Quantitative phase analysis and molecular structure of human gallstones using synchrotron radiation X-ray diffraction and FTIR spectroscopy.

Human gallstones are the most common disorder in the biliary system, affecting up to 20 % of the adult population. The formation of gallstones is primarily due to the supersaturating of cholesterol in bile. In order to comprehend gallstone disease in detail, it is necessary to have accurate information about phase identification and molecular structure. Different types of gallstone samples were collected from the Middle East area after surgical operations including; cholesterol, pigment, and mixed gallstones. To estimate the basic information about the stone formation and the pathophysiology of cholelithiasis as well as to classify the collected human gallstones, attenuated total reflection Fourier transform Infrared spectrometry (ATR-FTIR) was used to analyze the different gallstone structures in the wavenumber range from 400 to 4000 cm-1. Calcium bilirubinate was specified by the bands at 1662 cm-1, 1626 cm-1, and 1572 cm-1, while cholesterol rings were designated by the bands at 1464, 1438, 1055, and 1022 cm-1. It can be assumed that all samples consist of mixed gallstones based on the doublets at 1375 cm-1 and 1365 cm-1. The levels of calcium bilirubin and various minerals varied among the analyzed samples, indicating the heterogeneity in their composition and suggesting potential implications for gallstone formation. Based on the quantitative phase analysis using synchrotron radiation X-ray diffraction (SR-XRD), two phases of anhydrous cholesterol as a major content and one phase of monohydrate cholesterols as trace content represent the main components of most of the gallstones. Additional phases of calcium carbonate in the form of calcite, vaterite, aragonite, and bilirubinate were also quantified. According to the outcomes of the FTIR and the SR-XRD measurements, there exists a statistical correlation between the different types of chemical constituents of the gallstones.

Temporal and Spatial Variations of Potentially Toxic Elements in PM10 Collected in Jeddah City, Saudi Arabia.

Air pollution causes environmental and health problems around the world. In this study, ambient particulate matter with an aerodynamic diameter equal to or less than 10 microns (PM10) has been collected at three different locations in Jeddah city, Saudi Arabia. The locations are characterized by differences in terms of traffic, residential intensity, industrial, and non-road mobile machinery activities. The monthly and annual mass concentration of the PM10 exceeds the recommended annual limit of the World Health Organization (15 µg/m3) and the European air quality standard (40 µg/m3) at the three locations. The collected PM10 samples as well as a certified reference material of atmospheric particulates (NIST 1678a) were digested in aqua regia using microwave digestion. The quantitative elemental analysis was carried out using inductively coupled plasma mass spectrometry. The variations of the elemental concentration in terms of workdays, weekends, seasons, and annual were determined at the three locations. The spatial and temporal elemental variations were found to be different between the three sites, pointing to local influences that should be further evaluated. The concentration of Cd was found to be high and may cause health problems.

Synthesis of Cyano-Benzylidene Xanthene Synthons Using a Diprotic Brønsted Acid Catalyst, and Their Application as Efficient Inhibitors of Aluminum Corrosion in Alkaline Solutions.

Novel cyano-benzylidene xanthene derivatives were synthesized using one-pot and condensation reactions. A diprotic Brønsted acid (i.e., oxalic acid) was used as an effective catalyst for the promotion of the synthesis process of the new starting xanthene-aldehyde compound. Different xanthene concentrations (ca. 0.1-2.0 mM) were applied as corrosion inhibitors to control the alkaline uniform corrosion of aluminum. Measurements were conducted in 1.0 M NaOH solution using Tafel extrapolation and linear polarization resistance (LPR) methods. The investigated xanthenes acted as mixed-type inhibitors that primarily affect the anodic process. Their inhibition efficiency values were enhanced with inhibitor concentration, and varied according to their chemical structures. At a concentration of 2.0 mM, the best-performing studied xanthene derivative recorded maximum inhibition efficiency values of 98.9% (calculated via the Tafel extrapolation method) and 98.4% (estimated via the LPR method). Scanning electron microscopy (SEM) was used to examine the morphology of the corroded and inhibited aluminum surfaces, revealing strong inhibitory action of each studied compound. High-resolution X-ray photoelectron spectroscopy (XPS) profiles validated the inhibitor compounds' adsorption on the Al surface. Density functional theory (DFT) and Monte Carlo simulations were applied to investigate the distinction of the anticorrosive behavior among the studied xanthenes toward the Al (111) surface. The non-planarity of xanthenes and the presence of the nitrile group were the key players in the adsorption process. A match between the experimental and theoretical findings was evidenced.

Seasonal Variability of Elemental Composition and Phytochemical Analysis of Moringa oleifera Leaves Using Energy-Dispersive X-ray Fluorescence and Other Related Methods.

The elemental contents and the phytochemical components of Moringa oleifera are crucial for nutrition and medical purposes. Therefore, the monthly and seasonal variations of the elemental composition and phytochemical analysis of Moringa oleifera leaves collected from the same ecological area have been investigated. For this purpose, Moringa oleifera leaves were collected monthly from the same tree's branches during the whole year from January 2019 to December 2019. A non-destructive elemental analysis technique was used, namely energy-dispersive X-ray fluorescence spectrometry. The seasonal variations are different from one season to another. The highest concentrations of Mo, Cr, Fe, Ti, and Si were found during winter, whereas the highest concentrations of Br, Cl, and Cu were found during the summer seasons. Based on Pearson's correlation analysis, a strong correlation between Ca and Sr was found, whereas Sr has a negative correlation with other detected elements. Similarly, Cu and Zn as well as Br and Cl have a strong correlation. Remarkable different concentrations were found during May which has the lowest positive correlation. The phytochemical analysis revealed that Moringa oleifera leaves collected during the spring season resulted in the highest chlorophyll content, phenol content, and the greatest scavenging activity. Therefore, the mineral contents and phytochemical compounds are affected by the changing of the seasons of the year. Collectively, the current results are useful for optimizing the harvest time of Moringa oleifera leaves with respect to the quality.

Spectroscopic Characterization of Urinary Stones Richening with Calcium Oxalate.

Intact and non-intact urinary stones richening with calcium oxalate were collected and characterized. The elemental analysis, phase quantifications, and function groups were determined by different spectroscopic techniques, namely: energy-dispersive X-ray fluorescence (EDXRF), the synchrotron radiation X-ray diffraction (SR-XRD), and attenuated total reflection Fourier transform infrared (ATR-FTIR). The quantitative analysis of twenty elements was demonstrated in the most of the urinary stones and these elements are: Ca, Na, P, S, Mg, Cl, Zn, K, Ti, Sr, Ni, Co, Fe, Cu, Cd, Br, Pb, Se, I, and Mn. Using the Rietveld method, the diffraction phase quantification was illustrated. The main found phases are calcium oxalate (monohydrate and dihydrate) and hydroxyapatite phase. The FTIR outcomes reveal that the functional groups of O-H, N-H, C=O, and C-O indicate to the calcium oxalate whereas the P-O and O-P-O, and PO43- groups indicate to the calcium phosphates in the hydroxyapatite. A considerable correlations between the oxalate urinary stones and the group of elements were found. These elements are Zn, Sr, Ni, and Fe. These correlations could lead to new therapeutic approaches. Furthermore, the elements of sodium and chlorine have no vital role in the formation of calcium oxalate urinary stones.

The challenges of Se quantification in bean samples using line and continuum sources atomic absorption spectrometry.

This work demonstrates the challenges for selenium (Se) determination in bean samples using high-resolution continuum source Graphite Furnace Atomic Absorption Spectrometry (HR-CS-GF-AAS) and line source Graphite Furnace Atomic Absorption Spectrometry (LS-GF-AAS). Different chemical modifiers were optimized namely; Ir, Ru, and Pd/Mg nitrates. At selenium contents <5 ng g-1, it cannot be quantified accurately. Spectral interferences of the molecular bands of PO and NO as well as the iron lines with Se line at 196.026 were demonstrated. The noticeable low energy of the continuum source of the HR-CS-GF-AAS at 196.026 nm gives high values of the limits of detection and quantification. The Se limits of detection were found to be 24, 33, and 29 ng g-1 for Ir, Ru, and Pd/Mg modifiers, respectively. In situ trapping hydride generation LS-GF-AAS gives better limits of detection and it reached 30 pg g-1 with Ir modifier.

Spectroscopic Assessment of Platinum Group Elements of PM10 Particles Sampled in Three Different Areas in Jeddah, Saudi Arabia.

Platinum group elements (PGE) including Ru, Rh, Pt and Pd have been quantified in air particulate matter with an aerodynamic diameter equal or less than 10 microns (PM10) using inductively coupled plasma mass spectrometry (ICP-MS). PM10 aerosols have been collected from three sites representing various activities in Jeddah city, Saudi Arabia. These locations are residential site with heavy traffic, industrial site and heavy traffic and a light traffic site outside the city. To obtain reasonable data of the PGE concentrations, a group from 10 to 15 PM10 samples were collected every month. The annual and seasonal variation of the mass concentration of the PGE were demonstrated. In all locations, Pt and Pd were relatively higher than Ru and Rh possibly because their main use is in automobile catalytic converters. Concentrations of observed PGE in PM10 could be arranged in ascending order as: Rh < Ru < Pd < Pt. In case of Ru and Pt, there are clear similarities in terms of the overall mean concentrations at the sampling locations. Due to the high concentration of Ru, Rh and Pd at low traffic site, there are certainly other sources of these elements rather than vehicle catalytic converters. However, at the industrial/heavy traffic location, high concentrations of Ru were detected during February 2015. In addition, high Pt concentrations were also detected at the light traffic site during May 2015. Results indicate that Pt source in PM10 is mainly the automobile catalytic converters.

Development of biological macroalgae lignins using copper based metal-organic framework for selective adsorption of cationic dye from mixed dyes.

The chemical compositions of macroalgae are protein; cholesterol, fatty acid, and lignin which mostly construct from hydroxyl and amine groups. The lignin as a key structure in the tissues of macroalgae was modified using the sulfation pathway. A novel environmental friendly adsorbent Cu-BTC@Algal was synthesized by incorporated Cu-BTC nanoparticles onto sulphated-Macroalgae biomass under solvothermal conditions and characterized by XRD, FTIR, and N2 adsorption-desorption isotherms. The removal rate of Cu-BTC@Algal was quite greater than that of Cu-BTC, showing that the adsorption performance of porous Cu-BTC can be improved through the modification of algal. Further study revealed that Cu-BTC@Algal exhibited a fast adsorption rate and selective adsorption ability towards the cationic dyes in aqueous solution. The removal rate was up to 97% for cationic dyes methylene blue (MB) and 68% for methyl orange (MO) at intervals 10 min. The influences including initial concentration, and contact time of MB/MO adsorption onto modified algal biomass, Cu-BTC and Cu-BTC@Algal were investigated in detail. The kinetic study indicated that the adsorption of MB/MO onto Cu-BTC@Algal followed the pseudo second-order model. The isotherm obtained from experimental data fitted the Langmuir model, yielding maximum adsorption capacity of 42, 73 and 162 mg g-1 for algal, Cu-BTC and Cu-BTC@Algal, respectively.

Applicability of Low-Cost Binders for the Quantitative Elemental Analysis of Urinary Stones Using EDXRF Based on Fundamental Parameter Approach.

The pressed powder sample is a common method for elemental analysis using X-ray fluorescence analysis whereas suitable light hydrocarbon materials should be added to the sample as a binder. The present study demonstrates the applicability of using different commercial binders for elemental analysis of urinary stone samples. In order to confirm the obtained results, a comparison with pure chemical grade binders was presented. Different commercial and pure binders were tested for quantitative elemental analysis of urinary stones, namely, cellulose, starch, wax, and urea. Energy dispersive X-ray fluorescence (EDXRF) was used for elemental analysis. Differential thermal analysis was used to estimate the loss on ignition (LOI) in the urinary stone samples. The signal to background ratios (I/IB) of the different detected elements in the commercial and pure binders were calculated, compared, and studied at eight different photon energies starting from 2.5 up to 37 keV. Standard-less quantitative analysis method based on the fundamental parameter approach was applied for elemental analysis of selected urinary stones. The commercial and low-cost binders could be an excellent alternative binder for urinary stone analysis using energy dispersive X-ray fluorescence. The commercial binders could provide an advantage as pure chemical grade binders or even better especially at photon energy higher than 10 keV. The best commercial binder candidate was found to be the wax. The quantitative analysis results using commercial and pure chemical grade binders give good agreement results, which indicate the applicability of commercial binders for quantitative elemental analysis of urinary stones in the form of pressed powder samples.

Elemental Composition of PM2.5 Aerosol in a Residential-Industrial Area of a Mediterranean Megacity.

Very little is known about the elemental composition and possible sources of fine aerosol particles from Mediterranean megacities. Fine aerosol particles were collected at a residential-industrial area in Greater Cairo, Egypt, during the period from October 2010 to May 2011. The elemental compositions of the collected samples were quantified by using a homemade energy dispersive x-ray fluorescence spectrometer, whereas black carbon was quantified by a black smoke detector. Fifteen elements have been quantified. Of these constituents, Ca, C, Cl, S, and Fe had the highest concentrations: greater than 1 µg m-3. The overall mean mass concentration of the collected samples equals 70 µg m-3; this value exceeds the European Union annual Air Quality Standard levels. The individual elemental concentrations of the fine particles were found to be dominated by elements linked to mineral dust. Most of the monthly variations of elemental concentrations can be attributed to seasonal meteorological conditions. Other possible sources were vehicle-exhaust and industrial activities. The results pinpoint the problem of identifying different sources when one source, in this case, the nearby deserts, is dominant. The results from this study contribute to the growing knowledge of concentrations, composition, and possible sources of ambient fine particulate matter.

Influence of Niobium Pentoxide Particulates on the Properties of Brushite/Gelatin/Alginate Membranes.

Novel nonporous membranes were prepared by impregnating brushite and niobium pentoxide (Nb2O5) into a gelatin/alginate matrix. The physicochemical properties, morphology, and mechanical properties of the prepared membranes were characterized using X-ray diffractometer, FTIR spectroscopy, scanning electron microscopy, transmission electron microscopy, and universal testing machine, respectively. Swelling ability of the prepared membranes was determined in distilled water. The surfaces of the membranes were characterized by means of FTIR spectroscopy and scanning electron microscopy coupled with energy dispersive x-ray spectroscopy after submersion in simulated body fluid up to 15 days. Moreover, the calcium and phosphorus ion concentrations in the simulated body fluid were measured using an UV spectrophotometer. The in vitro drug release and the release mechanism of a model antibiotic, namely, ciprofloxacin (CFX), were tested in phosphate-buffered saline for 15 days. The antibacterial activities of the CFX-loaded membranes were tested against known microorganisms. The physicochemical properties, morphology, mechanical properties, and swelling ability of the prepared membranes were found to be dependent on the presence of Nb2O5 allowing control of their properties. For example, the Nb2O5-loaded membranes exhibited a higher in vitro bioactivity and slower drug release compared to those of Nb2O5-free membranes. The CFX-loaded membranes also exhibited an excellent inhibition zones against the selected microorganisms. Overall, the prepared membranes have been found to be very promising for use in bone substitute applications.

Levels of Trace Elements in Black Teas Commercialized in Saudi Arabia Using Inductively Coupled Plasma Mass Spectrometry.

The present work has been demonstrated a developed method for the determination of Mn, Fe, Co, Ni, Cu, Zn, Mo, Cd, As, Cr, Pb, and V in different types of black teas collected from Saudi Arabia market using inductively coupled plasma mass spectrometry (ICP-MS). Each sample represents a well-mixed combination of ten packets from the same type collected from the market. Detection limits in ng g-1 were 76.06, 166.03, 5.94, 2.94, 18.29, 18.29, 9.00, 0.48, 0.48, 7.67, 3.07, and 4.21 for Mn, Fe, Co, Ni, Cu, Zn, Mo, Cd, As, Cr, Pb, and V, respectively. In order to validate the developed method, a certified reference material of green tea was analyzed. Further comparison with the results obtained from high-resolution continuum source atomic absorption spectrometry (HR-CS-AAS) was demonstrated. The obtained good agreement confirms the validity of the investigated method. Fortunately, the concentrations of the heavy metals locate on the range of the international values. The highest metal content was found in Al-Rabee tea, and this type results should be confirmed by using a large number of samples in order to have satisfied and confirmed statistical analysis results.

Spectroscopic Characterization of Dust-Fall Samples Collected from Greater Cairo, Egypt.

This work aimed to characterize dust-fall samples collected from street's trees in Greater Cairo (GC), Egypt, and its surroundings by different spectroscopic techniques, namely; X-ray diffraction (XRD), attenuated total-reflection Fourier transform infrared (ATR-FTIR), particle-size analyzer, and scanning electron microscopy (SEM) combined with energy dispersive X-ray measurements. Samples were collected from 19 different locations inside and outside of GC. Quantitative phase analysis of the dust-fall samples was performed using the Rietveld method. Results showed that the most frequently observed phases in the dust-fall samples were calcite (CaCO3), dolomite (CaMg(CO3)2), gypsum (CaSO4·2H2O), and quartz (SiO2) with average concentrations of 39 ± 16, 8 ± 7, 22 ± 13, and 33 ± 14 wt%, respectively. The occurrence of these constituents referred to a combination of different anthropogenic and natural sources. The ATR-FTIR results are in good agreements with XRD data of the different observed phases. Based on the SEM and particle-size measurements, quantitative determination of the particle-size distribution was described. It was found that not only the large-sized particles are deposited but also the small-sized ones (PM10 and PM2.5). In addition, the particle size of the collected dust-fall samples varied from 0.1 to 200 µm with an average particle size of 17.36 µm; however, the particle size ranged from 2.5 to 40 µm predominated in all of the dust-fall samples.

WITHDRAWN: The challenges of selenium determination in biological samples with graphite furnace using line source and high resolution continuum source atomic absorption spectrometry.

This article has been withdrawn at the request of the author. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Determination of rare earth elements in dust deposited on tree leaves from Greater Cairo using inductively coupled plasma mass spectrometry.

This work aims at monitoring the rare earth elements (REEs) and Th in dust deposited on tree leaves collected inside and outside Greater Cairo (GC), Egypt. Inductively coupled plasma mass spectrometry (ICP-MS) was employed. The concentration of REEs in the collected dust samples was found to be in the range from 1 to 60 µg g(-1). The highest concentration of REEs was found in dust samples collected outside GC, in the middle of the Nile Delta. This would refer to the availability of black sands, due to desert wind occurrence during the sample collection, and anthropogenic activities. The limits of detection of the REEs ranged from 0.02 ng g(-1) for Tm to 3 ng g(-1) for Yb. There was an obvious variation in the concentration of REEs inside and outside GC due to variations of natural and anthropogenic sources. Strong correlations among all the REEs were found.

Comparison of three different sample preparation procedures for the determination of traffic-related elements in airborne particulate matter collected on glass fiber filters.

Three different procedures for sample preparation have been compared for the determination of Cu, Mo and Sb in airborne particulate matter (APM) collected on glass fiber filters using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS). Direct solid sample analysis of the ground filters was compared with microwave-assisted acid leaching with aqua regia and ultrasound-assisted extraction also using aqua regia. The main absorption line at 324.754 nm or the secondary line at 216.509 nm was used for the determination of Cu, depending on the analyte content in the samples. The primary absorption line at 313.259 nm was used for Mo and the secondary line at 212.739 nm for Sb determination. The limits of detection (LOD, 3σ) found for the direct solid sampling method, based on ten atomizations of an unused filter were 15 µg g(-1) for all three analytes, corresponding to 40 ng m(-3) for a typical air volume of 1,440 m(3) collected over a period of 24h. The LOD for the other two methods were less than a factor of two inferior, but the total time required for an analysis was significantly longer. The repeatability of the measurements was between 3 and 9% (n=5), and the results obtained with the three methods did not show any significant difference. The ratio between the three analytes on the filters from areas of intense traffic was found to be around Cu:Mo:Sb≈4:1:1.4, which suggests that the source of all three elements is brake linings, i.e., related to automobile traffic. When the ratio deviated significantly from the above values, the source of contamination was assumed to be of different origin.

FTIR spectroscopic, thermal and XRD characterization of hydroxyapatite from new natural sources.

The inorganic constituents of 5 different plants (leaves and stalks) were investigated by using Fourier transformer infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermal analysis including thermal gravimetric analysis (TGA), derivative thermogravimetry (DTG) and differential scanning calorimetry (DSC). These plants are Catha edulis (Khat), basil, mint, green tea and trifolium. The absorption bands of carbonate ions CO(3)(2-) was exhibited at 1446 cm(-1), and the phosphate ions PO(4)(3-) was assigned at 1105 and 1035 cm(-1). At high temperatures (600, 700 and 600°C) further absorption bands of the phosphate ions PO(4)(3-) was assigned at the frequencies 572, 617, 962, 1043 and 1110 cm(-1) and the vibrational absorption band of the carbonate ions CO(3)(2-) was assigned at 871, 1416 and 1461 cm(-1). X-ray diffraction and thermal analysis confirm the obtained results of FITR. Results showed that the main inorganic constituents of C. edulis and basil leaves are hydroxyapatite whereas the hydroxyapatite content in the other plant samples is less than that in case of C. edulis and basil plant leaves.

Method development and optimization for the determination of selenium in bean and soil samples using hydride generation electrothermal atomic absorption spectrometry.

The present investigation is the first part of an initiative to prepare a regional map of the natural abundance of selenium in various areas of Brazil, based on the analysis of bean and soil samples. Continuous-flow hydride generation electrothermal atomic absorption spectrometry (HG-ET AAS) with in situ trapping on an iridium-coated graphite tube has been chosen because of the high sensitivity and relative simplicity. The microwave-assisted acid digestion for bean and soil samples was tested for complete recovery of inorganic and organic selenium compounds (selenomethionine). The reduction of Se(VI) to Se(IV) was optimized in order to guarantee that there is no back-oxidation, which is of importance when digested samples are not analyzed immediately after the reduction step. The limits of detection and quantification of the method were 30 ng L(-1) Se and 101 ng L(-1) Se, respectively, corresponding to about 3 ng g(-1) and 10 ng g(-1), respectively, in the solid samples, considering a typical dilution factor of 100 for the digestion process. The results obtained for two certified food reference materials (CRM), soybean and rice, and for a soil and sediment CRM confirmed the validity of the investigated method. The selenium content found in a number of selected bean samples varied between 5.5±0.4 ng g(-1) and 1726±55 ng g(-1), and that in soil samples varied between 113±6.5 ng g(-1) and 1692±21 ng g(-1).