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International Journal of Analytical Chemistry

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https://www.readbyqxmd.com/read/29209369/detailed-componential-characterization-of-extractable-species-with-organic-solvents-from-wheat-straw
#1
Yong-Chao Lu, Yao Lu, Zhao-Lin Lu, Xian-Yong Wei
Componential analysis of extractives is important for better understanding the structure and utilization of biomass. In this investigation, wheat straw (WS) was extracted with petroleum ether (PE) and carbon disulfide (CS2) sequentially, to afford extractable fractions EFPE and EFCS2, respectively. Detailed componential analyses of EFPE and EFCS2 were carried out with Fourier transform infrared (FTIR) spectroscopy, gas chromatography/mass spectrometry (GC/MS), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy dispersive spectrometry (EDS), and electron probe microanalysis (EPMA)...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/29201056/development-of-a-rapid-and-simple-method-to-remove-polyphenols-from-plant-extracts
#2
Imali Ranatunge, Subshini Adikary, Piumi Dasanayake, Chamira Dilanka Fernando, Preethi Soysa
Polyphenols are secondary metabolites of plants, which are responsible for prevention of many diseases. Polyvinylpolypyrrolidone (PVPP) has a high affinity towards polyphenols. This method involves the use of PVPP column to remove polyphenols under centrifugal force. Standards of gallic acid, epigallocatechin gallate, vanillin, and tea extracts (Camellia sinensis) were used in this study. PVPP powder was packed in a syringe with different quantities. The test samples were layered over the PVPP column and subjected to centrifugation...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/29201055/comparison-of-attenuated-total-reflectance-mid-infrared-near-infrared-and-1h-nuclear-magnetic-resonance-spectroscopies-for-the-determination-of-coffee-s-geographical-origin
#3
Jessica Medina, Diana Caro Rodríguez, Victoria A Arana, Andrés Bernal, Pierre Esseiva, Julien Wist
The sensorial properties of Colombian coffee are renowned worldwide, which is reflected in its market value. This raises the threat of fraud by adulteration using coffee grains from other countries, thus creating a demand for robust and cost-effective methods for the determination of geographical origin of coffee samples. Spectroscopic techniques such as Nuclear Magnetic Resonance (NMR), near infrared (NIR), and mid-infrared (mIR) have arisen as strong candidates for the task. Although a body of work exists that reports on their individual performances, a faithful comparison has not been established yet...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/29181027/dispersive-solid-phase-extraction-for-the-analysis-of-veterinary-drugs-applied-to-food-samples-a-review
#4
REVIEW
Gabriela Islas, Israel S Ibarra, Prisciliano Hernandez, Jose M Miranda, Alberto Cepeda
To achieve analytical success, it is necessary to develop thorough clean-up procedures to extract analytes from the matrix. Dispersive solid phase extraction (DSPE) has been used as a pretreatment technique for the analysis of several compounds. This technique is based on the dispersion of a solid sorbent in liquid samples in the extraction isolation and clean-up of different analytes from complex matrices. DSPE has found a wide range of applications in several fields, and it is considered to be a selective, robust, and versatile technique...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/29181026/simple-quantification-of-pentosidine-in-human-urine-and-plasma-by-high-performance-liquid-chromatography
#5
Ji Sang Lee, Yoon-Sok Chung, Sun Young Chang, Yi-Sook Jung, So Hee Kim
Pentosidine is an advanced glycation end-product (AGE) and fluorescent cross-link compound. A simple high-performance liquid chromatographic (HPLC) method was developed for the detection and quantification of pentosidine in human urine and plasma. The mobile phase used a gradient system to improve separation of pentosidine from endogenous peaks, and chromatograms were monitored by fluorescent detector set at excitation and emission wavelengths of 328 and 378 nm, respectively. The retention time for pentosidine was 24...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/29158736/hollow-fibre-supported-dispersive-liquid-liquid-microextraction-for-determination-of-atrazine-and-triclosan-in-aqueous-samples
#6
Thabiso Letseka, Mosotho J George
We report the application of the dispersive liquid-liquid microextraction coupled to hollow-fibre membrane-assisted liquid-phase microextraction and its application for extraction of atrazine and triclosan. Under optimum conditions, namely, 25 μL of a 1 : 4 chlorobenzene : ethyl acetate mixture dispersed in 1 mL of aqueous sample, 10% (m/v) NaCl, a magnetic stirrer speed at 600 rpm, and 10 minutes' extraction time with toluene-filled fibre as the acceptor phase, the method demonstrates sufficient figures of merit...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/29138635/nmr-confirmation-and-hplc-quantification-of-javamide-i-and-javamide-ii-in-green-coffee-extract-products-available-in-the-market
#7
Jae B Park
Javamide-I/javamide-II are phenolic amides found in coffee. Recent reports suggested that they may contain several biological activities related to human health. Therefore, there is emergent interest about their quantities in coffee-related products. Green coffee extract is a powder extract made of unroasted green coffee beans, available as a dietary supplement. However, there is little information about the amounts of javamide-I/javamide-II in green coffee extract products in the market. Therefore, in this paper, javamide-I/javamide-II were extracted from green coffee extract products and their identifications were confirmed by NMR...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/29129976/using-odd-alkanes-as-a-carbon-source-to-increase-the-content-of-nutritionally-important-fatty-acids-in-candida-krusei-trichosporon-cutaneum-and-yarrowia-lipolytica
#8
Olga Matatkova, Lucia Gharwalova, Michal Zimola, Tomas Rezanka, Jan Masak, Irena Kolouchova
We investigated the possibility of utilizing unusual carbon sources by three yeast strains: Candida krusei DBM 2136, Trichosporon cutaneum CCY 30-5-10, and Yarrowia lipolytica CCY 30-26-36. These strains are characterized by high biomass yield, ability to accumulate high amounts of lipids, and their potential as producers of dietetically important fatty acids. The aim of this work was the production of nutritionally important fatty acids by utilization of n-alkanes with an odd number of carbon atoms, alone and in combination with glucose and subsequent analysis of microbial lipids accumulation and fatty acid profile...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/29123548/the-hazard-content-of-cadmium-lead-and-other-trace-elements-in-some-medicinal-herbs-and-their-water-infusions
#9
Fuad A Ababneh
54 samples belonging to 23 herbal species (15 individuals and 8 mixtures) were analyzed for their contents of heavy metals in the raw materials and in their water infusions. Trace and toxic elements in these samples were determined by using inductively coupled plasma-atomic emission spectrometry (ICP-OES) following acid digestion. The order of decreasing mean metal concentrations in raw materials (mg/kg) was found to be as follows: Fe (440) > Mn (162) > Zn (45.8) > Cu (12) > Pb (10.4) > Ni (5...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/29075295/application-of-hptlc-with-densitometry-for-evaluation-of-the-impact-of-external-factors-on-contents-of-diphenhydramine-in-its-solutions
#10
Katarzyna Bober
The subject of durability of drugs is a very important problem investigated by researches. The method of accelerated aging is very often used for stability testing. It involves the influence of temperature, humidity, and light exposure. The aim of this work is estimation of contents of diphenhydramine in its standard solutions undergoing the impact of external factors, that is, temperature and UV light. The standard solutions of diphenhydramine were prepared in distilled water. The analysis of contents of compound investigated was carried out by use of HPTLC...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/29056967/analysis-of-three-compounds-in-flos-farfarae-by-capillary-electrophoresis-with-large-volume-sample-stacking
#11
Hai-Xia Yu, Zeng-Yan Hao, Lu Li, Ya-Yun Huang, Hong-Fen Zhang, An-Jia Chen
The aim of this study was to develop a method combining an online concentration and high-efficiency capillary electrophoresis separation to analyze and detect three compounds (rutin, hyperoside, and chlorogenic acid) in Flos Farfarae. In order to get good resolution and enrichment, several parameters such as the choice of running buffer, pH and concentration of the running buffer, organic modifier, temperature, and separation voltage were all investigated. The optimized conditions were obtained as follows: the buffer of 40 mM NaH2P04-40 mM Borax-30% v/v methanol (pH 9...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/28932243/sensitive-wavelengths-selection-in-identification-of-ophiopogon-japonicus-based-on-near-infrared-hyperspectral-imaging-technology
#12
Zhengyan Xia, Chu Zhang, Haiyong Weng, Pengcheng Nie, Yong He
Hyperspectral imaging (HSI) technology has increasingly been applied as an analytical tool in fields of agricultural, food, and Traditional Chinese Medicine over the past few years. The HSI spectrum of a sample is typically achieved by a spectroradiometer at hundreds of wavelengths. In recent years, considerable effort has been made towards identifying wavelengths (variables) that contribute useful information. Wavelengths selection is a critical step in data analysis for Raman, NIRS, or HSI spectroscopy. In this study, the performances of 10 different wavelength selection methods for the discrimination of Ophiopogon japonicus of different origin were compared...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/28845160/separation-process-of-fine-coals-by-ultrasonic-vibration-gas-solid-fluidized-bed
#13
Shuai Wang, Yaqun He, Hua Wei, Weining Xie
Ultrasonic vibration gas-solid fluidized bed was proposed and introduced to separate fine coals (0.5-0.125 mm fraction). Several technological methods such as XRF, XRD, XPS, and EPMA were used to study the composition of heavy products to evaluate the separation effect. Results show that the ultrasonic vibration force field strengthens the particle separation process based on density when the vibration frequency is 35 kHz and the fluidization number is 1.8. The ash difference between the light and heavy products and the recovery of combustible material obtain the maximum values of 47...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/28835753/phenolics-in-primula-veris-l-and-p-elatior-l-hill-raw-materials
#14
Katarzyna Bączek, Jarosław L Przybył, Małgorzata Mirgos, Olga Kosakowska, Izabela Szymborska-Sandhu, Zenon Węglarz
Primula veris L. and Primula elatior (L.) Hill represent medicinal plants used for the production of herbal teas and preparations with antioxidant and expectorant activity. Flowers and roots of both species possess the same biological activity. In the presented study, raw materials of wild growing P. veris and P. elatior were compared in terms of the content and composition of phenolic compounds using a fast and simple HPLC-DAD method. The study showed that flowers of both species were rich in flavonoids. However, P...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/28831284/effect-of-isopropyl-alcohol-concentration-and-etching-time-on-wet-chemical-anisotropic-etching-of-low-resistivity-crystalline-silicon-wafer
#15
Eyad Abdur-Rahman, Ibrahim Alghoraibi, Hassan Alkurdi
A micropyramid structure was formed on the surface of a monocrystalline silicon wafer (100) using a wet chemical anisotropic etching technique. The main objective was to evaluate the performance of the etchant based on the silicon surface reflectance. Different isopropyl alcohol (IPA) volume concentrations (2, 4, 6, 8, and 10%) and different etching times (10, 20, 30, 40, and 50 min) were selected to study the total reflectance of silicon wafers. The other parameters such as NaOH concentration (12% wt.), the temperature of the solution (81...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/28831283/in-vitro-dissolution-profile-of-dapagliflozin-development-method-validation-and-analysis-of-commercial-tablets
#16
Rafaela Zielinski Cavalheiro de Meira, Aline Biggi Maciel, Fabio Seigi Murakami, Paulo Renato de Oliveira, Larissa Sakis Bernardi
Dapagliflozin was the first of its class (inhibitors of sodium-glucose cotransporter) to be approved in Europe, USA, and Brazil. As the drug was recently approved, there is the need for research on analytical methods, including dissolution studies for the quality evaluation and assurance of tablets. The dissolution methodology was developed with apparatus II (paddle) in 900 mL of medium (simulated gastric fluid, pH 1.2), temperature set at 37 ± 0.5°C, and stirring speed of 50 rpm. For the quantification, a spectrophotometric (λ = 224 nm) method was developed and validated...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/28819360/hexavalent-chromium-removal-from-model-water-and-car-shock-absorber-factory-effluent-by-nanofiltration-and-reverse-osmosis-membrane
#17
Amine Mnif, Imen Bejaoui, Meral Mouelhi, Béchir Hamrouni
Nanofiltration and reverse osmosis are investigated as a possible alternative to the conventional methods of Cr(VI) removal from model water and industrial effluent. The influences of feed concentration, water recovery, pH, and the coexisting anions were studied. The results have shown that retention rates of hexavalent chromium can reach 99.7% using nanofiltration membrane (NF-HL) and vary from 85 to 99.9% using reverse osmosis membrane (RO-SG) depending upon the composition of the solution and operating conditions...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/28791049/effectiveness-of-liquid-liquid-extraction-solid-phase-extraction-and-headspace-technique-for-determination-of-some-volatile-water-soluble-compounds-of-rose-aromatic-water
#18
Hale Seçilmiş Canbay
Steam distillation is used to isolate scent of rose flowers. Rose aromatic water is commonly used in European cuisine and aromatherapy besides its use in cosmetic industry for its lovely scent. In this study, three different sampling techniques, liquid-liquid extraction (LLE), headspace technique (HS), and solid phase extraction (SPE), were compared for the analysis of volatile water-soluble compounds in commercial rose aromatic water. Some volatile water-soluble compounds of rose aromatic water were also analyzed by gas chromatography mass spectrometry (GCMS)...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/28757871/quantification-of-barbatusin-and-3%C3%AE-hydroxy-3-deoxybarbatusin-in-plectranthus-species-by-hplc-dad
#19
Maria Goretti de Vasconcelos Silva, Leandro Bezerra Lima, Maria da Conceição Ferreira de Oliveira, Marcos Carlos de Mattos, Jair Mafezoli
The concentration of diterpenes barbatusin (1) and 3β-hydroxy-3-deoxybarbatusin (2) in the extracts from leaves of Plectranthus grandis, P. barbatus, P. ornatus, and P. amboinicus was evaluated by HPLC-DAD analysis on a Luna C-18 column, using isocratic mixtures of water and acetonitrile as eluents. The regression equations were obtained with good linearity (r(2) > 0.99) and limit of quantifications was higher than 0.1 µg/mL. The precision (lower than 3.5%, within day) and accuracy (higher than 81.7% and lower than 107...
2017: International Journal of Analytical Chemistry
https://www.readbyqxmd.com/read/28751914/geochemical-characteristics-and-origins-of-the-crude-oil-of-triassic-yanchang-formation-in-southwestern-yishan-slope-ordos-basin
#20
Xiaoli Zhang, Jinxian He, Yande Zhao, Hongchen Wu, Zeqiang Ren
Biomarker compounds that derived from early living organisms play an important role in oil and gas geochemistry and exploration since they can record the diagenetic evolution of the parent materials of crude oil and reflect the organic geochemical characteristics of crude oil and source rocks. To offer scientific basis for oil exploration and exploitation for study area, gas chromatography-mass spectrometry method is applied to study the biomarker compounds of crude oil in Southwestern Yishan Slope of Ordos Basin, through qualitatively and quantitatively analyzing separated materials...
2017: International Journal of Analytical Chemistry
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