Journal articles: 'Spectrophotometry'

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Morawski, Roman Z. "Measurement Data Processing in Spectrophotometric Analysers of Food." Metrology and Measurement Systems 19, no. 4 (December 1, 2012): 623–52. http://dx.doi.org/10.2478/v10178-012-0056-1.

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Abstract Spectrometry, especially spectrophotometry, is getting more and more often the method of choice not only in laboratory analysis of (bio)chemical substances, but also in the off-laboratory identification and testing of physical properties of various products, in particular - of various organic mixtures including food products and ingredients. Specialised spectrophotometers, called spectrophotometric analysers, are designed for such applications. This paper is on the state of the art in the domain of data processing in spectrophotometric analysers of food (including beverages). The following issues are covered: methodological background of food analysis, physical and metrological principles of spectrophotometry, the role of measurement data processing in spectrophotometry. General considerations are illustrated with examples, predominantly related to wine and olive oil analysis.

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Andulaai, Arlina Mayharty, Ruslan Ruslan, Hardi Ys., and Dwi Juli Puspitasari. "STUDI PERBANDINGAN ANALISIS VITAMIN E MINYAK SAWIT MERAH TERSAPONIFIKASI ANTARA METODE SPEKTROFOTOMETRI UV-VIS DAN KCKT." KOVALEN 3, no. 1 (April 30, 2017): 50. http://dx.doi.org/10.22487/j24775398.2017.v3.i1.8233.

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A research about a comparative study of spectrophotometry UV-Vis and HPLC method for the analysis of vitamin E in saponified red palm oil has been done. This research aims to compare the results of analysis using Spectrophotometer UV - Vis and HPLC to determine the concentration of vitamin E in red palm oil previously saponified and extracted. HPLC analysis was carried out using an RP-18 column and mobile phase composed a methanol and water ( 86:14 ), with a flow rate of 1 ml/min and UV detection at 290 nm. For the Spectrophotometric UV-Vis analysis, hexane was used as a solvent and the wavelength at 298,5 nm was selected for the detection. The results are the concentration of vitamin E using spectrophotometric and HPLC method was respectively 104.5 ppm and 127 ppm.Keyword: Vitamin E, Red Palm Oil, saponification, extraction, spectrophotometry Ultra Violet -Visible, High Performance Liquid Chromatography

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Jeffers, S., and T. Stiff. "Stellar spectrophotometry with a microcomputer based, intensified, silicon vidicon." Symposium - International Astronomical Union 118 (1986): 453–55. http://dx.doi.org/10.1017/s0074180900151903.

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We have developed several detector systems for use in observational astronomy. These include a rapid scanning spectrometer (Jeffers and Weller, 1973), a rapid chopping spectrophotometer (Stiff and Jeffers, 1978) and an intensified, silicon vidicon detector for use either for spectrophotometry (Jeffers, Stiff and Weller, 1983) or direct imaging (Jeffers, 1982). These detector systems have been used for rapid variability studies of emission line strengths and profiles in Wolf-Rayet and Of stars (Weller and Jeffers, 1979; Jeffers, Stiff and Weller, 1985) and for low dispersion spectrophotometry of these stars (Jeffers and Weller, 1985). Here we report on the spectrophotometric performance of the intensified, silicon vidicon detector (RCA 4804H) when used with a low dispersion spectrograph.

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Tsecheev, Arthur T., and Yurii N. Karpenko. "Application of UV spectrophotometry and reversed-phase HPLC to determine the ionization constant of a new biologically active compound." Aspirantskiy Vestnik Povolzhiya 23, no. 2 (June 16, 2023): 60–65. http://dx.doi.org/10.55531/2072-2354.2023.23.2.60-65.

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Aim to determine the ionization constant (pKa) of the biologically active compound 2-ABPPC by UV spectrophotometry and high performance liquid chromatography (HPLC). Material and methods. The object of the study was the substance 2-ABPPC (2-amino-1-(4-bromophenyl)-5-(3,3-dimethyl-2-oxobutylidene)-4-oxo-4,5-dihydro-1H-pyrrole-3- carboxamide). The methods of UV spectrophotometry and high performance liquid chromatography were used to determine the ionization constant. The spectrophotometric analysis was carried out on a Shimadzu UV-1800 spectrophotometer. The chromatographic determination of the pKa value was carried out on an LC-20 Prominence liquid chromatograph (Shimadzu) using a Zorbax Extend-C18 reversed-phase column. Results. In the course of study, it was found that 2-ABPPC has one pKa value. When using two different methods to estimate the ionization constant, the comparable results were obtained: 7.64 (UV spectrophotometry method) and 7.40 (reversed phase HPLC method).

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Versmessen, Nick, Leen Van Simaey, Abel Abera Negash, Marjolein Vandekerckhove, Paco Hulpiau, Mario Vaneechoutte, and Piet Cools. "Comparison of DeNovix, NanoDrop and Qubit for DNA quantification and impurity detection of bacterial DNA extracts." PLOS ONE 19, no. 6 (June 17, 2024): e0305650. http://dx.doi.org/10.1371/journal.pone.0305650.

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Accurate DNA quantification is key for downstream application including library preparations for whole genome sequencing (WGS) and the quantification of standards for quantitative PCR. Two commonly used technologies for nucleic acid quantification are based on spectrometry, such as NanoDrop, and fluorometry, such as Qubit. The DS–11+ Series spectrophotometer/fluorometer (DeNovix) is a UV spectrophotometry-based instrument and is a relatively new spectrophotometric method but has not yet been compared to established platforms. Here, we compared three DNA quantification platforms, including two UV spectrophotometry-based techniques (DeNovix and NanoDrop) and one fluorometry-based approach (Qubit). We used genomic prokaryotic DNA extracted from Streptococcus pneumoniae using a Roche DNA extraction kit. We also evaluated purity assessment and effect of a single freeze-thaw cycle. Spectrophotometry-based methods reported 3 to 4-fold higher mean DNA concentrations compared to Qubit, both before and after freezing. The ratio of DNA concentrations assessed by spectrophotometry on the one hand, and Qubit on the other hand, was function of the A260/280. In case DNA was pure (A260/280 between 1.7 and 2.0), the ratio DeNovix or Nanodrop vs. Qubit was close or equal to 2, while this ratio showed an incline for DNA with increasing A260/280 values > 2.0. The A260/280 and A260/230 purity ratios exhibited negligible variation across spectrophotometric methods and freezing conditions. The comparison of DNA concentrations from before and after freezing revealed no statistically significant disparities for each technique. DeNovix exhibited the highest Spearman correlation coefficient (0.999), followed by NanoDrop (0.81), and Qubit (0.77). In summary, there is no difference between DeNovix and NanoDrop in estimated gDNA concentrations of S. pneumoniae, and the spectrophotometry methods estimated close or equal to 2 times higher concentrations compared to Qubit for pure DNA.

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Wahyuningtyas, Fatma Anggoro, Alda Safitri Maria Ulfa, and Dewi Astri Rahmawati. "Identification of antibiotic by chromatographic and spectrophotometric methods – A Review." Asian Journal of Analytical Chemistry 1, no. 1 (June 8, 2023): 18–24. http://dx.doi.org/10.53866/ajac.v1i1.270.

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The purpose of this article to review the validation and content of antibiotics using various chromatographic and spectrophotometric methods. This review article used five analytical methods on antibiotics, namely high-performance liquid chromatography (HPLC), Fourier transform infrared (FTIR), gas chromatography (GC), ultraviolet-visible (UV-Vis) spectrophotometer and liquid chromatography/mass spectrophotometer (LC/MS) methods. Antibiotics are the most widely used drugs for infections caused by bacteria. Based on a review of several studies related to antibiotic analysis, the general techniques applied are HPLC, FTIR, GC, UV-Vis Spectrophotometry, and LC-MS. Analysis of this antibiotic is a massive challenge due to its sensitivity and instability to various conditions.

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Vavřičková, Lenka, Martin Kapitán, and Eliška Charlotte Wurfel. "Are Digital Methods Sufficiently Successful in Colour Determination for Monolithic All-Ceramic Crowns?" Acta Medica (Hradec Kralove, Czech Republic) 65, no. 3 (2022): 99–104. http://dx.doi.org/10.14712/18059694.2022.25.

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Objective: The aim of this study was to compare the visual assessment of tooth shade with the measurement using intraoral scanner (IOS) and spectrophotometer devices. Methodology: The colour for a single unit implant supported crown was measured visually, using IOS, and spectrophotometer. The results of the digital methods were compared with the visual measurement. Results: A complete colour match with the visual measurement was in 42.9% of cases for IOS, and in 33.3% of cases for spectrophotometry. The match in the colour value, hue, and chroma were in 61.9%, 95.2%, and 66.7% of cases, respectively, for the IOS; and in 61.9%, 61.9%, and 66.7% of cases, respectively, for the spectrophotometry. The differences between the IOS and spectrophotometry were not statistically significant. Conclusions: The most reliable method for tooth colour selection is the visual measurement by an experienced dentist. IOS and spectrophotometer can be used as an alternative method, however in both cases they should be verified using visual measurement.

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Kumari, Ankita, Kanika Kambo, and Shahid ul Islam. "Exploring the Utilization and Application of Mass Spectrophotometry across Various Fields within Clinical Laboratory Science." Middle East Journal of Applied Science & Technology 06, no. 04 (2023): 98–106. http://dx.doi.org/10.46431/mejast.2023.6408.

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This review paper provides a thorough examination of the use of Mass Spectrophotometry in clinical laboratory science. Mass spectroscopy is a strong analytical tool that has transformed clinical diagnostics and research. This paper looks at how mass spectrometers are used in clinical laboratory science, drug testing and monitoring, newborn screening, toxicology clinical diagnostics, biomarker identification, and proteomics research. The report also examines the benefits and drawbacks of using a mass spectrophotometer in clinical laboratory settings. The findings demonstrate the importance of mass spectrophotometers in enhancing patient care, disease detection, and scientific understanding in the clinical laboratory sector.

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Vreman, H. J., R. B. Ronquillo, R. L. Ariagno, H. C. Schwartz, and D. K. Stevenson. "Interference of fetal hemoglobin with the spectrophotometric measurement of carboxyhemoglobin." Clinical Chemistry 34, no. 5 (May 1, 1988): 975–77. http://dx.doi.org/10.1093/clinchem/34.5.975.

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Abstract We measured the concentration of carboxyhemoglobin (HbCO) in blood samples from 32 neonates by spectrophotometry (IL282 CO-Oximeter) and gas chromatography, finding a strong positive correlation (r = 0.89) between the concentration of fetal hemoglobin (Hb F) and HbCO as measured by spectrophotometry, but not by gas chromatography. Thus, Hb F interferes with the determination of HbCO by spectrophotometric techniques by falsely increasing apparent HbCO in direct proportion to Hb F. We conclude that, when Hb F is known or suspected to be present, blood HbCO cannot be reliably determined by methods based on spectrophotometry.

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Tucker, M. A., B. J. Shappee, M. E. Huber, A. V. Payne, A. Do, J. T. Hinkle, T. de Jaeger, et al. "The Spectroscopic Classification of Astronomical Transients (SCAT) Survey: Overview, Pipeline Description, Initial Results, and Future Plans." Publications of the Astronomical Society of the Pacific 134, no. 1042 (December 1, 2022): 124502. http://dx.doi.org/10.1088/1538-3873/aca719.

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Abstract We present the Spectroscopic Classification of Astronomical Transients (SCAT) survey, which is dedicated to spectrophotometric observations of transient objects such as supernovae and tidal disruption events. SCAT uses the SuperNova Integral-Field Spectrograph (SNIFS) on the University of Hawai’i 2.2 m (UH2.2m) telescope. SNIFS was designed specifically for accurate transient spectrophotometry, including absolute flux calibration and host-galaxy removal. We describe the data reduction and calibration pipeline including spectral extraction, telluric correction, atmospheric characterization, nightly photometricity, and spectrophotometric precision. We achieve ≲5% spectrophotometry across the full optical wavelength range (3500–9000 Å) under photometric conditions. The inclusion of photometry from the SNIFS multi-filter mosaic imager allows for decent spectrophotometric calibration (10%–20%) even under unfavorable weather/atmospheric conditions. SCAT obtained ≈640 spectra of transients over the first 3 yr of operations, including supernovae of all types, active galactic nuclei, cataclysmic variables, and rare transients such as superluminous supernovae and tidal disruption events. These observations will provide the community with benchmark spectrophotometry to constrain the next generation of hydrodynamic and radiative transfer models.

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Nur, Arfiani, Hajrah Hajrah, Asriani Ilyas, Aisyah Aisyah, and Maria Cecilia Lezama Escalante. "Determination and Characterization of Lycopene Compounds from N-Hexane Fraction of Tomato Fruit (Solanum Lycopersocum Grandyfolium) by using Fourier Transform Infrared and UV-Vis Spectrophotometry." Walisongo Journal of Chemistry 5, no. 1 (July 15, 2022): 75–82. http://dx.doi.org/10.21580/wjc.v5i1.10885.

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Determination and characterization of the lycopene content of the n-hexane fraction from potato-leaved tomato (Solanum lycopersicum grandyfolium) using Fourier transform infrared (FTIR) spectrophotometry and UV-Vis spectrophotometry. This study aims to determine the levels and characterization of lycopene compounds from potato-leaved tomato fruit using FTIR and UV-Vis spectrophotometers. The methods in this research include maceration, liquid-liquid extraction, crystallization with antisolvent, chromatography with three eluent systems, identification of lycopene compounds, and characterization of lycopene compounds using FTIR and UV-Vis. The results showed the presence of lycopene compounds based on the spectrum with absorption peaks at wave numbers 2924, 18 cm-1 and 2863, 66 cm-1 indicating C-H (stretching); 1637, 43 cm-1 indicating C=C alkene; and the wave numbers of 1461, 63 cm-1 and 1422, 46 cm-1 indicating the presence of a CH2 (bending) functional group. The results of UV-Vis spectrophotometric characterization showed the presence of lycopene compounds at three main wavelengths, namely at 445, 467, and 500 nm. The level of lycopene compounds produced from the n-hexane extract of potato-leaved tomato fruit was 7.25 mg/gram

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Drozd, J. "Comparison of classic and derivative UV spectrophotometric methods for determination of dextromethorphani hydrobromidum." Acta Facultatis Pharmaceuticae Universitatis Comenianae 59, no. 1 (January 1, 2012): 22–29. http://dx.doi.org/10.2478/v10219-012-0014-8.

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Comparison of classic and derivative UV spectrophotometric methods for determination of dextromethorphani hydrobromidumA method for the fast determination of dextromethorphani hydrobromidum in pharmaceutical preparations by classic spectrophotometry - zero and first-, second- and third-order derivative spectrophotometry, using "peak - peak" (P - P) and "peak - zero" (P - O) measurements has been performed. The calibration curves are linear within the concentration range of 1.0 - 25.0 μg ml-1 for dextromethorphani hydrobromidum. The procedure is simple, rapid and the results are reliable.

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Stiff, T., and S. Jeffers. "Absolute Spectrophotometry of Be Stars." International Astronomical Union Colloquium 92 (August 1987): 211–13. http://dx.doi.org/10.1017/s0252921100116252.

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AbstractAbsolute spectrophotometry data have been obtained for a sample of Be stars. These data were obtained with the York Observatory 60 cm telescope and vidicon spectrophotometer. The data have been corrected for differential atmospheric extinction, instrumental response, and interstellar extinction and calibrated in terms of absolute flux. Absolute Hα and Hβ fluxes have been determined.

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Maslov, Oleksandr Yu, Mykola A. Komisarenko, Yulia S. Kolisnyk, and Tatyana A. Kostina. "Determination of catechins in green tea leaves by HPLC compared to spectrophotometry." Journal of Organic and Pharmaceutical Chemistry 19, no. 3(75) (October 20, 2021): 28–33. http://dx.doi.org/10.24959/ophcj.21.238177.

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Aim. To study the qualitative composition, the quantitative content of catechins in green tea leaves and compare the data obtained with those evaluated by spectrophotometry.Materials and methods. Green tea leaves used for the analysis were collected in Anhui Province, China. The extract for the HPLC analysis was obtained by the maceration method with 60 % ethanol twice in the raw material/extractant ratio of 1 : 20. In the case of the spectrophotometric analysis, green tea leaves were extracted with 70 % ethanol twice by the maceration method in the raw material/extractant ratio of 1 : 20. The analysis of the extract from green tea leaves was performed by high performance liquid chromatography using a Prominence LC-20 Shimadzu chromatographic system (Japan) with a SPD-20AV spectrophotometric detector, an Agilent Technologies Microsorb-MV-150 column (reversed phase, C18 modified silica gel, length – 150 mm, diameter – 4.6 mm, particles size – 5 μm). Substances in the extract were identified by comparing the retention time and the spectral characteristics of the test substances with the same characteristics of the reference standards. Spectrophotometric measurements were carried out using a UV-1000 single beam spectrophotometer (China) with the pair of S90-309Q quartz square cells.Results and discussion. Using high performance liquid chromatography 5 catechins were identified. Among them epigallocatechin-3-O-gallate (10.85 %) predominated, while catechin (0.61 %) had the lowest concentration. The total amount of catechins in green tea leaves was 30.56 and 24.79 % by HPLC and spectrophotometry, respectively. The F- and t-tests showed that there was no significant difference between the results of HPLC and spectrophotometry.Conclusions. The qualitative composition and the quantitative content of catechins have been determined in the extract from green tea leaves by high performance liquid chromatography and spectrophotometry. Both HPLC and spectrophotometric methods can be used to determine the total catechin content in green tea leaves. The high content of catechins makes the extract promising for further study and creation of new herbal medicinal products and dietary supplements. The results obtained will be used for standardization of green tea leaves and for future pharmacological research of its extract.

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Kozioł, Michał, Daria Wotzka, Tomasz Boczar, and Paweł Frącz. "Application of Optical Spectrophotometry for Analysis of Radiation Spectrum Emitted by Electric Arc in the Air." Journal of Spectroscopy 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/1814754.

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This paper presents the results of measurement and analysis of optical radiation emitted by a free burning electric arc. The aim was to determine the application possibilities of optical spectrophotometry for detection of electric arcs. The research works considered electric arc generated with a constant voltage supply between two copper electrodes in the air, carried out under laboratory conditions. A high resolution optical spectrophotometer was used for registration of optical radiation. The analyses involved determination of two dimensionless descriptors obtained for the gathered spectra. Moreover, for each of the registered intensity distributions, the energy values were calculated for three frequency ranges. Based on the measured signals, the possibility of application of spectrophotometry for the optical radiation analysis was confirmed. The analysis indicated that the most energy of optical radiation is detected for the range of 200–780 nm, while above 780 nm almost no optical energy is emitted. Spectrophotometric studies performed in the UV-NIR range are of interest since one can obtain information about the structural defects (at lower wavebands) or impurities and/or point defects (at low energies bands). It was also stated that the obtained descriptors may be applied for diagnosis and identification of electric arc purposes.

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Skripnikova, Tatyana A., Svetlana S. Lysova, Yuri E. Zevatskii, and Tatyana V. Artamonova. "ANALYTICAL WAVELENGTHS IN THE SPECTROPHOTOMETRIC INVESTIGATION OF EQUILIBRIA IN SOLUTIONS." Bulletin of the Saint Petersburg State Institute of Technology (Technical University) 68 (2024): 3–9. http://dx.doi.org/10.36807/1998-9849-2024-68-94-3-9.

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The review discusses approaches to determining the analytical wavelength in the spectrophotometric determination of thermodynamic equilibrium constants in solutions. Particular attention is paid to the use of the traditional spectrophotometric method and the method of concentration UV/Vis spectrophotometry, which has not yet been widely used

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Dagdu, Kedar Vikas, Manoj Gadhave, Shubham Bhujbal, and Bhushan Shrinath. "Area Under Curve by UV Spectrophotometric Method for Determination Albendazole in Bulk." Journal of Drug Delivery and Therapeutics 9, no. 6 (November 15, 2019): 47–50. http://dx.doi.org/10.22270/jddt.v9i6.3667.

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The aim of present investigation is to establish simple, precise, and rapid Spectrophotometric method for the quantification of Albendazole in Active Pharmaceutical Ingredient. In this, work is carried out to for estimation of Albendazole bulk by utilizing an Area under Curve (AUC) method using UV – Visible Spectrophotometry. The study is designed to validate the developed methods as per ICH guidelines. For this purpose the wavelength range between 200-400 nm was selected. Methanolic distilled water (50 ml methanol used for stock solution and serial dilution in 25 ml distilled water) was used as a solvent throughout the work. Linearity was obtained in concentration range 2 to 10 ɥg/ml (r2 = 0.992) for the method. The developed method was found to be simple, linear, accurate, precise and highly sensitive and which can be used for routine quality control analysis for Spectrophotometric estimation of Active Pharmaceutical Ingredient. KeywordS: Albendazole, linearity, AUC, spectrophotometer, methanol, distilled water.

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Kompantseva, E. V., A. Yu Ayrapetova, and A. S. Saushkina. "Spectrophotometric Determination of Hydroxycinnamic Acids in Herbal Drugs. Part 1. Direct Spectrophotometry (Review)." Bulletin of the Scientific Centre for Expert Evaluation of Medicinal Products. Regulatory Research and Medicine Evaluation 14, no. 2 (April 5, 2024): 181–95. http://dx.doi.org/10.30895/1991-2919-2024-14-2-181-195.

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INTRODUCTION. Current scientific research aims to discover new plant sources of hydroxycinnamic acids for the development of novel medicinal products. Most commonly, the quantitative determination of hydroxycinnamic acids in herbal drugs involves testing procedures based on spectrophotometry and its modifications.AIM. This study aimed to establish the possibility of the quantification of hydroxycinnamic acids in herbal drugs by direct spectrophotometry.DISCUSSION. This review presents organised information on the use of direct spectrophotometry to quantify hydroxycinnamic acids in 70 plant species growing or cultivated in the Russian Federation. The review covers publications in Russian for the period from 2007 to 2023. According to the reviewed publications, direct spectrophotometry is an easy-to-use and highly reproducible method that does not require additional reagents or labour-intensive steps. Direct spectrophotometry may result in an overestimation of the hydroxycinnamic acid content due to overlapping absorption bands of polyphenolic compounds with different structures.CONCLUSIONS. Direct spectrophotometry can be considered as a method for measuring the total content of phenolic compounds (as well as hydroxycinnamic acids) in herbal drugs. Different approaches to direct spectrophotometric quantification of hydroxycinnamic acids in herbal drugs by can serve as a methodological basis for developing analytical procedures specific to the chemical compositions of biologically active compounds in herbal drugs and their extracts.

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Kurdaikar, S. S., A. Fernandes, S. V. Gandhi, P. Pattewar, and A. A. Mahajan. "Spectrophotometric Determination of Carbimazole and Its Major Impurity, Degradation Product and Metabolite: Methimazole -=SUP=-*-=/SUP=-." Оптика и спектроскопия 129, no. 7 (2021): 972. http://dx.doi.org/10.21883/os.2021.07.51090.1046-21.

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The present research work was carried out in order to develop simple, accurate and precise UV sprctrophotometric methods having comparable sensitivity as that of sophisticated chromatographic techniques. Two methods were developed namely first derivative spectrophotometry and ratio spectra derivative spectrophotometry for accurate determination of specified impurity methimazole (imp A) in presence of drug carbimazole. First derivative spectrophotometric method involves recording of zero order spectra of both the drugs carbimazole and methimazole and its mixture in the range of 200-400 nm and subsequent conversion of these spectra into first derivative spectra. The drugs carbimazole and methimazole were determined by using zero crossing wavelengths of 227 and 260 nm respectively. In the second approach, ratio spectra were recorded for carbimazole and methimazole by selecting appropriate divisor concentration and converted into first derivative spectra. The determination of carbimazole and methimazole were carried out at wavelength 226.2 and 257 nm, respectively. Both the methods were validated as per ICH guideline. The drugs carbimazole and methimazole showed linear response with good correlation coefficient and exhibited specificity, accuracy and precision within acceptable range. The second method of ratio spectra derivative spectrophotometry was found more sensitive as compare to first derivative spectrophotometry in detecting level of impurity methimazole up to 0.5% as per official specification. Hence, these developed methods can be used as alternative to sophisticated chromatographic technique for determination of assay and related impurity in bulk drug and formulation. Keywords: carbimazole, methimazole, first derivative spectrophotometry, ratio spectra derivative spectrophotometry.

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SAAD ANTAKLI, Raghad Kabbani, and And Rama Labban. "Analytical Spectrometric Study For Determining Dapagliflozin Propanediol Monohydrate Individually Or In Presence Of Metformin Hydrochloride In Tablets Formulation." JOURNAL OF ADVANCES IN CHEMISTRY 17 (September 10, 2020): 80–87. http://dx.doi.org/10.24297/jac.v17i.8812.

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First simple spectrophotometric method was developed and applied to determine Dapagliflozin Propanediol Monohydrate by Zero Spectrophotometry and First Derivative Spectrophotometric method for determining of Dapagliflozin Propanediol Monohydrate (DAPA) in the presence of Metformin Hydrochloride (MET). Zero spectrophotometric (ZS) was applied for the determination of (DAPA) at 223.5 nm. Linearity range was (2.61– 31.23) µg/mL. Regression analysis showed a good correlation coefficients R2 = 0.9989. The limit of detection (LOD) and limit of quantification (LOQ) were to be 0.569 µg/mL and 1.724 µg/mL, respectively. Derivative spectrophotometric (1DS) was applied for the determination of (DAPA) in the presence (MET). (DAPA) was determined at 233 nm (1D233). Linearity ranges were (5.21 – 41.64) µg/mL for (DAPA). Regression analysis showed a good correlation coefficients R2 = 0.9994. The limit of detection (LOD) and limit of quantification (LOQ) were to be 0.732 µg/mL and 2.218 µg/mL for (DAPA). The proposed Zero spectrophotometry method was applied to analysis individual (DAPA), and the derivative (1D233) method was applied to analysis (DAPA) individually or with (MET) combination in Syrian trademark drugs.

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Sarode, Dhananjay B., Sopan T. Ingle, and Sanjay B. Attarde. "FORMULA ESTABLISHMENT OF COLORLESS Pb(II) COMPLEX WITH N-BENZOYL-N-PHENYL HYDROXYLAMINE (BPA) USING ATOMIC ABSORPTION SPECTROSCOPY." Indonesian Journal of Chemistry 12, no. 1 (February 14, 2012): 12–19. http://dx.doi.org/10.22146/ijc.21366.

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A new method for determination of stoichiometry of colorless complexes by using atomic absorption spectrophotometric technique in continuous variation method and slope ratio method was described here. This method can be used in same manner as that of mole ratio method and slope ratio method. In this method atomic absorption spectroscopy was used instead of UV-Vis spectrophotometry. Atomic absorption spectrophotometric technique is superior to UV-Vis spectrophotometry as it can be applied to colorless soluble complexes. Pb(II) and n-benzoyl-n-phenyl hydroxylamine react to form colorless complex at pH 6.5, which can be easily determined by this method. It was found that Pb(II) forms 1:2 complex with n-benzoyl-n-phenyl hydroxylamine and is quantitatively extracted back to aqueous solution for AAS analysis.

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Ganorkar, S. B., D. M. Dhumal, and A. A. Shirkhedkar. "APPLICATION OF UV-SPECTROPHOTOMETRY FOR DETERMINATION OF ZILEUTON IN BULK AND IN TABLETS." INDIAN DRUGS 50, no. 06 (June 28, 2013): 40–44. http://dx.doi.org/10.53879/id.50.06.p0040.

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Zileuton is an orally active inhibitor of 5-lipoxygenase and found to inhibit leukotrienes (LTB4 , LTC4, LTD4 , and LTE4) formation and well-known for the effective treatment of asthma. Rapid, economical and simple ‘Zero order UV-spectrophotometry’ and ‘First order derivative UV-spectrophotometry’ have been developed for estimation zileuton in bulk and in-house tablets. Zileuton showed maximum absorbance at 258.4 nm in 0.01M NaOH. For Zero order UV-spectrophotometric method (Method I), two wavelengths 243.4 nm and 271.0 nm were selected for the determination of area under curve (AUC). In First order derivative UV-spectrophotometry (Method II), two wavelengths 260.0 nm and 279.60 nm were selected for determination of AUC. For both these methods, zileuton followed linearity in the concentration range of 4 - 24 µg/ mL with correlation coefficient value of 0.999. Both methods were validated as per ICH guidelines.

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Forbes, Patricia B. C., and Johan A. Nöthling. "Shedding light on spectrophotometry: The SpecUP educational spectrophotometer." South African Journal of Science 110, no. 1/2 (2014): 1–5. http://dx.doi.org/10.1590/sajs.2014/20130096.

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WANG, C., and P. A. SCHUPPLI. "DETERMINING AMMONIUM OXALATE-EXTRACTABLE Si IN SOILS." Canadian Journal of Soil Science 66, no. 4 (November 1, 1986): 751–55. http://dx.doi.org/10.4141/cjss86-076.

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Determination of oxalate-extractable Si and Al is useful in assessing the degree of accumulation of allophane-like materials in Podzolic soils. Three procedures were tested for determining Si: manual spectrophotometry, automated spectrophotometry and atomic absorption. For concentrations of oxalate-extractable Si above 0.5 g kg−1, there was no significant difference among results by the three procedures. For lower concentrations of Si, results by atomic absorption were higher than those by the spectrophotometric procedures. Determination by Si by autoanalyzer is the preferred procedure as it is convenient, sensitive and reliable. Key words: Oxalate Si, Podzolic soil, autoanalyzer

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Hadi, Samsul, Amalia Khairunnisa, and Kunti Nastiti. "Descriminant analysis of flowers, leaves, stems of combretum indicum varr.M and Varr.B with UV-vis spectrophotometric chemometric method." E3S Web of Conferences 373 (2023): 03024. http://dx.doi.org/10.1051/e3sconf/202337303024.

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Combertum indicum has two varieties, namely varr.M and Varr.B., so to maintain the truth of the sample it is necessary to discriminate. The way to distinguish these two varieties can use the UV-vis spectrophotometric approach. The method used in chemometrics uses five sampling districts, namely Banjarmasin, Banjarbaru, Banjar, Tanah Laut, Tanah Spice, the equipment used is spectrophotometry UV-vis. Data analysis uses descriptive analysis. The results of the identification of flower performance index obtained are 88.9; Leave identification 92.2; stem identification 86.8. In conclusion, the combination chemometric UV-vis spectrophotometry succeeded in differentiating combertum indicum varr.M and Varr.B.

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Webb, D. J., B. K. Burnison, A. M. Trimbee, and E. E. Prepas. "Comparison of Chlorophyll a Extractions with Ethanol and Dimethyl Sulfoxide/Acetone, and a Concern about Spectrophotometric Phaeopigment Correction." Canadian Journal of Fisheries and Aquatic Sciences 49, no. 11 (November 1, 1992): 2331–36. http://dx.doi.org/10.1139/f92-256.

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Chlorophyll a (Chl a) in water samples from three mesotrophic to eutrophic lakes in north-central Alberta was extracted with one of three solvents (95% ethanol, 90% ethanol, or a 2:3 mixture of dimethyl sulfoxide and 90% acetone (DMSO/acetone)) and analyzed by two techniques (spectrophotometry and high pressure liquid chromatography (HPLC). The dominant phytoplankton were blue-green algae and diatoms. Total Chl a concentrations (i.e. no correction for phaeopigments (Pha)) were not significantly different among solvents (P > 0.5). Total Chl a concentrations from spectrophotometric analyses were significantly higher than those from HPLC analyses (4.2 ± 0.88 and 2.6 ± 0.50 μg∙L−1 respectively, P < 0.05). Pha concentrations derived by spectrophotometry were 64 times higher than those derived by HPLC (1.7 ± 0.52 and 0.025 ± 0.01 μg∙L−1 respectively, P < 0.005). Thus, spectrophotometry appears to dramatically overestimate Pha concentrations and may overestimate total Chl a (i.e. no correction for Pha). Therefore, ethanol and DMSO/acetone are equally suitable for Chl a extraction from natural populations dominated by blue-green algae and/or diatoms, but if information on Pha and/or accessory pigments is required, HPLC analyses are the appropriate route rather than spectrophotometry.

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Belsheva, Mariia N., Anastasia V. Guseva, Fedor A. Koleda, Polina V. Murlina, and Larisa P. Safonova. "Position-force control in the identification of tissue structures using the spectrophotometric method." Digital Diagnostics 5, no. 1S (July 3, 2024): 12–14. http://dx.doi.org/10.17816/dd626641.

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BACKGROUND: Time-resolved spectrophotometry enables the contact probing of biological tissues at a depth of two millimeters to several centimeters, with a spatial resolution of one to five millimeters. This technique provides a quantitative assessment of optical parameters, concentrations of main chromophores, identification of tissue type and inclusions in the volume, which is relevant for intraoperative diagnostics [1–3]. The variability of optical properties during probe squeezing necessitates the implementation of force control of squeezing, which, like positioning, is used in robotic surgery and diagnostics [4–11]. A combined mechanical and spectrophotometric approach holds promise in this regard. However, further research is required concerning spectrophotometer setup, the development of test objects, and the determination of the possibilities of positioning-force-controlled spectrophotometry for the identification of tissues and inclusions. Development of approaches to active positional force control to study the functionality of spectrophotometry in identifying tissue structures. MATERIALS AND METHODS: An experimental bench was constructed based on a two-wavelength spectrophotometer with OxiplexTS frequency approach (ISS Inc., USA). This bench allows for the position control of the optical probe using a robotic mini-manipulator (U-Arm, China). Additionally, a software program was developed to record the pressing force of the fabricated probe in a customized nozzle for the manipulator. Finally, an algorithm was proposed for processing experimental data to estimate biomechanical, optical, and physiological parameters of the tissue. A single healthy subject participated in the experimental study. Measurements were conducted on the dorsal and ventral surfaces of the forearm and on the palmar surface of the hypotenar. RESULTS: The quantitative assessment of elastic properties of biological tissue can be achieved through the use of force-displacement data. The simultaneous registration of optical parameters, concentrations of hemoglobin fractions in a unit of the investigated volume, and tissue saturation in the dynamics of probe pressing allows for the estimation of microcirculatory blood flow, the revelation of the presence and type of large vessels. The standard silicone test objects used for spectrophotometer calibration do not align with the mechanical properties of biological tissues. Given the diminutive dimensions of the optical probe, this discrepancy introduces an additional degree of uncertainty in the quantitative assessment of tissue properties. CONCLUSIONS: The addition of active force control and automated positioning of the optical probe during spectrophotometry enhances its functional capabilities for identifying tissue structures and expands its applications in robotic pre-, intra- and post-operative diagnostics. For further studies on a larger number of tissues, tissue structures and mimicking tissue test objects, an improvement of the experimental bench is required: increase of the sensitivity of the force sensor, smoothness and discreteness of the motion during positioning, e.g. by replacing the mini manipulator by a collaborative robot. The improvement of the software part implies the implementation of synchronization with OxiplexTS through its input interface module, writing a program for automatic surface scanning.

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Wagner, Jakub, Roman Z. Morawski, and Andrzej Miękina. "Comparison of Five Svd-Based Algorithms for Calibration of Spectrophotometric Analyzers." Metrology and Measurement Systems 21, no. 2 (June 1, 2014): 191–204. http://dx.doi.org/10.2478/mms-2014-0017.

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Abstract Spectrophotometry is an analytical technique of increasing importance for the food industry, applied i.a. in the quantitative assessment of the composition of mixtures. Since the absorbance data acquired by means of a spectrophotometer are highly correlated, the problem of calibration of a spectrophotometric analyzer is, as a rule, numerically ill-conditioned, and advanced data-processing methods must be frequently applied to attain an acceptable level of measurement uncertainty. This paper contains a description of four algorithms for calibration of spectrophotometric analyzers, based on the singular value decomposition (SVD) of matrices, as well as the results of their comparison - in terms of measurement uncertainty and computational complexity - with a reference algorithm based on the estimator of ordinary least squares. The comparison is carried out using an extensive collection of semi-synthetic data representative of trinary mixtures of edible oils. The results of that comparison show the superiority of an algorithm of calibration based on the truncated SVD combined with a signal-to-noise ratio used as a criterion for the selection of regularisation parameters - with respect to other SVD-based algorithms of calibration.

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Popova, Marina I., Tatyana A. Kobeleva, and Alik I. Sichko. "Spectrophotometric analysis of carvedilol in a medication based on aquacomplex of titanium glycerosolvate." Aspirantskiy Vestnik Povolzhiya 22, no. 2 (November 1, 2022): 67–72. http://dx.doi.org/10.55531/2072-2354.2022.22.2.67-72.

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Aim to develop a methodology for quantitative spectrophotometric analysis of carvedilol in the "Carvedilosol" medication based on aquacomplex of titanium glycerosolvate. Material and methods. During the analysis we used the pharmaceutical substance "Carvedilol", gel "Tizol", ointment "Carvedilosol" consisting of 0.5% beta-blocker in titanium glycerohydrogel. The spectrophotometry was applied, registration of optical density and electron spectra was performed on spectrophotometer SF-2000. The following parameters were chosen for validation of the methodology: specificity, linearity, precision, correctness. Results. It is reasonable to analyze Carvedilol at a wavelength of 243 nm with the limit of quantitative determination of 0.761 g/ml. The results of the study showed that the weight of carvedilol in the ointment is within acceptable limits (0.0404-0.0548 g) according to the regulatory documentation for soft dosage forms (Order of the Ministry of Health of the Russian Federation No. 751n dated 26.10.2015). Conclusion. Optimal conditions for the implementation of spectrophotometric method of analysis were selected for detection of the content of carvedilol in the ointment "Carvedilosol" with a relative error not exceeding 1.80 %.

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Antakli, Saad, Leon Nejem, and Monzer Alraii. "Determination of Glibenclamide By Analytical Spectrophotometry." JOURNAL OF ADVANCES IN CHEMISTRY 18 (April 24, 2021): 40–48. http://dx.doi.org/10.24297/jac.v18i.8963.

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Simple and rapid spectrophotometric method was developed and applied to determine Glibenclamide (GB) by zero spectrophotometric method and first derivative spectrophotometric method for determining of (GB) in the presence of Metformin hydrochloride (MET). Zero spectrophotometric (ZS) method was applied for the determination of (GB) at λmax = 300 nm. Linearity range was (4 – 360) μg/mL. Regression analysis showed a good correlation coefficients R2 = 0.99993. The limit of detection (LOD) and limit of quantification (LOQ) were to be 0.65 μg/mL and 2.31 μg/mL, respectively. First derivative spectrophotometric (1DS) method was applied for the determination of (GB) in the presence (MET). (GB) was determined at 317 nm (1D317). Linearity ranges were (4 – 240) μg/mL for (GB). Regression analysis showed a good correlation coefficients R2 = 0.999914. The limit of detection (LOD) and limit of quantification (LOQ) were to be 0.60 μg/mL and 1.83 μg/mL for (GB). The proposed zero spectrophotometry method was applied to analysis individual (GB), and the derivative (1D317) method was applied to analysis (GB) individually or combined with (MET) in Syrian trademark drugs. The proposed method is simple, direct, sensitive and do not require any extraction process. Thus, this method could be readily applicable for the quality control and routine analysis.

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Roohparvar, Rasool, Mohammad Ali Taher, and Alireza Mohadesi. "Simultaneous Determination of Nickel and Copper by H-Point Standard Addition MethodFirst-Order Derivative Spectrophotometry in Plant Samples After Separation and Preconcentration on Modified Natural Clinoptilolite as a New Sorbent." Journal of AOAC INTERNATIONAL 91, no. 3 (May 1, 2008): 637–45. http://dx.doi.org/10.1093/jaoac/91.3.637.

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Abstract For the simultaneous determination of nickel(II) and copper(II) in plant samples, a rapid and accurate method was developed. In this method, solid-phase extraction (SPE) and first-order derivative spectrophotometry (FDS) are combined, and the result is coupled with the H-point standard addition method (HPSAM). Compared with normal spectrophotometry, derivative spectrophotometry offers the advantages of increased selectivity and sensitivity. As there is no need for carrying out any pretreatment of the sample, the spectrophotometry method is easy, but because of a high detection limit, it is not so practical. In order to decrease the detection limit, it is suggested to combine spectrophotometry with a preconcentration method such as SPE. In the present work, after separation and preconcentration of Ni(II) and Cu(II) on modified clinoptilolite zeolite that is loaded with 2-[1-(2-hydroxy-5-sulforphenyl)-3-phenyl-5-formazano]-benzoic acid monosodium salt (zincon) as a selective chromogenic reagent, FDS-HPSAM, which is a simple and selective spectrophotometric method, has been applied for simultaneous determination of these ions.With optimum conditions, the detection limit in original solutions is 0.7 and 0.5 ng/mL, respectively, for nickel and copper. The linear concentration ranges in the proposed method for nickel and copper ions in original solutions are 1.1 to 3.0 103 and 0.9 to 2.0 103 ng/mL, respectively. The recommended procedure is applied to successful determination of Cu(II) and Ni(II) in standard and real samples.

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Kholifa, Mulik, Tri Mulyono, and Yeni Maulidah Muflihah. "Simultaneous Determination of Magnesium (Mg2+) and Ammonium (NH4+) by Flow Injection Analysis." Jurnal ILMU DASAR 19, no. 1 (February 28, 2018): 1. http://dx.doi.org/10.19184/jid.v19i1.5483.

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An automatic method for the simultaneous determination of magnesium and ammoniun by flow injection analysis is described. This analysis used two detectors, potentiometry and spectrophotometry, for the determination of magnesium and ammonium simultaneously. Potentiometric detectors are used to detect ammonium ions, whereas spectrophotometer detectors are used to detect the presence of magnesium ions. The performance of the FIA system includes linear range linearity, limit of detection, sensitivity, reproducibility and recovery test. Spectrophotometry FIA showed good performance with several criteria of linearity with regression value of 0.9918, the detection limit of 0.06 ppm, a sensitivity of 0.0115, repeatability of less than 2% and the percent recovery of 91,6%. While potentiometric FIA showed th performance with several criteria of linearity with regression value of 0.9896, the detection limit of 0.17 ppm, a sensitivity of 40.747 mV per decade of concentration, repeatability of less than 2% and the percent recovery of 89,7%. Keywords: Flow Injection Analysis, spectrophotometry, potensiometry, simultaneous

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Pratama, Mohammad Rizki Fadhil, Suratno Suratno, and Evi Mulyani. "Profile of Thin-Layer Chromatography and UV-Vis Spectrophotometry of Akar Kuning Stem Extract (Arcangelisia flava)." Borneo Journal of Pharmacy 1, no. 2 (October 6, 2018): 72–76. http://dx.doi.org/10.33084/bjop.v1i2.367.

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This study aims to obtain the profile of Thin-Layer Chromatography (TLC) and Ultraviolet-Visible (UV-Vis) spectrophotometry from ethanol extract of akar kuning stems (Arcangelisia flava) from Central Kalimantan. The TLC method is used with the orientation phase of the combination of polar-non-polar solvents resulting from orientation, while ethanol is used as the solvent for UV-Vis spectrophotometers. TLC results showed the formation of 3 stains on a combination of polar solvents chloroform : methanol : water while in a non-polar solvent combination n-hexane : ethyl acetate did not show any stains. Comparison of retention factor (Rf) values show the best combination of polar solvents to separate stains at a ratio of 5 : 2 : 1, respectively. Separation in 2-dimensional TLC with polar solvents showed a similar pattern with 1-dimensional separation in the form of 3 stains. UV-Vis spectrophotometer results showed 4 main peaks with wavelength 227.2; 267.4; 345.2; and 425.3 nm, respectively. The profile of the peak formed is very similar to that shown by berberine, one of the main metabolites of akar kuning. TLC and UV-Vis spectrophotometers profiles obtained are expected to support further research using akar kuning stems, especially those from Central Kalimantan.

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Morris, Rob. "Spectrophotometry." Current Protocols Essential Laboratory Techniques 00, no. 1 (January 2008): 2.1.1–2.1.24. http://dx.doi.org/10.1002/9780470089941.et0201s00.

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Butts, Bill. "Spectrophotometry." Chemical Educator 3, no. 2 (April 1998): 1–7. http://dx.doi.org/10.1007/s00897980198a.

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Khan, Zamir G., Amod S. Patil, and Atul A. Shirkhedkar. "Estimation of Tadalafil Using Derivative Spectrophotometry in Bulk Material and in Pharmaceutical Formulation." International Journal of Spectroscopy 2014 (May 21, 2014): 1–6. http://dx.doi.org/10.1155/2014/392421.

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Four simple, rapid, accurate, precise, reliable, and economical UV-spectrophotometric methods have been proposed for the determination of tadalafil in bulk and in pharmaceutical formulation. “Method A” is first order derivative UV spectrophotometry using amplitude, “method B” is first order derivative UV spectrophotometry using area under curve technique, “method C” is second order derivative UV spectrophotometry using amplitude, and “method D” is second order derivative UV spectrophotometry using area under curve technique. The developed methods have shown best results in terms of linearity, accuracy, precision, and LOD and LOQ for bulk drug and marketed formulation as well. In N,N-dimethylformamide, tadalafil showed maximum absorbance at 284 nm. For “method A” amplitude was recorded at 297 nm while for “method B” area under curve was integrated in the wavelength range of 290.60–304.40 nm. For “method C” amplitude was measured at 284 nm while for “method D” area under curve was selected in the wavelength range of 280.80–286.20 nm. For methods A and B, tadalafil obeyed Lambert-Beer’s law in the range of 05–50 μg/mL while for “methods C and D”, tadalafil obeyed Lambert-Beer’s law in the range of 20–70 μg/mL, and-for “methods A, B, C, and D” the correlation coefficients were found to be > than 0.999.

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Prats, M. "Tools in spectrophotometry and differential spectrophotometry." Biochemical Education 17, no. 3 (July 1989): 151–53. http://dx.doi.org/10.1016/0307-4412(89)90102-7.

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Turak, Fatma, and Mahmure Ustun Ozgur. "Simultaneous Determination of Allura Red and Ponceau 4R in Drinks with the Use of Four Derivative Spectrophotometric Methods and Comparison with High-Performance Liquid Chromatography." Journal of AOAC INTERNATIONAL 96, no. 6 (November 1, 2013): 1377–86. http://dx.doi.org/10.5740/jaoacint.12-393.

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Abstract Four simple, rapid, sensitive, and accurate spectrophotometric methods were developed for the simultaneous determination of Allura Red (AR) and Ponceau 4R (P) without previous chemical separation. The first method, derivative spectrophotometry, depends on first derivative spectrophotometry with zero-crossing and peak-to-base measurement. The second method, derivative ratio spectrophotometry, uses the first derivative of the ratio spectra. The ratio spectra are obtained by dividing the absorption spectra of a binary mixture by that of one of the components. The third method, differential derivative spectrophotometry, is based on the measurement of the difference absorptivities derivatized in the first order of a sample extract in 0.1 M NaOH relative to that of an equimolar solution in 0.1 M HCI. The fourth method, based on the compensation technique, is presented for the derivative spectrophotometric determination of binary mixtures with overlapping spectra by using ratios of the derivative maximum or minimum; the exact compensation of either component in the mixture can be achieved, followed by its determination. All the proposed methods were successfully applied to the determination of the colorants in their laboratory mixtures and granulated drinks without any interference by the ingredients. AR and P showed good linearity, with regression coefficients of 0.9994–0.9999. The LOD and LOQ values ranged from 0.059 to 0.102 and 0.198 to 0.341 μg/mL, respectively. The intraday and interday precision tests produced good RSD values (<1.37%); recoveries ranged from 98.75 to 100.37% for all four methods. The common ingredients and additives did not interfere in the AR and P determination. The results of the proposed methods were statistically compared with the results of an HPLC method given in the literature (Nordic Committee on Food Analysis; NMKL 130) at the 95% confidence level by Student's t-test and the variance ratio F-test. No statistically significant difference was found among these methods.

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Uncu, Livia, Vladilena Evtodienco, Ecaterina Mazur, Elena Donici, and Vladimir Valica. "Validation of the spectrophotometric method for the dosing of some combined capsule." Moldovan Medical Journal 64, no. 4 (October 2021): 10–16. http://dx.doi.org/10.52418/moldovan-med-j.64-4.21.02.

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Background: UV-Vis spectrophotometry remains the most accessible spectral method with a high degree of sensitivity and information. The advantage of the method consists in its universality, the ability to combine with other methods, the minimum error, as well as its economic efficiency. The objective of this study was the determination of some validation parameters for the spectrophotometric method of dosing piracetam and nicergoline in combined capsules. Material and methods: Agilent 8453 UV-Vis spectrophotometer, reference standards of piracetam and nicergoline, 0.1 M HCl methanolic solution. Validation of the spectrophotometric method according to the requirements of the ICH guide “Q2R1: For analytical procedures and validation”. Results: Linearity was investigated on concentration ranges 5-40 µg / mL. The regression (R2 ) values were 0.9998 for nicergoline and 0.998 for piracetam, respectively. The limit of detection was 1.737 µg / mL for nicergoline and 0.369 µg / mL for piracetam. Quantification limit values were also calculated as 5.265 and 1.118 µg / mL for nicergoline and piracetam, accordingly. The results obtained showed that the developed spectrophotometric method is accurate, precise and robust, because the value of the relative standard deviation was less than 1.0%. Conclusions: The developed spectrophotometric method showed specificity, linearity, accuracy, precision and robustness, and can be applied on the concentration range between 80-120% of the nominal value of the content of nicergoline and piracetam in the preparation.

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Logoyda, L. S., O. B. Polyauk, D. B. Korobko, and M. B. Chir. "Development and Validation of Methods of Quantitative Determination of Loratadine in Tablets." Asian Journal of Pharmaceutical Research and Health Care 8, no. 2 (April 20, 2016): 62. http://dx.doi.org/10.18311/ajprhc/2016/2372.

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<p>Methods for the quantitative determination of loratadine tablets by differential spectrophotometry and photo-colorimetry have been developed. During the procedure parameters (range of application methods, stability, specificity, robasnist, convergence, internal laboratory accuracy (precision), accuracy, reproducibility) have been considered. The results indicate that the method photo-colorimetry has not met modern criteria for analytical methods for quantitative determination of parameters such as stability, accuracy and linearity, so other validation parameters (robasnist, convergence and inter-laboratory precision) have been determined only by spectrophotometric methods. It is found that the technique of quantitative determination of loratadine by differential spectrophotometry is accurate, correct, reproducible and linear, to determine its suitability for use in pharmaceutical analysis.</p>

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Atole, Dipali M., and Hrishikesh H. Rajput. "ULTRAVIOLET SPECTROSCOPY AND ITS PHARMACEUTICAL APPLICATIONS- A BRIEF REVIEW." Asian Journal of Pharmaceutical and Clinical Research 11, no. 2 (February 1, 2018): 59. http://dx.doi.org/10.22159/ajpcr.2018.v11i2.21361.

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Rapid and easy analytical methods are needed due to increasing number of multicomponent formulations, biotherapeutic products and samples of complex matrix in que. Number of Ultraviolet (UV) spectrophotometric methods used for these purpose. Different types of UV spectrometric methods developed on the basis of principle of additivity, absorbance difference, processing absorption spectra. The aim of this review is to present information on simultaneous equation method, difference spectrophotometry, derivative spectrophotometry, absorbance ratio spectra, derivative ratio spectra, successive ratio - derivative spectra, Q-absorbance ratio method, absorptivity factor method, dual wavelength method, absorption factor method, multivariate chemometric methods, and isosbestic point method. A brief summary on theories, mathematical background and some applications of these methods are presented here.

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Adam Mustapa, Mohamad, Muhammad Taupik, and Jumriani Rannu. "Karakterisasi Senyawa Minyak Atsiri Ekstrak Etil Asetat Bawang Putih (allium sativum l.)." Indonesian Journal of Pharmaceutical Education 1, no. 2 (May 15, 2021): 127–35. http://dx.doi.org/10.37311/ijpe.v1i2.11767.

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Garlic (Allium sativum L.) is one of tuber vegetable crops that is widely grown in various countries in the word and is often used as food spices and medicines. The purpose of this study was to characterize the volatile oil compound ethyl acetate extract of garlic (Allium sativum L.) using Uv-Vis and IR spectrophotometric metods. Several methods used in this research included extraction, identification of compounds, fractionation, thin layer chromatography, prepative thin layer chromatography, and characterization of compounds using Uv-Vis spectrophotometry and IR spectrophotometry. A total of 3000 grams od garlic was macerated using 70% ethanol, then evaporated and obtained a thick extract of 421.5 grams. The results of thin layer chromatography used an eluent ratio of Methanol : Ethyl Acetate (4:2) obtained stains with an Rf value of 0,55. The optimizion result of maximum wavelength of garlic isolated (Allium sativum L.) is 232 nm wich indicated the presence of an electron transition n→σ*.The results of IR spectrophotometry had fuctional groups at wave numbers 3231.530 cm-1 (N-H), 1637.48 cm-1 (C=O), 1014.65 cm-1(C-N).

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Oppe, Tércio Paschke, Júlia Menegola, and Elfrides Eva Scherman Schapoval. "DEVELOPMENT AND VALIDATION OF UV SPECTROPHOTOMETRY AND LIQUID CHROMATOGRAPHY METHODS FOR DETERMINATION OF CEFPIROME IN RAW MATERIAL AND PHARMACEUTICAL DOSAGE." Drug Analytical Research 3, no. 1 (July 17, 2019): 42–50. http://dx.doi.org/10.22456/2527-2616.93809.

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In the present work, analytical methods, UV Spectrophotometry and Liquid Chromatography (HPLC), were developed and validated for quantification of cefpirome, a broad-spectrum fourth-generation cephalosporin, in raw material and powder for injectable preparation. The UV spectrophotometric method was performed at 271 nm, using 0.1 M hydrochloric acid as solvent. The HPLC was carried out using Techsphere ODS column and mobile phase consisted of methanol-water (30:70, v/v) with flow rate 0.8 mL/min and UV detection at 265 nm. The validation method yielded good results demonstrated statistically that the methods were linear, precise, accurate, specific and robust. A preliminary stability study of cefpirome showed that the UV Spectrophotometry and Liquid Chromatography methods were specific for the determination cefpirome in the presence of its degradation products. No statistically difference was observed between the proposed methods. The UV Spectrophotometry and Liquid Chromatography methods allow the quantitation of cefpirome in pharmaceutical dosage form and raw material and can be used for the drug analysis in routine quality control.

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Milne, J. B. "Hexachlorotellurate(IV) hydrolysis equilibria in hydrochloric acid. Measurement by Raman and 125Te NMR spectroscopy and a reconsideration of earlier spectrophotometric results." Canadian Journal of Chemistry 69, no. 6 (June 1, 1991): 987–92. http://dx.doi.org/10.1139/v91-144.

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Solutions of TeO2 (0.001 M) in HCl over a range of concentrations are shown to contain TeCl2(OH)2 in addition to TeCl62−and TeCl4(OH)−. The hydrolysis constants for TeCl62− and TeCl4(OH)− have been determined from a reconsideration of earlier UV-visible spectrophotometric results (1)[Formula: see text]The hydrolysis constants have also been determined by quantitative Raman spectroscopy (K1 = 2.21 (± 0.16) × 104 M3; K2 = 442 ± 57 M3). The agreement between K2 determined by the two methods is good but K1 from spectrophotometry is much larger than that from Raman studies. This disagreement is attributed to ion-pairing which will be significant at the concentration at which the Raman measurements were made (c(TeO2) = 0.50 M). The hydrolysis constant for TeCl62− was also determined from the 125Te NMR spectra of TeO2/HCl solutions, which consisted of one signal, indicating rapid Te exchange between all species. The hydrolysis constant, determined in this way (K1 = 1.92 (± 0.07) × 104 M3) was also low compared to that determined from spectrophotometry. Key words: solution, equilibria, tellurium, hydrochloric acid, Raman spectroscopy, 125Te NMR spectroscopy, UV–visible spectrophotometry.

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E.B. da Silva, Fabiana, Willian R.R. Almeida, Fávero R. Paula, Aline L.H. Müller, Érico M.M. Flores, and Marco F Ferrão. "The effect of pH on the simultaneous determination of Sulfamethoxazole and Trimethoprim by Ultraviolet Spectrophotometry and Multivariate Calibration." Drug Analytical Research 1, no. 2 (December 28, 2017): 15–23. http://dx.doi.org/10.22456/2527-2616.79218.

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Analytical techniques based on Ultraviolet (UV) spectrophotometry are widely used in pharmaceutical analysis, because they are simple and inexpensive. The choice of pH is critical in the development of univariate methods for pharmaceutical quantitation by UV spectrophotometry since changes may modify the absorption spectrum profile. Similar to univariate methods by UV spectrophotometry changes in pH may influence the predictive ability of multivariate models, affecting the resultant analytical performance. We report herein on the influence of pH on the simultaneous determination of sulfamethoxazole (SMZ) and trimethoprim (TMP) in tablets using UV spectrophotometry and multivariate calibration. Data were recorded using a UV spectrophotometer in the wavelength range of 200 to 350 nm. The experimental matrix was constructed using 36 synthetic samples of SMZ-TMP mixtures. The concentration ranges used for the investigation were 14.0 to 26.0 mg L-1 for SMZ and 2.8 to 5.2 mg L-1 for TMP. The Partial Least Squares (PLS) regression models were generated with full-spectrum and multiple pH levels. At pH 4.3, lower values of relative standard error of prediction (RSEP %) for SMZ (1.83) and TMP (1.13) were obtained. The PLS model at pH 4.3 was used for the quantification of real samples (tablets obtained from 13 different manufacturers) and the results were compared with conventional procedures using high performance liquid chromatography (HPLC).

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Vinay, K. B., H. D. Revanasiddappa, Zenita Okram, and Kanakapura Basavaiah. "Permanganometric determination of etamsylate in bulk drug and in tablets." Chemical Industry and Chemical Engineering Quarterly 15, no. 3 (2009): 149–57. http://dx.doi.org/10.2298/ciceq0903149v.

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One titrimetric and two spectrophotometric methods which are simple, selective, sensitive, accurate, precise and economical for the determination of etamsylate (ETM) in bulk drug and in tablets employing permanganate as the oxidimetric reagent are described. In titrimetry, ETM is titrated directly with permanganate in sulphuric acid medium. A direct spectrophotometry (method A) involves treating the aqueous solution of the drug with permanganate in alkaline medium and measuring the bluish green product at 610 nm. In indirect spectrophotometry (method B), the drug solution was treated with a fixed concentration of permanganate in H2SO4 medium, and after a specified time, the unreacted permanganate was measured at 545 nm. The molar combining ratio in titrimetry and the optimum assay conditions were studied. Titrimetry is applicable over 1-10 mg range and the calculations are based on a 1:4 (ETM:KMnO4) molar ratio. In spectrophotometry, Beer's law is obeyed over 0.5- 5.0 and 1.5-15 ?g ml-1 for method A and B, respectively. The molar absorptivity values are calculated to be 2.79?104 and 4.17?104 l mol-1 cm-1 for method A and B, respectively and the corresponding sandell sensitivity values are 0.0094 and 0.0063 ?g cm-2. The limits of detection (LOD) and quantification (LOQ) are also reported for spectrophotometric methods. The applicability of the developed methods was demonstrated by the determination of etamsylate in pure drug as well as in commercial dosage forms.

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Duke, Stephen O., Mary V. Duke, Timothy D. Sherman, and Ujjana B. Nandihalli. "Spectrophotometric and Spectrofluorometric Methods in Weed Science." Weed Science 39, no. 3 (September 1991): 505–13. http://dx.doi.org/10.1017/s004317450007329x.

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The utility, advantages, and disadvantages of several spectrofluorometric and in vivo spectrophotometric methods in plant science are reviewed, with emphasis on their use in weed science. Examples of the use of in vivo, dual-wavelength spectrophotometry to probe the effects of herbicides on cytochromefoxidation/reduction, the P515 chromatic shift, phytochrome synthesis, and other processes are discussed. Use of in vivo spectrophotometry to examine effects of herbicides on phytylation of chlorophyllide, protochlorophyllide photoconversion, porphyrin accumulation, and other processes that result in spectral changes is discussed and examples are provided. Spectrofluorometric methods for pigment identification and quantification and for enzyme assays are illustrated with examples. Spectrofluorometric methods used in conjunction with high-pressure liquid chromatography (HPLC) and thin-layer chromatography (TLC) are discussed.

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Sriariyanun, Malinee, Parita Mutrakulcharoen, Surapun Tepaamorndech, Kraipat Cheenkachorn, and Kittipong Rattanaporn. "A Rapid Spectrophotometric Method for Quantitative Determination of Ethanol in Fermentation Products." Oriental Journal of Chemistry 35, no. 2 (April 5, 2019): 744–50. http://dx.doi.org/10.13005/ojc/350234.

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A rapid and accurate assay for monitoring ethanol production is required to control the progress of fermentation in various industrial-related research and processes. In this study, a spectrophotometric assay to measure ethanol concentration in fermentative sample was developed. Ethanol in unknown aqueous solution was extracted using tri-n-butyl phosphate (TBP) and subsequently oxidized by dichromate reagent. Oxidation product of ethanol with dichromate reagent could be visualized as blue green-color. The A595 value detected by spectrophotometer and ethanol concentration between 0.7%-8.0% was plotted in linear regression with high correlation coefficiency (R2). In addition, concentration of methanol, propanol and butanol were determined as did in ethanol suggesting the broad application of this assay. Our established method was applied to commercial wine and fermentative products from yeast culture broths and the results were compared with Gas Chromatography Mass Spectrophotometry (GCMS) method. In this study, this assay was demonstrated as a cheap, rapid, and high accuracy method for determination of ethanol concentration in unknown solutions.

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Yuliet, Elin Y. Sukandar, and I. K. Adnyana. "Active Subfractions, Phytochemical Constituents, Dipeptidyl Peptidase-IV Inhibitory Activity and Antioxidant of Leaf Extract from Hibiscus surattensis L." Natural Products Journal 10, no. 4 (August 21, 2020): 400–410. http://dx.doi.org/10.2174/2210315509666190626125330.

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Objective: This research aimed to investigate the mechanism of action of leaf extract and active subfraction from English wild sour or Hibiscus surattensis L., evaluating antioxidant activity, and determining phytochemical constituents potential for treating various ailments such as diabetes and hepatitis. Background: Antioxidant potential of ethanolic extracts of leaf and active subfractions (ethyl acetate and water fraction) were evaluated using 2,2-diphenyl-1-picrylhydrazyl, Ferric Reducing Ability of Plasma and Cupric Reducing Antioxidant Capacity assays. Methods: Analysis of total flavonoid and phenolic contents were expressed as Quercetin Equivalent and Gallic Acid Equivalent through spectrophotometric technique. Liquid Chromatography-Mass Spectrophotometry/Mass Spectrophotometry was used to identify phytochemical constituents. Results: The results showed that the ethyl acetate fraction was potentially inhibitory against dipeptidyl peptidase IV (IC50 17.947 ± 4.842μg/mL) and had a high free radical scavenging capacity (IC50 value of 44.10 ± 0.243μg/mL; Ferric Reducing Ability of Plasma and Cupric Reducing Antioxidant Capacity values were found to be 639.70 ± 0.3mg ascorbic acid equivalent/g and 174.89 ± 0.58mg ascorbic acid equivalent/100 g respectively). Ethyl acetate fraction showed high flavonoid and phenolic content with 684.67 ± 0.83mg Quercetin Equivalent/g and 329.23 ± 0.82mg Gallic Acid Equivalent/g. Liquid Chromatography-Mass Spectrophotometry/ Mass Spectrophotometry analysis showed the presence of major compounds, including kaempferol, morin, quercetin, and trifolin. Conclusion: These results may explain the use of these leaves in folk medicine in the control of diabetes through a new mechanism and by preventing diabetic complications by means of their antioxidant properties.

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Kompantseva, E. V., A. S. Saushkina, and A. Yu Ayrapetova. "Spectrophotometric Determination of Hydroxycinnamic Acids in Herbal Drugs. Part 2. Determination of Hydroxycinnamic Acids in the Presence of Polyphenolic Compounds (Review)." Bulletin of the Scientific Centre for Expert Evaluation of Medicinal Products. Regulatory Research and Medicine Evaluation 14, no. 2 (April 5, 2024): 196–206. http://dx.doi.org/10.30895/1991-2919-2024-14-2-196-206.

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INTRODUCTION. Polyphenolic compounds of various classes have pronounced absorption bands overlapping in almost the same ultraviolet region. This superposition of bands complicates the quantification of total hydroxycinnamic acids in herbal drugs by direct spectrophotometry without additional sample preparation.AIM. This study aimed to establish the possibility of quantifying hydroxycinnamic acids in herbal drugs by spectrophotometry in the presence of other polyphenolic compounds.DISCUSSION. This review analyses publications on analytical procedures for the spectrophotometric quantification of hydroxycinnamic acids that are based on the preliminary separation or chemical modification of polyphenolic compounds (combining the use of spectrophotometry, chromatography, extraction, Arnow’s reagent, etc.). The described sample preparation can help to resolve absorption bands in the spectra of polyphenolic compounds. The results of assessing the characteristic parameters of these analytical procedures (selectivity, sensitivity, labour intensity, etc.) can serve as a basis for searching novel approaches to the quantitative determination of hydroxycinnamic acids in plants.CONCLUSIONS. To determine the content of hydroxycinnamic acids in mixtures of polyphenolic compounds, analysts may use special sample preparation (combining spectrophotometry with chromatography and extraction) or chemical modification of the initial compounds. The acquired spectra could benefit from specific mathematical processing (derivative photometry and Vierordt’s method). However, even with the abovementioned approaches, it may not always be possible to increase the selectivity of an analytical procedure. Therefore, there is a need to further improve existing analytical procedures for the quantification of hydroxycinnamic acids and develop new ones.

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Journal articles on the topic 'Spectrophotometry'

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