detector (EDS) and photocatalytic activities of BiVO4 catalysts with and without Ag doping were evaluated by degrading methylene blue (MB) under visible-light irradiation. UV-Vis absorption spectra were measured to evaulate the photocatalytic activity of the as-synthesized catalysts. The results suggested that Ag-doped BiVO4 with larger rod-like particle size but better crystallnity has the stronger UV absorption. In comparison with pure BiVO4, degradation rate of MB was increased about 18% in Ag-doped BiVO4 with the Ag+ dopant concentration of 15 mol%.

36

Li, Min, Liu-Yin Fan, Wei Zhang, Ji Sun, and Cheng-Xi Cao. "Quantitative analysis of lovastatin in capsule of Chinese medicine Monascus by capillary zone electrophoresis with UV–vis detector." Journal of Pharmaceutical and Biomedical Analysis 43, no. 1 (January 2007): 387–92. http://dx.doi.org/10.1016/j.jpba.2006.07.003.

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Beek, Wilhelmus M. J., and Marinus M. L. Aerts. "Determination of furazolidone residues in eggs by HPLC followed by confirmation with a diode-array UV/Vis detector." Zeitschrift f�r Lebensmittel-Untersuchung und -Forschung 180, no. 3 (March 1985): 211–14. http://dx.doi.org/10.1007/bf01027267.

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Hoehl, Melanie M., James B. Macarthur, Peter A. Sims, Hongshen Ma, and Alexander H. Slocum. "Robust and economical multi-sample, multi-wavelength UV/vis absorption and fluorescence detector for biological and chemical contamination." AIP Advances 2, no. 3 (September 2012): 032110. http://dx.doi.org/10.1063/1.4738962.

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Vetter, Florian Lukas, Steffen Zobel-Roos, and Jochen Strube. "PAT for Continuous Chromatography Integrated into Continuous Manufacturing of Biologics towards Autonomous Operation." Processes 9, no. 3 (March 6, 2021): 472. http://dx.doi.org/10.3390/pr9030472.

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This study proposes a reliable inline PAT concept for the simultaneous monitoring of different product components after chromatography. The feed for purification consisted of four main components, IgG monomer, dimer, and two lower molecular weight components of 4.4 kDa and 1 kDa molecular weight. The proposed measurement setup consists of a UV–VIS diode-array detector and a fluorescence detector. Applying this system, a R2 of 0.93 for the target component, a R2 of 0.67 for the dimer, a R2 of 0.91 for the first side component and a R2 of 0.93 for the second side component is achieved. Root mean square error for IgG monomer was 0.027 g/L, for dimer 0.0047 g/L, for side component 1 0.016 g/L and for the side component 2 0.014 g/L. The proposed measurement concept tracked component concentration reliably down to 0.05 g/L. Zero-point fluctuations were kept within a standard deviation of 0.018 g/L for samples with no IgG concentration but with side components present, allowing a reliable detection of the target component. The main reason inline concentration measurements have not been established yet, is the false-positive measurement of target components when side components are present. This problem was eliminated using the combination of fluorescence and UV–VIS data for the test system. The use of this measurement system is simulated for the test system, allowing an automatic fraction cut at 0.05 g/L. In this simulation a consistent yield of >99% was achieved. Process disturbances for processed feed volume, feed purity and feed IgG concentration can be compensated with this setup. Compared to a timed process control, yield can be increased by up to 12.5%, if unexpected process disturbances occur.

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Shaikh, Zaheer, Abdul Ahad, Showkat Patel, and Maqdoom Farooqui. "Development & Validation of HPLC method for simultaneous estimation of Drotaverine & Omeprazole." International Journal of ChemTech Research 13, no. 1 (2020): 1–10. http://dx.doi.org/10.20902/ijctr.2019.130101.

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A simple and accurate method was developed for simultaneous estimation of Drotaverine & Omeprazole. The chromatography parameters includes stainless steel column Develosil ODS HG-5 RP C18, 5m, 15cmx4.6mm i.d and acetonitrile: potassium dihydrogen phosphate buffer (0.02M, pH 3.0) (55:45v/v) as mobile phase at a flow rate (1.0 ml/minute). The determinations were performed using UV-Vis detector set at 273 nm. The developed HPLC method showed specificity and selectivity with good precision and accuracy, which makes it very suitable for quantification of Drotaverine & Omeprazole.

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Rusnaenah, Andi, Muhammad Zakir, and Prastawa Budi. "Biosintesis Nanopartikel Perak menggunakan Ekstrak Daun Ketapang, Modifikasi dengan Asam p-kumarat untuk Aplikasi Deteksi Melamin." Indo. J. Chem. Res. 4, no. 2 (January 31, 2017): 367–72. http://dx.doi.org/10.30598//ijcr.2017.4-and.

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Biosynthesis of silver nanoparticles (AgNPs) using ketapang leaf extract, modification with p-coumaric acid for detecting melamine has conducted. This research aimed to synthesize AgNPs via bio-reduction method using ketapang leaf extract followed by modification with p-coumaric acid (APK), and evaluating its application detecting melamine. The AgNPs were characterized through ultraviolet-visible absorption spectroscopy (UV-Vis) and X-ray diffraction (XRD). Observation suggested that an increase of incubation time had affected its surface Plasmon resonance trend. Further analysis of crystallite via XRD suggested that nanoparticle size at 43 nm estimated using Debye-Scherer, within the form of unit cells is cubic. The performance of product as melamine detector suggested that the AgNPs-APK had detected melamine in range of concentration from 0.1 to 1000 ppm.

42

Burian, Max, Benedetta Marmiroli, Andrea Radeticchio, Christian Morello, Denys Naumenko, Giorgio Biasiol, and Heinz Amenitsch. "Picosecond pump–probe X-ray scattering at the Elettra SAXS beamline." Journal of Synchrotron Radiation 27, no. 1 (January 1, 2020): 51–59. http://dx.doi.org/10.1107/s1600577519015728.

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A new setup for picosecond pump–probe X-ray scattering at the Austrian SAXS beamline at Elettra-Sincrotrone Trieste is presented. A high-power/high-repetion-rate laser has been installed on-site, delivering UV/VIS/IR femtosecond-pulses in-sync with the storage ring. Data acquisition is achieved by gating a multi-panel detector, capable of discriminating the single X-ray pulse in the dark-gap of the Elettra hybrid filling mode. Specific aspects of laser- and detection-synchronization, on-line beam steering as well protocols for spatial and temporal overlap of laser and X-ray beam are also described. The capabilities of the setup are demonstrated by studying transient heat-transfer in an In/Al/GaAs superlattice structure and results are confirmed by theoretical calculations.

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Le, Dinh Chi, Thi Duyen Ngo, and Thi Huong Hoa Le. "Simultaneous Assay of Dexchlorpheniramine Maleate, Betamethasone, and Sodium Benzoate in Syrup by a Reliable and Robust HPLC Method." Journal of Analytical Methods in Chemistry 2019 (November 29, 2019): 1–10. http://dx.doi.org/10.1155/2019/2952075.

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The simultaneous determination of betamethasone, dexchlorpheniramine maleate, and sodium benzoate in pharmaceutical syrup was done by using a simple validated HPLC method. The chromatographic separation of the three analytes was done in a C18 column maintained at 25°C, using a mixture of acetonitrile and 0.02 M phosphate buffer solution pH 2.70 (35 : 65, v : v) as mobile phase. The isocratic elution was chosen with total flow rate of mobile phase maintained at 1.0 mL per minute. The analytes were detected by a UV-Vis detector set at 254 nm. Injection volume was set at 50 μl. The method was fully validated in terms of specificity, linearity, precision, accuracy, and robustness according to requirements of current guidelines and was proven to be suitable for the intended application.

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Cahyono, Bambang, Christiana Suci Prihatini, Meiny Suzery, and Damar Nurwahyu Bima. "Penentuan Aktivitas Antioksidan Senyawa Kuersetin dan Ekstrak Lengkuas Menggunakan HPLC dan UV-Vis." ALCHEMY 8, no. 2 (January 30, 2021): 24–32. http://dx.doi.org/10.18860/al.v8i2.10594.

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The radical scavenging activity of 1,1-diphenyl-2-picrylhidrazyl (DPPH) is generally carried out using a spectrophotometric method. In this study, the value of the antioxidant activity was compared to the HPLC method. Samples used were pure quercetin and extracts of red galangal (Alpinia purpurata) and white galangal (Alpinia galanga). Analysis of antioxidant activity using a UV/Vis spectrophotometer was carried out at a wavelength of 515 nm. Analysis by HPLC method was carried out using an inverse phase with a UV/Vis detector at 515 nm. The results showed that the radical scavenging activity (IC50) of the pure quercetin produced was nearly the same value for the spectrophotometric method (16.24 ppm) dan the HPLC method (15.24 ppm). Even though, the antioxidant activity of pure quercetin was different from the extract. The red galangal extract gave IC50 of 488.43±1.13 ppm (spectrophotometric method) and IC50 of 68.12±10.19 ppm (HPLC method). The radical scavenging activity (IC50) of white galangal extract using the spectrophotometric method and HPLC method was 462.47±2.98 and 62.17±3.87 ppm, respectively. The allegation of other molecular interference in the radical reduction of the extract resulted in a conclusion that the HPLC is better than the spectrophotometric method for determining antoxidant activity of extract sample. Keywords: Antioxidant, Alpinia purpurata, Alpinia galanga, DPPH Aktivitas peredaman radikal 1,1-diphenyl-2-picrylhidrazyl (DPPH) pada umumnya dilakukan menggunakan metode spektrofotometer. Dalam penelitian ini, nilai aktivitas antioksidan tersebut telah dibandingkan dengan metode HPLC. Sampel ujinya adalah senyawa kursetin murni dan ekstrak lengkuas merah (Alpinia purpurata) dan lengkuas putih (Alpinia galanga). Analisis aktivitas antioksidan dengan spektrofotometer UV/Vis dilakukan pada panjang gelombang 515 nm. Analisis dengan metode HPLC dilakukan menggunakan fasa inverse dengan detektor UV/Vis pada 515 nm. Hasil penelitian menunjukkan bahwa aktivitas peredaman radikal senyawa murni kuersetin menghasilkan nilai yang hampir sama untuk kedua metode yaitu IC50 sebesar 17,05 ppm untuk metode spektrofotometer dan IC50 sebesar 15,74 ppm untuk metode HPLC. Akan tetapi, nilai aktivitas antioksidan kuersetin jauh berbeda untuk ekstrak. Ekstrak lengkuas merah memberikan IC50 sebesar 488,43±1,13 ppm (metode spektrofotometer) dan 68,12±10,19 ppm (metode HPLC). Aktivitas peredaman radikal ekstrak lengkuas putih dengan metode spektrofotometer dan HPLC dengan IC50 sebesar 462,89±5,38 dan 62,17±3,87 ppm, berturut-turut. Dugaan adanya interferensi molekul lain dalam analisis peredaman radikal terhadap ekstrak ini menghasilkan suatu kesimpulan bahwa metode HPLC lebih baik digunakan dalam analisis antioksidan dibandingkan metode spektrofotometer untuk sampel berupa ekstrak. Kata kunci: Antioksidan, Alpinia purpurata, Alpinia galanga, DPPH

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Sun, Hai Hong, Xiao Mei Mo, and Ye Miao Qian. "Comparison of HPLC and Spectrophotometry Methods on Quantitative Determination of Formaldehyde in Water Based Coatings." Advanced Materials Research 816-817 (September 2013): 433–38. http://dx.doi.org/10.4028/www.scientific.net/amr.816-817.433.

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To explore and compare the reliability of the quantitative determination of formaldehyde content of water based coatings, the high performance liquid chromatography (HPLC) after derivatization to 2.4-dinitrophenylhydazone and UV-VIS spectrophotometry were studied, respectively. HPLC was performed on a C18 column with acetonitrile/water (65/35, V/V) as mobile phase at a flow rate of 1.0 mL/min, and analyses was detected using Photodode Array Detector (DAD) at the wavelength of 360 nm. And formaldehyde was determined with spectrophotometry at 435nm. The result showed the standard curve of formaldehyde by the HPLC method was linear in the range of 0.1-5.0 mg/L (R2=0.9998). The detection limit was 0.96mg/kg, recoveries were ranging from 96.2% to 101.3%. The linear range of formaldehyde by the spectrophotometric method was 0.1～5.0 mg/L (R2=0.9995), and the detection limit was 5.93mg/kg, recoveries were ranging from 98.5% to 105.3%. In conclusion, both the two methods can be used for quantitative analysis of formaldehyde in water based coatings, and the major advantages of HPLC are quick, simple and sensitive.

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Maigari, A. U., M. B. Sulaiman, M. Buhari, and A. O. Abdullahi. "Pesticide residues in selected vegetables from Gombe markets, Gombe State, Nigeria: assessing the health impact." Ife Journal of Science 23, no. 1 (May 3, 2021): 77–87. http://dx.doi.org/10.4314/ijs.v23i1.8.

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The study determined the content of pesticide residues in vegetables (cabbage, lettuce, calyces, and tiger nut), obtained from markets in Gombe, Nigeria. Health risk parameters were also determined to evaluate the health risk associated with their consumption. A total of 72 samples (cabbage, lettuce, calyces and tiger nut) were analyzed using high performance liquid chromatography with UV/VIS Detector (HPLC-UV/VIS). A total of 18 pesticide residues were detected: nine organochlorines (OCs), five organophosphates (OPs), and four pyrethroids (PYs). The residual contents of nine OCs ranged from 0.00 to 0.098 μg/kg and found in 61.87%, 60.99%, 63.69%, and 63.89% of cabbage, lettuce, calyces and tiger nut samples respectively, five OPs with concentrations ranging from 0.00 to 0.043 μg/kg were found in 22.69%, 21.89%, 19.49% and 22.21% of cabbage, lettuce, calyces and tiger nut samples respectively. In similar order, four PYs with concentrations that ranged from 0.00 to 0.046 μg/kg were found in 15.44%, 17.04%, 16.82% and 13.89% of the vegetables. Themean estimated daily intake of pesticides in the studied samples was lower than that of acceptable daily intakes. The hazard index obtained was less than one, indicating no probable adverse health effect on both children and adult consumers. However, monitoring and continuous stringent regulation should be imposed with regard to the usage of pesticides in vegetables, and other food stuff for public health protection. Keywords: Hazard Index, Health risk, Nut, Pesticide residues, Vegetables

47

Chen, Ran, Chao Hao Hu, Shuai Wei, Jin Hong Xia, Jian Cui, and Huai Ying Zhou. "Synthesis and Activity of Ag-Doped Bi₂WO₆ Photocatalysts." Materials Science Forum 743-744 (January 2013): 560–66. http://dx.doi.org/10.4028/www.scientific.net/msf.743-744.560.

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Ag-doped Bi2WO6 photocatalysts were synthesized by hydrothermal method using from Bi (NO)3·5H2O, NH4VO3, and AgNO3 and further characterized by X-ray diffraction, Scanning electron microscopy, Energy dispersive X-ray detector (EDS) and UV-Vis diffusion reflectance spectra techniques. The photocatalytic activity of Ag-doped Bi2WO6 photocatalysts was evaluated by degrading RhB (10 mg/L) under visible light irradiation (λ > 420 nm). The results showed that in comparison with pure Bi2WO6 the photocatalytic activity of Ag-doped composite photocatalysts was improved significantly, and the degradation rate of RhB was increased about 26% when the Ag+ dopant concentration was 15%.

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Visani, Valeria, Sara Regina Ribeiro Carneiro De Barros, Heronides Adonias Dantas Filho, Luciano Farias De Almeida, Ricardo Alexandre Cavalcanti De Lima, Wallace Duarte Fragoso, Teresa Cristina Bezerra Saldanha, and Mário César Ugulino Araújo. "Flow-batch analyser for preparation of calibration standard mixtures in simultaneous multicomponent spectrometric analysis." Eclética Química Journal 34, no. 2 (January 24, 2018): 37. http://dx.doi.org/10.26850/1678-4618eqj.v34.2.2009.p37-47.

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The application of multivariate calibration techniques to multicomponent analysis by UV-VIS molecular absorption spectrometry is a powerful tool for simultaneous determination of several chemical species. However, when this methodology is accomplished manually, it is slow and laborious, consumes high amounts of reagents and samples, is susceptible to contaminations and presents a high operational cost. To overcome these drawbacks, a flow-batch analyser is proposed in this work. This analyser was developed for automatic preparation of standard calibration and test (or validation) mixtures. It was applied to the simultaneous determination of Cu2+, Mn2+ and Zn2+ in polyvitaminic and polymineral pharmaceutical formulations, using 4-(2-piridilazo) resorcinol as reagent and a UV-VIS spectrophotometer with a photodiode array detector. The results obtained with the proposed system are in good agreement with those obtained by flame atomic absorption spectrometry, which was employed as reference method. With the proposed analyser, the preparation of calibration and test mixtures can be accomplished about four hours, while the manual procedure requires at least two days. Moreover, it consumes smaller amounts of reagents and samples than the manual procedure. After the preparation of calibration and test mixtures, 60 samples h-1 can be carried out with the proposed flow-batch analyser.

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Elamathi, P., Murali Krishna Kolli, and G. Chandrasekar. "Catalytic Oxidation of Vanillyl Alcohol Using FeMCM-41 Nanoporous Tubular Reactor." International Journal of Nanoscience 17, no. 01n02 (October 12, 2017): 1760010. http://dx.doi.org/10.1142/s0219581x17600109.

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Iron containing nanoporous MCM-41 (FeMCM-41) with different Si/Fe ratios of 50, 100 and 150 was synthesized by hydrothermal synthesis process. The materials obtained from hydrothermal synthesis were characterized by various physico chemical techniques such as XRD, N2 adsorption, DR UV-vis, EPR and FTIR spectroscopy. XRD analyses of FeMCM-41 materials confirmed the presence of well-ordered crystalline structure. N2 isotherm of FeMCM-41 materials showed type IV adsorption isotherm. EPR and DR UV-vis analysis of FeMCM-41 samples indicates the presence of high tetrahedral coordination at the Si/Fe ratios of 100 and 150. The catalytic performance of FeMCM-41 nano tubular reactor was tested in the liquid phase oxidation of vanillyl alcohol into vanillin using H2O2 (50[Formula: see text]wt% in water). The reaction products were analyzed by gas chromatography in DB-5 capillary column with flame ionization detector. The products were confirmed by 1H NMR, [Formula: see text]C NMR and LC-Mass spectroscopy. The maximum conversion of vanillyl alcohol (85%) and selectivity towards vanillin (82%) were observed using the catalyst FeMCM-41(100) in 30[Formula: see text]min at 60[Formula: see text]C. The influence of reaction temperature, reaction time, reactants molar ratio, Si/Fe ratio and amount of catalyst were investigated.

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Hitsmi, Marti, Mochamad Lutfi Firdaus, and Nurhamidah Nurhamidah. "PENGEMBANGAN METODE CITRA DIGITAL BERBASIS APLIKASI ANDROID UNTUK ANALISIS ION LOGAM Cr(VI)." Alotrop 2, no. 2 (May 21, 2019): 117–24. http://dx.doi.org/10.33369/atp.v4i2.13835.

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The presence of heavy metals in the environment can be a serious problem because it is harmful to human health. One of the heavy metal ions that pollute the environment is the Cr6+ metal ion. The usual tool used to analyze metal ions is Cr6+ is the Atomic Absorption Spectrometry (AAS) and Inductively Couple Plasma (ICP) which are very expensive and require trained personnel. The purpose of this study was to design a simple detector for Cr6+ metal ions as an alternative to conventional methods using AAS and ICP. The detection tool was developed using the android-based digital image method with SLR data analysis techniques obtained from the reaction of the metal ion complex Cr6 + with the compound dhypenilcarbazida (DPC). The parameters of the tool measured were accuracy, selectivity and sensitivity with the reaction of DPC compounds as complexes. The comparison level of this method is the complex method with DPC using a UV-Vis spectrophotometer. This research was carried out in the Chemistry Laboratory FKIP UNIB in November 2018 until March 2019. The implementation of tool parameters was tested to samples of aquatic environments in Bengkulu City, namely PDAM Kota Bengkulu water, tap water of FKIP UNIB Dean, Lake UNIB water, Sungai Hitam water and water Pantai Panjang. The results showed that the detection of Cr6+ metal ions made by the android-based digital image method had better accuracy, selectivity and sensitivity than conventional methods. The DPC is selective for Cr6 + metal ions with a change in color from clear to violet, at a wavelength of 540 nm. Accuracy was checked using a UV-Vis spectrophotometer with 99% accurate results. After that, test sensitivity to Cr6 + metal ions. using the android application method generates a Limit of Detection (LOD) of 6.7 ppb. The detector that was developed was applied to water samples in the city of Bengkulu, it turned out that all of the water samples showed that the levels of Cr6+ metal ions were still below the threshold determined by the Minister of Health Regulation, so it was still safe to use in everyday life.

Статті в журналах з теми "UV-VIS detector"

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