Distribution Of Chemical Components Research Articles

PAT: From Western solid dosage forms to Chinese materia medica preparations using NIR-CI.

Near-infrared chemical imaging (NIR-CI) is an emerging technology that combines traditional near-infrared spectroscopy with chemical imaging. Therefore, NIR-CI can extract spectral information from pharmaceutical products and simultaneously visualize the spatial distribution of chemical components. The rapid and non-destructive features of NIR-CI make it an attractive process analytical technology (PAT) for identifying and monitoring critical control parameters during the pharmaceutical manufacturing process. This review mainly focuses on the pharmaceutical applications of NIR-CI in each unit operation during the manufacturing processes, from the Western solid dosage forms to the Chinese materia medica preparations. Finally, future applications of chemical imaging in the pharmaceutical industry are discussed.

Method for automatically identifying spectra of different wood cell wall layers in Raman imaging data set.

The technique of Raman spectroscopic imaging is finding ever-increasing applications in the field of wood science for its ability to provide spatial and spectral information about the sample. On the basis of the acquired Raman imaging data set, it is possible to determine the distribution of chemical components in various wood cell wall layers. However, the Raman imaging data set often contains thousands of spectra measured at hundreds or even thousands of individual frequencies, which results in difficulties accurately and quickly extracting all of the spectra within a specific morphological region of wood cell walls. To address this issue, the authors propose a new method to automatically identify Raman spectra of different cell wall layers on the basis of principal component analysis (PCA) and cluster analysis. A Raman imaging data set collected from a 55.5 μm × 47.5 μm cross-section of poplar tension wood was analyzed. Several thousand spectra were successfully classified into five groups in accordance with different morphological regions, namely, cell corner (CC), compound middle lamella (CML), secondary wall (SW), gelatinous layer (G-layer), and cell lumen. Their corresponding average spectra were also calculated. In addition, the relationship between different characteristic peaks in the obtained Raman spectra was estimated and it was found that the peak at 1331 cm(-1) is more related to lignin rather than cellulose. Not only can this novel method provide a convenient and accurate procedure for identifying the spectra of different cell wall layers in a Raman imaging data set, but it also can bring new insights into studying the morphology and topochemistry in wood cell walls.

Multi-layer laser solid forming of Zr65Al7.5Ni10Cu17.5 amorphous coating: Microstructure and corrosion resistance

Abstract Multi-layer Zr 65 Al 7.5 Ni 10 Cu 17.5 amorphous coatings were produced by laser solid forming on A283 substrate. The coatings with few pores and free of cracks had good metallurgical bonding with the substrate. The microstructural characterization, phase composition, chemical component distribution and corrosion behavior of the coatings were investigated. The results revealed that the amorphization degree increased from the substrate to the coating surface mainly due to the dilution and stir influence from the melted substrate. In the five layers coating, the volume fraction of amorphous phase in the 5th layer, 3rd layer and 1st layer was about 77%, 64% and 49% respectively. With regard to corrosion property, potentiodynamic polarization plots, Nyquist plots and the equivalent circuits were employed in 3.5 wt% sodium chloride solution. Attributing to the presence of amorphous phase and passivation, the LSF coatings exhibit excellent corrosion resistance.

The study of the amount of heat release in the sinter charge layer

Based on the data on the chemical composition of charge at the sinter plant MK Zaporizhstal (Ukraine), dependencies, allowing to determine the amount of released and absorbed heat energy per unit volume of the sintered charge by the layer height from the average diameter of the material particles were obtained in the paper. Equations, allowing to calculate the amount of heat energy, released and absorbed per unit volume of the charge as a result of the combustion of the fuel particles and exo- and endothermic reactions, proceeding therein are presented. The results allow a close approach to the problem of the optimization of the thermal regime of the agglocharge sintering process on the author's model, based on finite element method, which takes into account the internal heat release per unit volume, as well as determination of polydisperse charge layer formation laws for rational distribution of fuels and chemical components by the height of the agglomerated layer.

Chemical composition and mass size distribution of PM<sub>1</sub> at an elevated site in central east China

Abstract. Size-resolved aerosol chemical compositions were measured continuously for 1.5 years from June 2010 to January 2012 with an aerosol mass spectrometer (AMS) to characterize the mass and size distributions (MSDs) of major chemical components in submicron particles (approximately PM1) at Mountain Tai (Mt. Tai), an elevated site in central east China. The annual mean mass concentrations of organic, sulfate, nitrate, ammonium, and chloride were 11.2, 9.2, 7.2, 5.8, and 0.95 μg m−3, respectively, which are much higher than those at most mountain sites in the USA and Europe, but lower than those at the nearby surface rural sites in China. A clear seasonality was observed for all major components throughout the study, with low concentration in fall and high in summer, and is believed to be caused by seasonal variations in planetary boundary layer (PBL) height, near surface pollutant concentrations and regional transport processes. Air masses were classified into categories impacted by PBL, lower free troposphere (LFT), new particle formation (NPF), in-cloud processes, and polluted aerosols. Organics dominated the PM1 mass during the NPF episodes, while sulfate contributed most to PM1 in cloud events. The average MSDs of particles between 30 and 1000 nm during the entire study for organics, sulfate, nitrate, and ammonium were approximately log-normal with mass median diameters (MMDs) of 539, 585, 542, and 545 nm, respectively. These values are slightly larger than those observed at ground sites within the North China Plain (NCP), likely due to the relative aged and well-mixed aerosol masses at Mt. Tai. There were no obvious differences in MMDs during the PBL, LFT, in-cloud and polluted episodes, but smaller MMDs, especially for organics, were observed during the NPF events. During the PBL, NPF, and polluted episodes, organics accounted for major proportions at smaller modes, and reached 70% at 100–200 nm particles in the polluted events. In cloud episodes, inorganics contributed 70% to the whole size range dominated by sulfate, which contributed 40% to small particles (100–200 nm), while organics occupied 20%, indicating that sulfate is a critical chemical component in cloud formation. Seven clusters of air masses were classified based on 72 h back-trajectory analysis. The majority of the regionally dispersed aerosols were found to be contributed from short distance mixed aerosols, mostly originated from the south with organics and sulfate as major components. Air masses from long range transport always brought clean and dry aerosols which resulted in low concentrations at Mt. Tai. AMS-PMF (positive matrix factorization) was employed to resolve the subtype of organics. Oxygenic organics aerosols (OAs) occupied 49, 56, 51, and 41% of OAs in the four seasons respectively, demonstrating that most OA were oxidized in summer due to strong photochemical reactions. Biomass burning OAs (BBOAs) accounted for 34% of OA in summer, mainly from field burning of agriculture residues, and coal combustion OAs (CCOAs) accounted for 22% of OA in winter from heating.

Chemical imaging and solid state analysis at compact surfaces using UV imaging

Fast non-destructive multi-wavelength UV imaging together with multivariate image analysis was utilized to visualize distribution of chemical components and their solid state form at compact surfaces. Amorphous and crystalline solid forms of the antidiabetic compound glibenclamide, and microcrystalline cellulose together with magnesium stearate as excipients were used as model materials in the compacts. The UV imaging based drug and excipient distribution was in good agreement with hyperspectral NIR imaging. The UV wavelength region can be utilized in distinguishing between glibenclamide and excipients in a non-invasive way, as well as mapping the glibenclamide solid state form. An exploratory data analysis supported the critical evaluation of the mapping results and the selection of model parameters for the chemical mapping. The present study demonstrated that the multi-wavelength UV imaging is a fast process analytical technique with the potential for real-time monitoring of critical quality attributes.

Evaluation of the Quality of Angelica sinensis by High-Performance Liquid Chromatography

Quality control and consistent quality are prerequisites to guarantee the safety and efficacy of pharmaceutical preparations and dietary supplements. In this paper, the intra- and inter-annual consistency and stability of Angelica sinensis (Oliv.) Diels, cultivated according to Good Agricultural Practices (GAP) in the main production areas of China, were evaluated by high-performance liquid chromatographic fingerprints composed of twenty-four common components. Subsequently, thirteen compounds were identified in the chromatograms using diode array detection and mass spectrometry. Z-Ligustilide, senkyunolide H, senkyunolide I, and ferulic acid were determined to evaluate the distribution of chemical components. In addition, robust principal component analysis was applied to further evaluate the samples, and four discriminatory “markers” among the common twenty-four were pinpointed by the loading plots that were used to distinguish quality differences of Angelica sinensis from different harvest years.

Analysis of the Distribution of Chemical Compounds from Fly Ash Exposed to Weather Conditions

Abstract The paper presents investigation results of the migration of a chemical compound contained in fly ash deposited on a dry furnace waste landfill site exposed to weather conditions. Climate conditions are able to significantly affect chemical component distribution in a block of deposited, moving chemical compounds to different depths. The main aim of the investigations was to determine the chemical component distribution of deposited fly ash in the landfill. Identification of chemical components based on XRF analysis indicated the existence of differences in both tested storage layer and the fraction of fly ash.

Chemical evidence for the origin of the cold water belt along the northeastern coast of Hokkaido

In the southwestern Okhotsk Sea, the cold water belt (CWB) is frequently observed on satellite images offshore of the Soya Warm Current flowing along the northeastern coast of Hokkaido, Japan, during summertime. It has been speculated that the CWB is upwelling cold water that originates from either subsurface water of the Japan Sea off Sakhalin or bottom water of the Okhotsk Sea. Hydrographic and chemical observations (nutrients, humic-type fluorescence intensity, and iron) were conducted in the northern Japan Sea and southwestern Okhotsk Sea in early summer 2011 to clarify the origin of the CWB. Temperature–salinity relationships, vertical distributions of chemical components, profiles of chemical components against density, and the (NO3 + NO2)/PO4 relationship confirm that water in the CWB predominantly originates from Japan Sea subsurface water.

The synthesis of core-shell monodisperse P(St-MAA) microspheres and fabrication of photonic crystals Structure with Tunable Colors on polyester fabrics

The core-shell monodisperse P(St-MAA) microspheres with different diameters ranging from 200 nm to 400 nm were prepared by soap-free emulsion copolymerization, in which styrene (St) and methacrylic acid (MAA) were polymerizable monomers, and ammonium persulfate (APS) acted as initiator. The diameters and monodispersity of P(St-MAA) microspheres could be controlled by adjusting the concentrations of styrene, methacrylic acid and ammonium persulfate. The core-shell structure and chemical component distribution of the P(St-MAA) microspheres were confirmed by TEM and XPS. The photonic crystals on polyester fabrics with three-dimensionally ordered arrangement were fabricated by self-assembly of gravitational sedimentation with P(St-MAA) microspheres and exhibited brilliant structural colors without any chemical dyes and pigments. SEM, TEM and crystallographic analysis were applied to confirm a face centered cubic (fcc) structure of the photonic crystals on polyester fabrics. The versatile structural colors of the photonic crystals were dependent on the photonic band-gap which could be regulated by the spherical size of P(St-MAA) microspheres and viewing angles. This technology may provide a new strategy to color the fabrics and reduce the pollution in the current textile industry.

Impact of Alkali Pretreatment on the Chemical Component Distribution and Ultrastructure of Poplar Cell Walls

Alkali pretreatment is one of the leading pretreatment technologies for biofuel applications. The histochemical and structural characteristics of poplar cell walls were investigated before and after sodium hydroxide pretreatment (121 oC, 2%) to understand the alterations in biomass cellular structure, which were correlated with saccharification yield. Results showed that alkali pretreatment preferentially removed lignin from the S2 of fibers, which was similar to the behaviors of coniferyl alcohol and aldehyde (lignin-CAA), exhibiting a positive correlation between removal of the two structures. Additionally, the cellulose microfibril angle was enlarged as the residence time increased during pretreatment. Scanning electron microscopy (SEM) analysis further suggested that pretreatment caused ultrastructure changes in cell walls with cracks formation on cell wall surface, especially in the areas adjacent to the cell corner middle lamellar (CCML). Accordingly, the cellulose digestibility of residues increased from 32.1% for the raw material to 53.7% for the treated samples obtained in 72 h. It can be concluded that the changes in topochemistry and ultrastructure of poplar cell walls resulting from alkali pretreatment mediated the efficiency of enzymatic hydrolysis of residues.

The Raw Material Sources and Nondestructive Identification Study of the Blue and White Porcelain Made in Jiajing Official Kiln and Dehua Housuo Kiln

In order to study the raw material sources and their identification methods of blue and white porcelain made in Jingdezhen Jiajing official kiln (J-O-kiln) and Dehua Housuo kiln (D-H-kiln), 22 blue and white porcelain samples of J-O-kiln and D-H-kiln were analyzed for their body and glaze chemical compositions by Proton Induced X-Ray Emission (PIXE). A set of fingerprint chemical components among them were selected for distribution analysis. Our results show that the raw material sources the porcelain bodies of J-O-kiln are relatively concentrated, and those of D-H-kiln porcelain bodies are relatively scattered, and the raw material sources of porcelain bodies made in the two kilns are quite different, and the raw material sources, recipes of the transparent glazes and blue and white glazes made in these two kilns are also quite different. Therefore, blue and white porcelain samples from J-O-kiln and D-H-kiln can be better easily differentiated by PIXE and fingerprint chemical components distribution analysis.

Studies on paint cross sections of a glass painting by using FT‐IR and Raman microspectroscopy supported by univariate and hierarchical cluster analyses

Fourier transform infrared (FT‐IR) and Raman spectroscopy is used for the non‐destructive analysis of painting materials and ageing compounds in micrometric cross sections of a glass painting. The combination of both techniques in conjunction with imaging/mapping function provides the spatial distribution of chemical components identified in vibrational spectra. The aim of our work is to show the applicability of the FT‐Raman mapping technique in the detection of painting materials. We also compare Raman information gained by using two laser excitations at 532 and 1064 nm implemented in microspectrometers with different confocality and spatial resolution. In turn among FT‐IR imaging techniques, we compare chemical images recorded in external reflection and attenuated total reflection modes that give chemical images of different size and spatial resolution. Our FT‐IR and Raman imaging characterize a number of painting materials such as pigments, binders, fillers as well as degradation products. Raman maps are constructed by using the univariate analysis. In turn, a profile of IR images requires the use of a more complex methodology. Here, we compare FT‐IR images of the painting cross sections obtained by using the univariate and hierarchical cluster analysis. We clearly show that the multivariate approach is a powerful tool for the credible construction of IR images, providing the relevant chemical information on the multicomponent stratigraphy of the samples. Moreover, the combination of all the methods allows us to demonstrate their degree of utility for the study on the paint cross sections of the works of art. Copyright © 2013 John Wiley & Sons, Ltd.

Size distribution of water-soluble components in particulate matter emitted from biomass burning

Size-resolved measurements of particulate matter (PM) emissions from 10 biomass materials (rice straw, soybean stem, green perilla stem, red pepper stem, pine needles, cherry leaves, cherry stem, maple leaves, gingko leaves and gingko stem) were conducted in a laboratory hood chamber environment using a 10-stage MOUDI. Samples were analyzed to determine the mass, water soluble organic carbon (WSOC), and water soluble inorganic species. This study examines how particle emissions and size distributions of chemical components vary with biomass materials. Mass fractions of water soluble organic mass (WSOM) (=1.6 × WSOC) and ionic species to the PM1.8 emissions varied significantly depending on the biomass type burned. The percent mass of WSOM in PM1.8 emissions ranged from 19.8% (green perilla stem) to 41.9% (red pepper stem) for agricultural crop residues, while the tree category accounted for 9.6% (gingko leaves) to 44.0% (gingko stem) of the PM1.8 emissions. Total ionic species contents in the PM1.8 mass ranged from 7.4% (rice straw) to 26.9% (green perilla stem) for the agricultural waste category, and 5.8% (maple leaves) to 23.5% (gingko stem) for the tree category. The ionic species fraction of the PM1.8 emission was dominated by K+, Cl−, and SO42−, while Ca2+ was important in the coarse mode particles (>3.1 μm). PM1.8 emissions of K+, Cl−, and SO42− were as high as 16.9%, 9.0%, and 5.8%, respectively, and were from the green perilla stem, red pepper stem, and gingko stem emissions.Normalized size distributions of mass, WSOC, K+, Cl−, SO42−, and oxalate in the biomass burning emissions showed a unimodal size distribution, peaking in the size ranges of 0.32–0.55 μm and 0.55–1.0 μm. Size-resolved PM mass fractions of WSOM, K+, Cl−, and SO42− showed fairly consistent distributions for each biomass type, with higher fractions in the ultrafine mode (<0.10 μm) and lower fractions in the accumulation mode of 0.32–1.0 μm. The size distributions of WSOC were strongly correlated (mostly R2 > 0.90) with those of K+ in the particle size range of <0.1 μm and 0.1–1.8 μm and the biomass types. Strong correlations between the concentrations of K+–Cl− and K+−SO42− were observed for the following size ranges; <0.1 μm, 0.1–1.0 μm, 1.0–1.8 μm, and 1.8–3.1 μm for most biomass burning emissions. Regression line slopes for K+/WSOC (i.e., mass of K+/mass of WSOC from biomass burning emissions) were not significantly changed for particle size and biomass type, but slopes for Cl−/K+ and SO42−/K+ varied significantly with the particle size (ultrafine, condensation, droplet, and coarse modes) and biomass type.

Characterization of black carbon in geosorbents at the nanometer scale by STEM–EDX elemental mapping

The lack of a universal method for black carbon (BC) quantification and the need to describe the intra-particle/aggregate distribution of BC in natural matrices/geosorbents prompted the search for new methods. This study explored the feasibility of using analytical electron microscopy to characterize black carbon residing in natural matrices. Soot, char, graphite and other carbonaceous samples were examined using energy dispersive X-ray (EDX) analysis in transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). TEM–EDX analysis (point analysis) showed that char, soot and graphite all have a characteristic O/C atomic ratio of ⩽ 0.1 when interrogated at the submicrometer scale, implying this BC elemental signature may be useful in identifying BC at this scale. The presence of a universal elemental signature suggested that it may be more proper to describe different condensed carbonaceous materials as having different BC contents, rather than emphasizing that there are different types of BC, each with a different bulk characteristic O/C. Subsequently, the mapping of BC in STEM–EDX (areal analysis) was demonstrated on sediment samples with varying soot content at a resolution of ∼10nm. Several standard carbonaceous materials were also examined with quantitative STEM–EDX, yielding BC content comparable with other conventional BC quantification methods. The power of STEM–EDX in revealing morphological features and distribution of various chemical components at nanometer scale was also highlighted. The analytical approach presented here will be valuable for the characterization of BC and the study of nanometer scale organic-mineral association in sediments and soils.

中部山岳地域の降雪に含まれる化学成分濃度の空間分布

中部山岳地域の降雪に含まれる化学成分濃度の空間分布

Application of infrared spectroscopic imaging in specular reflection mode for determination of distribution of chemical components in urinary stones

Distribution of chemical components in the mixed oxalatic, phosphatic and uratic urinary stones was analysed by means of infrared microspectroscopy. The specular reflection from the surface of the cross-sectioned stones was used for the infrared spectroscopic imaging. It was found that the reflection spectra consist from specular and diffuse reflection components and the former one exhibit Reststrahlen bands which resemble first derivative of the spectral bands in the absorption spectrum. In order to use the measured spectra for the chemical imaging they were corrected for asymmetry by subtracting the diffuse reflection component and applying Kramers–Kronig transform to the specular reflection component. The Kramers–Kronig transformed spectrum was then combined with the diffuse reflection component. Spectra corrected in this manner were used to create false-colour images of the stones. It was found that the images obtained after applying the correction procedure to the spectra differ substantially from the ones obtained from the raw spectra. They are in good agreement with the stones’ images obtained from the FT-Raman spectra.

Investigation of the distribution of chemical components in selected landfill layers and fly ash fractions

Investigation of the distribution of chemical components in selected landfill layers and fly ash fractions The article concerns fly ashes generated from the combustion of hard coal and deposited on landfills. Investigation results describing fly ash taken from a combustion waste landfill are presented in the article. The investigation results indicate a possibility for combusting the coal reclaimed by separation from the fly ash and utilizing the remaining fly ash fractions.

Quantitative surface plasmon spectroscopy: Determination of the infrared optical constants of living cells

Fourier transform infrared (FTIR) spectroscopy gives a great amount of information on the distribution of chemical components in biological objects, in particular cells, in a label-free manner. We report on the development of the spectroscopic technique that combines the surface plasmon resonance (SPR) and the FTIR. Our method is based on the original processing of SPR measurements at varying angles and wavelengths and yields the complex refractive index of the analyte in a broad wavelength region. Contrary to previous SPR studies which yielded information about refractive index variation only, our technique gives absolute optical constants of the examined medium. Using this approach, we studied living Madin Darby canine kidney (MDCK) epithelial cells cultured in their natural aqueous environment and measured their optical constants. We showed that our technique has the ability to distinguish absorption lines of certain chemical components of the cells, such as the absorption lines of a CHn bonds which are characteristic mostly for cell membrane lipids.

The fabrication and investigation of n/CdS-p/CdTe-n/Si structures

Attempts to obtain heterojunctions between A2B6 (cadmium telluride and cadmium sulfide) compounds and silicon were made. The distributions of chemical components and some photoelectric properties of the surfaces of the produced layers were investigated.