Energy Dispersive X-ray Microanalysis Research Articles

Spectroscopic investigation of the carbon nanotubes and polysiloxane coatings on titanium surface

Confocal Raman spectroscopy and DRS-FT-IR spectroscopy were used to study three types of coatings o pure titanium prepared by the electrophoretic deposition (EPD). The tests based on the comparison of the spectroscopic data for the multi-walled carbon nanotubes/polysiloxane (MWCNTs/PS) coating with the results obtained for those of pure MWCNTs and PS. The studies have shown that micro-Raman confocal spectroscopy applied to the coatings containing MWCNTs is a valuable tool that allows to determine the characteristics of MWCNTs which could be related to the functional properties of the coatings applied on metallic surfaces. Infrared spectroscopy studies of the MWCNTs/PS nanocomposite coating provided data on the interactions between its two components. The comparison of this information with the results obtained for the pure PS coating allowed to characterize the changes in the polymer structure caused by the presence of carbon nanotubes (CNTs). The coatings were also examined using scanning electron microscopy (SEM) and energy dispersive X-ray microanalysis (EDS).

ANALYSIS OF CHANGES IN THE PHASE AND STRUCTURAL STATE OF AN ALUMINUM ALLOY 1933 SURFACE LAYER, MELTED BY A PULSED ELECTRON BEAM

The structural and phase changes in the surface layer of an aluminum alloy 1933 caused by the action of a relativistic pulsed electron beam are studied. The structural and phase state of this layer is determined by the impact action of the electron beam and by the kinetics of crystallization from the melt under ultrafast cooling. The impact of a pulsed electron beam is accompanied by the formation of a developed surface relief and the appearance of microcracks on it. The structure of the modified layer is nonequilibrium. X-ray diffraction studies and the results of energy dispersive X-ray microanalysis made it possible to determine that magnesium oxide inclusions are present in the remelted layer. MgO inclusions are generally uniformly distributed in the remelted layer. The maximum size of MgO inclusions does not exceed 1 μm. The causes and mechanisms of the formation of magnesium oxide during the action of a pulsed electron beam are discussed.

Entrapment of Bradysia paupera (Diptera: Sciaridae) by Phaseolus vulgaris (Fabaceae) plant leaf

Flies of the genus Bradysia (Diptera, Sciaridae) are considered as major insect pests of greenhouse-grown horticultural crops. The ability of hooked trichomes of the French bean Phaseolus vulgaris to impale and entrap herbivorous insects thus resulting in insect reduced longevity, reproduction and larval mortality is well known. The present study investigates under laboratory conditions the ability of hooked trichomes of bean leaves to entrap fungus gnats Bradysia paupera, in order to estimate the reduction of their population. We characterized the entrapment mechanism of hooked trichomes towards B. paupera using cryo-scanning electron microscopy, and evaluated the silicon distribution in hooked trichomes with the energy dispersive X-ray microanalysis. We evaluated the trapping efficiency of hooked trichomes in fertilized and unfertilized bean plants towards B. paupera, in comparison with insects feeding on the plant leaf such as black bean aphid Aphis fabae and young stages of the southern green stinkbug Nezara viridula. For B. paupera, we recorded about 30% of entrapped insects in unfertilized plants. Considering the number of entrapped insects in relation to the leaf surface, the percentage of entrapped insect was higher in unfertilized than in fertilized plants having lower density of hooked trichomes. The presence of P. vulgaris plants in greenhouses could represent a useful method in integrated pest management to reduce Bradysia spp. population.

Pt Modified Heterogeneous Catalysts Combined with Ozonation for the Removal of Diclofenac from Aqueous Solutions and the Fate of by-Products

The degradation of the pharmaceutical compound diclofenac in an aqueous solution was studied with an advanced oxidation method, catalytic ozonation. Diclofenac was destroyed in a few minutes by ozonation but several long-lasting degradation by-products were formed. For this reason, the combination of heterogeneous catalysts and ozonation was applied to eliminate them completely. The kinetics of the diclofenac degradation and the formation of by-products were thoroughly investigated. Loading of Pt on the catalysts resulted in an improvement of the activity. The Mesoporous Molecular Sieves (MCM) were one of the promising catalysts for the degradation of organic pollutants. In this study, six heterogeneous catalysts were screened, primarily MCM-22-100 catalysts with different Pt concentrations loaded via the evaporation-impregnation (EIM) method, and they were applied on the degradation of diclofenac. It was found that the presence of Pt improved the degradation of diclofenac and gave lower concentrations of by-products. The 2 wt % Pt-H-MCM-22-100-EIM demonstrated the highest degradation rate compared to the proton form, 1% or 5 wt % Pt concentration, i.e., an optimum was found in between. Pt-H-Y-12-IE and Pt-γ-Al2O3 (UOP)-IMP catalysts were applied and compared with the MCM-22 structure. Upon use of both of these catalysts, an improvement in the degradation of diclofenac and by-products was observed, and the 2 wt % Pt-H-MCM-22-100-EIM illustrated the maximum activity. All important characterization methods were applied to understand the behavior of the catalysts (X-ray powder diffraction, transmission electron microscopy, nitrogen physisorption, scanning electron microscopy, energy dispersive X-ray micro-analyses, pyridine adsorption-desorption with FTIR spectroscopy, X-ray photoelectron spectroscopy). Finally, leaching of Pt and Al were analyzed by inductively coupled optical emission spectrometry.

Highly Efficient Gold Nano-Flower Optical Biosensor Doped in a Sol-Gel/PEG Matrix for the Determination of a Calcitonin Biomarker in Different Serum Samples.

We developed a novel, simple, sensitive, accurate, and precise method for the determination of calcitonin in different serum samples with medullar thyroid carcinoma. The designed flower-like thin film gold nanoparticles doped in a sol–gel/polyethylene glycol mold are used as an optical biosensor for the efficient determination of calcitonin. The sensor was characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray microanalysis, and Fourier-transform infrared spectroscopy. The efficiency of the considered bio-sensor is done using the quencher calcitonin of the emission band at 360 nm of biomarker obtained at λex = 333 nm in acetonitrile solvent. The sensing mechanism was based on fluorescence resonance energy transfer. The remarkable quenching of the fluorescence intensity at 360 nm of optical sensor by various concentrations of calcitonin was successfully used as an optical biosensor for the assessment of calcitonin for different serum samples of patients with medullar thyroid carcinoma. The calibration plot was prepared for the concentration range 0.01–1000 pg/mL of calcitonin with a correlation coefficient of 0.99 and a detection limit of 0.707 pg/mL. The suggested method augments the sensitivity of calcitonin as a useful biomarker for the early diagnosis of medullar thyroid carcinoma. This method is considered as a gateway for the construction of a new prototype for the follow-up of thyroid cancer in the spinal cord during and after treatment.

Breast-Specific Gamma Imaging with [99mTc]Tc-Sestamibi: An In Vivo Analysis for Early Identification of Breast Cancer Lesions Expressing Bone Biomarkers.

The main purpose of this pilot investigation was to evaluate the possible relationship among [99mTc]Tc-Sestamibi uptake, the presence of breast osteoblast-like cells, and the expression of molecules involved in bone metabolism, such as estrogen receptor, bone morphogenetic proteins-2, and PTX3. To this end, forty consecutive breast cancer patients who underwent both breast-specific gamma imaging with [99mTc]Tc-Sestamibi and breast bioptic procedure were retrospectively enrolled. From each diagnostic paraffin block collected in the study, histological diagnosis, immunohistochemical investigations, and energy dispersive X-ray microanalysis were performed. Our data highlight the possible use of breast-specific gamma imaging with [99mTc]Tc-Sestamibi for the early detection of breast cancer lesions expressing bone biomarkers in the presence of breast osteoblast-like cells. Specifically, we show a linear association among sestamibi uptake, the presence of breast osteoblast-like cells, and the expression of estrogen receptor, bone morphogenetics proteins-2, and PTX3. Notably, we also observed an increase of [99mTc]Tc-Sestamibi in breast cancer lesions with magnesium-substituted hydroxyapatite. In conclusion, in this pilot study we evaluated data from the nuclear medicine unit and anatomic pathology department on breast cancer osteotropism, identifying a new possible interpretation of Breast Specific Gamma Imaging with [99mTc]Tc-Sestamibi analysis.

Advanced methods for the analysis of Roman wall paintings: elemental and molecular detection by means of synchrotron FT-IR and SEM micro-imaging spectroscopy

The reconstruction of Roman decorative apparatus from delocalized fragments is an arduous challenge for the archaeologists. An archaeometric approach may integrate the archaeological analyses, based on the stylistic observations, improving the ability to merge adjacent fragments, especially in the absence of distinctive ornamental elements. In this work, the capacity of reflection FT-IR spectroscopy combined with chemometric tools to identify groups of fragments that have similar chemical composition of the pictorial layers is tested. Synchrotron radiation-based Fourier transform infrared (SR-FTIR) microspectroscopy coupled with scanning electron microscopy (SEM) and energy-dispersive X-ray micro-analysis (EDX) performed on cross section were used to enhance the performance of conventional FT-IR technique and to localize micrometric-size compounds. The chemometric approach proposed in this work turns out to be a powerful way to discriminate pictorial layers with similar chemical composition, by the identification of different compounds. The use of SR source has permitted to improve the lateral resolution and to discriminate neighboring micro-compounds, such as quartz and cuprorivaite in Egyptian blue pigments.

Toxicity, Physiological, and Ultrastructural Effects of Arsenic and Cadmium on the Extremophilic Microalga Chlamydomonas acidophila.

The cytotoxicity of cadmium (Cd), arsenate (As(V)), and arsenite (As(III)) on a strain of Chlamydomonas acidophila, isolated from the Rio Tinto, an acidic environment containing high metal(l)oid concentrations, was analyzed. We used a broad array of methods to produce complementary information: cell viability and reactive oxygen species (ROS) generation measures, ultrastructural observations, transmission electron microscopy energy dispersive x-ray microanalysis (TEM–XEDS), and gene expression. This acidophilic microorganism was affected differently by the tested metal/metalloid: It showed high resistance to arsenic while Cd was the most toxic heavy metal, showing an LC50 = 1.94 µM. Arsenite was almost four-fold more toxic (LC50= 10.91 mM) than arsenate (LC50 = 41.63 mM). Assessment of ROS generation indicated that both arsenic oxidation states generate superoxide anions. Ultrastructural analysis of exposed cells revealed that stigma, chloroplast, nucleus, and mitochondria were the main toxicity targets. Intense vacuolization and accumulation of energy reserves (starch deposits and lipid droplets) were observed after treatments. Electron-dense intracellular nanoparticle-like formation appeared in two cellular locations: inside cytoplasmic vacuoles and entrapped into the capsule, around each cell. The chemical nature (Cd or As) of these intracellular deposits was confirmed by TEM–XEDS. Additionally, they also contained an unexpected high content in phosphorous, which might support an essential role of poly-phosphates in metal resistance.

Supporting PtRh alloy nanoparticle catalysts by electrodeposition on carbon paper for the ethanol electrooxidation in acidic medium

Pt80Rh20 and Pt60Rh40 alloy catalysts were electrodeposited at constant current density from different electrolytic baths on commercial carbon paper in order to be tested for the ethanol oxidation reaction (EOR) and as anodes in a direct ethanol fuel cell (DEFC). Pt and Rh anodes prepared in the same form were also examined for comparison. As measured by energy-dispersive X-ray microanalyses, the electrodeposited Pt:Rh atomic ratios were the same as those of the precursors in the bath. X-ray diffraction showed the PtRh alloy formation with mean particle sizes of 8.3 and 7.0 nm for Pt80Rh20 and Pt60Rh40, respectively, and a Pt lattice contraction caused by the Rh addition. The X-ray photoelectron spectroscopy analyses suggested a Pt lattice strain due to Rh alloying because the Pt4f binding energies were shifted to higher values with respect to that of pure Pt. The onset potentials of the alloy oxidation, CO stripping and ethanol oxidation in the cyclic and linear sweep voltammograms indicated that Pt60Rh40 was the most active for the CO and the ethanol electrooxidation. The apparent activation energies for the EOR on that alloy were also the lowest one, in agreement with its highest activity. These results were explained by the bifunctional mechanism, assuming that Rh contributed with hydroxylated species to favor the removal of the CO-type adsorbed species on Pt sites, and by the effect of Rh on the Pt electronic structure, the lattice strain being dominating over the charge transfer between Rh and Pt. Tests carried out in single DEFCs showed the feasibility of using the Pt60Rh40 electrodeposited electrodes on carbon as the anode in a real fuel cell environment.

Study of the influence of dopant precursor on the growth and properties of Li-doped ZnO

Lithium-doped ZnO structures with sizes in the micro- and nano-scale and different morphologies were obtained by vapor–solid growth method. Two different precursors, lithium oxide and lithium carbonate, were used as the lithium source in order to study the influence on the morphology and optical properties of the obtained structures. Scanning electron microscopy, cathodoluminescence, photoluminescence, X-ray diffraction, energy dispersive X-ray microanalysis and Raman spectroscopy were used to characterize their structure, morphology, composition and optical properties. Depending on the lithium content present, changes in the crystalline quality and the luminescent intensity of the samples were observed. Optical resonant cavity behavior was also observed in some of the nano-structures.

Structural and electrochemical characterization of lawsone-dependent production of tellurium-metal nanoprecipitates by photosynthetic cells of Rhodobacter capsulatus

Cells of the facultative photosynthetic bacterium Rhodobacter capsulatus exploit the simultaneous presence in the cultural medium of the toxic oxyanion tellurite (TeO32−) and the redox mediator lawsone (2-hydroxy-1,4-naphthoquinone) by reducing tellurite to metal Te0 nanoprecipitates (TeNPs) outside the cells. Here we have studied the mechanism by which lawsone interacts with metabolically active cells and analysed both structure and composition of the TeNPs collected from the growth medium of phototrophycally grown R. capsulatus. High Resolution Transmission Electron Microscopy (HR-TEM) images and Energy-Dispersive X-ray (EDX) microanalysis of TeNPs showed a central core of polycrystalline tellurium interspersed in an organic matrix with a predominant protein-based composition. The main proteins from Te0 nanostructures were identified by Liquid Chromatography tandem-Mass Spectrometry and were all correlated with the cell outer membrane composition. The interaction of reduced lawsone with tellurite and with the bacterial cells was probed by Cyclic Voltammetry and Scanning ElectroChemical Microscopy (SECM). We concluded that lawsone is required for the reduction of tellurite to metal Te0 in a reaction mechanism dependent on reducing equivalents deriving from the cell photosynthetic metabolism. SECM experiments demonstrate that lawsone, by diffusing inside the bacterial cells, is effectively available at the membrane site of the photosynthetic electron transport chain.

New Synthesis of Solid-Solution Lead Hydroxyapatite (PbHAP) by Ceramic and Semi-Ceramic Methods

The synthesis of solid solutions lead hydroxyapatite, Pb10(PO4)6*y(OH)2, were successfully synthesized by solid-state reaction (ceramic method) (y= 0.95; 0.96; 0.97; 0.98; 0.99 and 1.00) and precipitation (semi ceramic method) (y= 0.97; 0.98; 0.99 and 1.00) methods at 800 and#186;C for 50 hours. The X-ray powder diffraction (DRON-3m diffractometer), electron microscopy scanning (SEM) and energy dispersive X-ray micro-analysis which characterized all samples. It has been established that Pb10(PO4)5.82(OH)2 and Pb10(PO4)5.88(OH)2 are the best synthesis for lead hydroxyapatite in the solid-state reaction method, and Pb10(PO4)5.88(OH)2 is the precipitation method.

New Synthesis of Solid-Solution Lead Hydroxyapatite (PbHAP) by Ceramic and Semi-Ceramic Methods

The synthesis of solid solutions lead hydroxyapatite, Pb10(PO4)6*y(OH)2, were successfully synthesized by solid-state reaction (ceramic method) (y= 0.95; 0.96; 0.97; 0.98; 0.99 and 1.00) and precipitation (semi ceramic method) (y= 0.97; 0.98; 0.99 and 1.00) methods at 800 and#186;C for 50 hours. The X-ray powder diffraction (DRON-3m diffractometer), electron microscopy scanning (SEM) and energy dispersive X-ray micro-analysis which characterized all samples. It has been established that Pb10(PO4)5.82(OH)2 and Pb10(PO4)5.88(OH)2 are the best synthesis for lead hydroxyapatite in the solid-state reaction method, and Pb10(PO4)5.88(OH)2 is the precipitation method.

Compositional and microhardness findings in tooth affected by X-linked hypophosphatemic rickets.

BackgroundThis study aimed to evaluate the X-linked hypophosphatemic rickets (XLHR)-related compositional and microhardness tooth aspects. Material and MethodsOne affected and one non-affected teeth by XLHR were sectioned transversely, and each section was separated for Micro-Raman spectroscopy, Knoop microhardness and scanning electron microscopy with energy dispersive x-ray microanalysis (SEM-EDS). The outcomes of these analyses were assessed. ResultsOutcomes of Raman analysis of inorganic/organic components (~958/~1250+~1450 cm−1) and carbonate/phosphate (~1070/~958 cm−1) ratios showed areas of altered enamel and dentin (interglobular dentin, calcospherites, and mantle dentin) with an increase of inorganic content in the rickets tooth. Microhardness reduction was observed in the affected tooth, with a more evident drop in regions of mantle dentin, interglobular dentin, and calcospherites. SEM-EDS analysis showed demonstrated the absence of calcium and phosphorus in interglobular spaces. ConclusionsIn conclusion, compositional and structural deficiencies were observed in deciduous tooth affected by XLHR. Also, it was observed the absence of hydroxyapatite in the interglobular dentin by using Raman spectroscopy analysis. Key words:Dentin, dentin permeability, X-linked hypophosphatemic rickets, tooth, tooth calcification, Raman spectroscopy.

Ultrasonically nanostructured electric-spark deposited Ti surface layer on Ti6Al4V alloy: enhanced hardness and corrosion resistance

A complex approach for the production of corrosion resistant nanostructured surface layer on the Ti6Al4V alloy is reported in this article. Surface modification was conducted using sequential application of electric discharge surface alloying (EDSA) with α-titanium and ultrasonic impact treatment (UIT) induced the nanostructuring of the EDSA-formed Ti-layer. X-ray diffraction and TEM analysis show that the applied modifications form the outmost surface layer of ~20 μm thick comprised the nanoscale grain structure with a grain size of 10-30 nm. Additionally, the UIT-induced mechanochemical oxidation of the modified surface was observed by SEM with energy dispersive X-ray microanalysis. The produced nanostructured α-titanium surface layer shows enhanced microhardness and better corrosion behaviour in saline solution than those of the original and UIT-processed Ti6Al4V alloys. Thus, the complex treatment applied can be recommended for the surface finishing of the products made of multi-phase titanium alloys, such as biomedical implants.

Hybrid Inorganic-Organic Materials Based on Shungite and Silver Nanoparticles

The physicochemical properties of artificial hybrid inorganic-organic material based on highly dispersed porous shungite and silver nanoparticles are investigated via energy dispersive X-ray microanalysis and surface activated spectrometry with laser desorption/ionization. Silver is found to be firmly secured on the shungite surface, forming clusters with shungite carbon. The hybrid material is well wetted by water and forms stable nanodispersions in water.

An organic-inorganic hybrid nanomaterial composed of a Dowson-type (NH4)6P2Mo18O62 heteropolyanion and a metal-organic framework: synthesis, characterization, and application as an effective adsorbent for the removal of organic dyes.

In this work, an inorganic–organic hybrid nanomaterial, P2Mo18/MIL-101(Cr), based on Wells–Dawson-type (NH4)6P2Mo18O62 polyoxometalate (abbreviated as P2Mo18) and the MIL-101(Cr) metal–organic framework was fabricated by the reaction of (NH4)6P2Mo18O62, Cr(NO3)3·9H2O and terephthalic acid under hydrothermal conditions. The as-prepared recyclable nanohybrid was fully characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) equipped with energy dispersive X-ray microanalysis (EDX), field emission scanning electron microscopy (FE-SEM), Raman spectroscopy and Brunauer–Emmett–Teller (BET) specific surface area studies. All the analyses confirmed the successful insertion of P2Mo18O626− heteropolyanion within the cavities of MIL-101(Cr). The encapsulated MIL-101(Cr) showed a considerable decrease in both pore volume and surface area compared with MIL-101(Cr) due to incorporation of the very large Dowson-type polyoxometalate into the three-dimensional porous MIL-101(Cr). The nanohybrid had a specific surface area of 800.42 m2 g−1. The adsorption efficiency of this nanohybrid for removal of methylene blue (MB), rhodamine B (RhB), and methyl orange (MO) from aqueous solutions was evaluated. Surprisingly, the composite not only presented a high adsorption capacity of 312.5 mg g−1 for MB, but also has the ability to rapidly remove 100% MB from a dye solution of 50 mg L−1 within 3 min. These results confirmed that this adsorbent is applicable in a wide pH range of 2–10. The nanohybrid showed rapid and selective adsorption for cationic MB and RhB dyes from MB/MO, MB/RhB, MO/RhB and MB/MO/RhB mixed dye solutions. The equilibrium adsorption data were better fitted by the Langmuir isotherm. Kinetics data indicate that the adsorption of the dye follows a pseudo-second order kinetics model. Also, this material could be effortlessly separated and recycled without any structural modification. Accordingly, it is an efficient adsorbent for removing cationic dyes.

Thermal Stability of Structure and Properties of Gradient and Gradient-Layered Coatings of the Ti–Al–Si–Cu–N System

Using the methods of dark-field electron microscopy analysis, energy-dispersive X-ray microanalysis, hardness measurements and scratch testing, the variations of elemental composition, structure and mechanical properties of gradient and gradient-layered coatings of the Ti–Al–Si–Cu–N system are investigated during annealing in vacuum at the temperatures within the range 973–1373 K. It is found out that at the annealing temperatures up to 1173 K such structural changes as equalization of the nitride-phase lattice parameter throughout the coating thickness and decreased lattice bending are due to the diffusion-induced redistribution followed by a drop in the concentration of the nitride-doping elements and precipitation of the nanosized copper crystals. For the annealing temperature 1373 K, a several-fold (compared to the state after deposition) decrease in the nitride-phase crystal lattice bending and a change in the concentration of the elements of a few tens of percent are revealed, as well as the formation of heterophase nanocrystalline structure during their localization at the interfaces. A similarity of the defect microstructure in the crystals of both coatings after annealing at 1373 K is determined. The influence of the structural-phase transformations on the variations in the hardness and adhesion strength values of the coatings is discussed.

Effect of nano-TiO2 content on the flexural strength and compressive strength of dry-Mixing CDG-Slag based geopolymer paste

In this paper, the effects of nano-titanium dioxide (TiO2) content on the 28-day flexural strength and 28-day compressive strength of Completely decomposed granite (CDG) and slag based geopolymer paste was investigated, using the dry-mixing method. The calcium hydroxide, sodium carbonate and solid sodium silicate were used as the alkali activator. The results show that with the increase of nano-titanium dioxide content increasing from 0 to 2.0%, the compressive strength and flexural strength gradually increase. In addition, the surface of geopolymer paste gradually became smooth. What’s more, the geopolymer paste microstructure was characterized by using Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray (EDX) Microanalysis, details of the research process and analysis are presented throughout the paper.

Phosphorus speciation in sediments from the Baltic Sea, evaluated by a multi-method approach

Phosphorus (P) is a crucial element for living organisms at both land and sea, but simultaneously, it can cause environmental problems especially in marine ecosystems. The pathway of P from soils through riverine and coastal systems to sea sediments has not been clarified to date. Thus, the main aim of this study was to characterize P species in sediments along a gradient from the coast of Northern Germany to the Baltic Proper. Six sediment samples along a transect from river outlets into the Baltic Sea in northeastern Germany to the deep basins at the Baltic Proper were analyzed. Four complementary methods were applied to explore the different sedimentary P compounds: (i) the sequential P fractionation to extract P from sediment pools of different solubility; (ii) P K-edge X-ray absorption near edge structure (XANES) spectroscopy as an element-specific method for speciation analyses of complex environmental samples; (iii) 31P nuclear magnetic resonance (31P NMR) spectroscopy as a capable technique distinguishing especially different organic P compounds based on their characteristic resonance frequencies and (iv) scanning electron microscopy (SEM) combined with energy-dispersive X-ray microanalyses (EDX) to identify certain solid particles and their elemental composition. Sequential P fractionation revealed a decrease in labile P pools (resin-P; NaHCO3-P) along with an increase in more stable P fractions (H2SO4-P; residual-P) from near-coastal sediments towards the Baltic Proper with increasing water depths of sediment deposits. In comparison, XANES analysis indicated a decline of Fe-associated P compounds in favor of Ca-bound P with increasing distance of sediments from the coastline into the Baltic Sea. Results of 31P NMR spectroscopy showed that the variety of different mono- and diester P compounds decreased with increasing distance from the coast and that high proportions of orthophosphate (ortho-P) were present especially in greater water depths. The SEM-EDX analysis supported most of these results by retriving Fe phosphate particles especially in the sediments near the coast. The integration of several P-specific methods enabled improved insights into P speciation. A trend towards more stable Ca-P compounds towards the Gotland basin was found with sequential fractionation and P-XANES. In the future, different types of sediments will be analyzed with respect to their interactions with adjacent soils to find out a common principle of P-transformations and derive approaches for capturing P before entering susceptible marine systems.