Amount Of Residual Water Research Articles

Wpływ napięcia międzyfazowego między ropą a wodą na stabilność emulsji ropnych

"The stability of crude oil emulsions sourced from wells in two distinct fields distinguished by varying physical-chemical properties was analysed. The oil taken from the wells of Muradkhanli and Balakhani fields of State Oil Company of the Azerbaijan Republic (SOCAR) has been used as the research object. Demulsification of both oils, whose composition differs in the amount of high molecular compounds, has been investigated through the static settling method for 2, 4, 6, 8, 10 and 12 hours, and the amount of residual water in the oil has been recorded. In the same time interval, the oils have been tested by adding n-hexane and phenol to them, respectively. During the experiments, it was discovered that after the addition of n-hexane, which is a saturated hydrocarbon, the surface tension force increased in both oil samples and caused the formation of water in the form of a dispersed phase in the oil, which resulted in an increase in stability. In particular, as the concentration of n-hexane in oil increased, oil emulsions became aggregative and kinetically stable. The experiments conducted involving the addition of phenol to oils revealed that an increase in the volume of phenol in the oil led to a decrease in the surface tension force at the oil-water boundary, thereby accelerating the demulsification process. Subsequently, the research extended to investigating the emulsion stability of the oil samples by adding phenol and n-hexane in varying proportions. It was observed that an increase in the phenol ratio expedited the demulsification process, whereas a higher hexane ratio weakened it. Throughout the experimental tests, fluctuations in demulsification rates were noted upon the addition of organic substances to the oil samples. Furthermore, an increase in the concentration of high molecular compounds in the oil composition resulted in elevated surface tension, posing challenges in separating the water phase from the oil. The demulsification ability of organic substances added to crude oil samples, compositions A, B and C (25% n-hexane and 75% phenol (conditional name A), 50% n-hexane and 50% phenol (conditional name B), 75% n-hexane and 25% phenol (conditional name C)) prepared on the basis of these organic substances was examined depending on the surface tension.

Impact of post-freeze annealing on shrinkage of sucrose and trehalose lyophilisates

Freeze-drying of pharmaceuticals produces lyophilisates with properties that depend on both the formulation and the process. Characterisation of the lyophilisate in terms of appearance is necessary not only to produce a visually appealing product, but also to gain insight into the freeze-drying process. The present study investigates the impact of post-freeze annealing on the volume of lyophilisates. For this purpose, sucrose and trehalose solutions were freeze-dried with different annealing conditions and the resulting lyophilisates were analysed with a 3D structured light scanner. The external structure of the lyophilisates was found to be dependent on the bulk materials as well as the choice of vials, while the volume was influenced by the annealing time and temperature. Additionally, differential scanning calorimetry was used to determine glass transition temperatures of frozen samples. As a novelty, the volumes of the lyophilisates and their corresponding glass transition temperatures were compared. This resulted in a correlation supporting the theory that the shrinkage of lyophilisates depends on the amount of residual water in the freeze-concentrated amorphous phase before drying. Understanding the volume change of lyophilisates, in combination with material properties such as glass transition temperature, forms the basis for relating physicochemical properties to process parameters in lyophilisation.

EVALUATION FOR BALLAST TANK DRAINAGE BY HYDRAULICS EXPERIMENT

The quality of the ballast water drainage system during the cargo handling process of ships is an important issue for those involved in marine transportation such as cargo owners and shipping companies as it is significantly related to their revenue shipping. An excess charge is incurred if moored beyond the scheduled time due to the loading time, and the deadweight tonnage superfluity residual water reduces the deadweight tonnage. To minimize the loss of their transportation, this paper addressed two problems: shortening the ballast drainage time and minimizing the amount of residual water in the ballast tank. The objective of this study was to construct an optimal ballast drainage system to solve these problems. In this paper, hydraulic experiments modelling the drainage of the ballast tank were conducted to evaluate the drainage system's design policy and reveal the optimum design condition of a ballast tank.

Separation of bio-based acetoin from model fermentation broths by salting-out with high-solubility inorganic salts

The downstream separation of acetoin from microbial fermentation broths is a complex process, which has become the bottleneck of large-scale production. In this study, salting-out was proved to be an effective separation method. Three high-solubility potassium salts, K4P2O7, K2CO3 and K2HPO4, were used to recover acetoin from three different concentrations of model acetoin fermentation broth at 298.15 K. Under the optimized conditions, the recovery of acetoin in the model aqueous solution could reach 99.7 %, which was obviously higher than other separation methods. The residual amount of water in the organic phase was 7.67 wt%, while only 0.026 wt% acetoin remained in the aqueous phase. The salting-out ability of the three high-solubility inorganic salts to acetoin model fermentation broth showed the following sequence: K4P2O7 > K2HPO4 > K2CO3. In addition, the content of acetoin in the aqueous phase and the residual amount of water in the organic phase could be calculated by the total linear regression equation in the range of 5 wt% to 10 wt% acetoin concentration. Because inorganic salts have strong stability, low cost and non-toxic, this process shows a good prospect of industrial application.

Characterization of Sodium Alginate Hydrogels Reinforced with Nanoparticles of Hydroxyapatite for Biomedical Applications.

In recent years, researchers working in biomedical science and technology have investigated alternatives for enhancing the mechanical properties of biomedical materials. In this work, sodium alginate (SA) hydrogel-reinforced nanoparticles (NPs) of hydroxyapatite (HA) were prepared to enhance the mechanical properties of this polymer. Compression tests showed an increase of 354.54% in ultimate compressive strength (UCS), and 154.36% in Young’s modulus with the addition of these NPs compared with pure SA. Thermogravimetric analysis (TGA) revealed that the amount of residual water is not negligible and covered a range from 20 to 35 wt%, and the decomposition degree of the alginate depends on the hydroxyapatite content, possibly due to the displacement of sodium ions by the hydroxyapatite and not by calcium chloride. Further, there is an important effect possibly due to the existence of an interaction of hydrogen bonds between the hydroxyl of the alginate and the oxygen atoms of the hydroxyapatite, so signals appear upfield in nuclear magnetic resonance (NMR) data. An increase in the accumulation of HA particles was observed with the use of X-ray microtomography, in which the quantified volume of particles per reconstructed volume corresponded accordingly to the increase in the mechanical properties of the hydrogel.

A Global Model for Predicting Vacuum Drying of Used Nuclear Fuel Assemblies

A global model is proposed to simulate the drying process of used nuclear fuel assemblies under vacuum drying conditions. The transient model consists of a coupled mass and energy conservation equation with appropriate source and sink terms. The classic Hertz-Knudsen expression is employed to resolve the evaporation rate and the associated water mass depletion in the system. Both latent heat of vaporization and residual decay heat are considered as sink and source in the energy conservation, respectively. The model is employed to simulate vacuum drying of spent nuclear fuel rod storage systems. Multistage stepwise vacuuming of the system is emulated, and several parametric studies are conducted to identify their role in the drying process. The predicted temporal profiles show that the proposed model is able to capture qualitative trends of the water removal rate, hence the dryness level of the system. The model prediction is also compared against experiments where the amount of residual water after a standard vacuum drying procedure is quantified. The predictions are found to compare favorably with the experimental measurements.

Real-Time In situ XRD Study of Simvastatin Crystallization in Levitated Droplets

Simvastatin (SV) is an important active pharmaceutical ingredient (API) for treatment of hyperlipidemias, which is known to exist in different crystalline and amorphous phases. It is, therefore, an interesting model to investigate how the outcome of evaporative crystallization in the contactless environment of an acoustically levitated droplet may be influenced by key experimental conditions, such as temperature, solvent properties (e.g., polarity and hygroscopicity), and dynamics of the evaporation process. Here, we describe a real-time and in situ study of simvastatin evaporative crystallization from droplets of three solvents that differ in volatility, polarity, and protic character (acetone, ethanol, and ethyl acetate). The droplet monitorization relied on synchrotron X-ray diffraction (XRD), Raman spectroscopy, imaging, and thermographic analysis. A pronounced solvent-dependent behavior was observed. In ethanol, a simvastatin amorphous gel-like material was produced, which showed no tendency for crystallization over time; in ethyl acetate, a glassy material was formed, which crystallized on storage over a two-week period to yield simvastatin form I; and in acetone, form I crystallized upon solvent evaporation without any evident presence of a stable amorphous intermediate. The XRD and Raman results further suggested that the persistent amorphous phase obtained from ethanol and the amorphous precrystallization intermediate formed in ethyl acetate were similar. Thermographic analysis indicated that the evaporation process was accompanied by a considerable temperature decrease of the droplet surface, whose magnitude and rate correlated with the solvent volatility (acetone > ethyl acetate > ethanol). The combined thermographic and XRD results also suggested that, as the cooling effect increased, so did the amount of residual water (most likely captured from the atmosphere) remaining in the droplet after the organic solvent was lost. Finally, the interpretation of the water fingerprint in the XRD time profiles was aided by molecular dynamics simulations, which also provided insights into the possible role of H2O as an antisolvent that facilitates simvastatin crystallization.

WELL SCREEN FOR THE TECHNOLOGY OF WATER- CUT OIL DOWNHOLE SEPARATION

Background According to a number of studies, the efficiency of the preliminary water discharge units in terms of the quality of the discharged water and the amount of residual water in oil depends on the degree of destruction. With an increase in the latter, the efficiency of the pre-dumping installations increases significantly. In oil-gathering reservoirs, due to the relatively low flow rates, emulsification of liquids practically does not occur and, moreover, conditions are created for the deposition of large water droplets along the cross-section of the pipeline and the formation of a continuous underlying layer of water, which can be captured by ground filters. The most intensive emulsification of formation fluids occurs in the working bodies of electric centrifugal pumps in production wells. The emulsions formed in these pumps have the greatest stability and interface. Aims and Objectives To prepare liquids for stratification in pre-discharge units, it is most expedient to install filters in separator wells before electric centrifugal pumps. The authors consider that the disadvantage of these installations is the insufficient quality of water treatment, since water is not filtered from solid suspended particles and oil globules. To solve this problem, it is proposed to install a volumetric filtration filter made from a package of brush disks and located on a tubing string in a downhole water discharge unit. Results The results of bench tests of the structure of the downhole volumetric filtration filter for the downhole separation technology are presented, the layouts of the main submersible equipment are shown. It has been substantiated that the use of this filter will allow: o to increase the productivity of wells due to the efficiency of gravitational stratification of water-oil liquid on the developed surface of the filter brush discs; o reduce the cost of the filter cleaning operation in comparison with known filters; o to increase the degree of purification of the product (water) from impurities; o prevent erosional destruction of the inner surface of the tubing string.

High conductive hybrid polymer CsH5(PO4)2-Butvar compounds

Hybrid polymer compounds (1–х)CsH5(PO4)2-хButvar (х=0– 0.3), synthesized with different solvents (ethanol and isopropanol) were first synthesized and investigated. Fundamental possibility of creating new highly conductive thin polymer electrolytes based on CsH5(PO4)2 was shown. An optimal synthesis method was determined. The crystal structure of CsH5(PO4)2 (P21/c) remains unchanged in the polymer system. The thickness of the electrolyte is no more than 50-100 μm. Proton conductivity increases by 2 orders of magnitude and depends on the composition. The highest conductivity was 10-1 S/cm at 135 °C. Changes in conductivity are caused by dispersion of the salt, as well as by the presence of insignificant amounts of residual water under the synthesis conditions.

Comparison of pulmonary circulation hemodynamics and respiratory mechanics induced by drowning with equal volume of freshwater and seawater in sheep: a randomized controlled study

To compare the effects of freshwater and seawater drowning on sheep's pulmonary circulation hemodynamics and respiratory mechanics. According to the random number table method, healthy crossbred sheep were divided into freshwater drowning group (n = 12) and seawater drowning group (n = 12). 30 mL/kg of freshwater or seawater was infused respectively through trachea for approximately 5 minutes. Before the drowning, immediately after drowning, and 30, 60, 120 minutes after drowning, the systemic circulation hemodynamic parameters [heart rate (HR), mean arterial pressure (MAP), cardiac output (CO)] were monitored by pulse indicator continuous cardiac output (PiCCO); the respiratory parameters were obtained through the ventilator, including tidal volume (VT), lung compliance (Cdyn), oxygenation index (PaO2/FiO2), peak airway pressure (Ppeak)]; PiCCO and the right heart floating catheter (Swan-Ganz catheter) was used to measure pulmonary hemodynamic parameters [pulmonary systolic pressure (PAS), pulmonary diastolic pressure (PAD), pulmonary artery wedge pressure (PAWP), and extravascular lung water (EVLW)]. The animals were sacrificed at the end of the experiment, and the amount of residual water in the respiratory tract was measured; the pathological changes in the lung tissue were observed by hematoxylin-eosin (HE) staining. (1) Systemic circulation hemodynamics: compared with the values before drowning, HR, MAP, and CO at the time of immediately after drowning in both freshwater and seawater were significantly increased and peaked. In addition, all indicators in the freshwater drowning group were significantly higher than those in the seawater drowning group [HR (bpm): 170.75±1.87 vs. 168.67±2.27, MAP (mmHg, 1 mmHg = 0.133 kPa): 172.92±1.62 vs. 159.42±3.18, CO (L/min): 13.27±0.71 vs. 10.33±0.73, all P < 0.05]. (2) Respiratory parameters: compared with values before drowning, PaO2/FiO2, VT, and Cdyn decreased immediately in both freshwater and seawater drowning groups, Ppeak was significantly increased; in addition, the values in the seawater drowning group were decreased or increased more significantly than freshwater drowning group [PaO2/FiO2 (mmHg): 37.83±1.99 vs. 60.42±5.23, VT (mL): 86.25±7.66 vs. 278.75±9.67, Cdyn (mL/cmH2O): 8.86±0.33 vs. 23.02±0.69, Ppeak (cmH2O, 1 cmH2O = 0.098 kPa): 42.17±2.69 vs. 17.67±1.15, all P < 0.01]. In addition, PaO2/FiO2 in the freshwater drowning group was gradually increased over time, while the seawater group continued to decline. (3) Pulmonary circulation hemodynamic parameters: PAS, PAD, PAWP at the time of immediately after drowning in both freshwater and seawater groups were significantly higher than before drowning; in addition, the freshwater drowning group was significantly higher than the seawater drowning group [PAS (mmHg): 34.58±2.87 vs. 26.75±1.66, PAD (mmHg): 27.25±1.22 vs. 16.75±0.87, PAWP (mmHg): 27.83±1.85 vs. 11.75±1.82, all P < 0.01]. Thereafter, PAS and PAD in the freshwater drowning group gradually decreased, while the parameters in the seawater drown group continued to increase. PAWP gradually decreased after freshwater or seawater drowning, and recovered to pre-drowning levels 120 minutes after drowning and 30 minutes after drowning, respectively. EVLW continued to increase after freshwater drowning, reaching a peak at 30 minutes, and then decreased, until 120 minutes after drowning was still significantly higher than that before drowning (mL/kg: 10.73±1.27 vs. 7.67±0.69, P < 0.01); EVLW could not be measured. (4) Residual water in the respiratory tract: residual water in the freshwater drowning group was significantly less than that in the seawater drowning group (mL: 164.33±25.21 vs. 557.33±45.23, P < 0.01). (5) HE staining: partial alveolar atrophied in the freshwater drowning group, some alveolar spaces were broken, alveolar spaces and alveolar cavity showed a little powdery substance deposition; it was noted that alveolar expanded in the seawater drowning group, alveolar spaces were broken and bleeding and edema were obvious in the interstitial space. The effect of seawater drowning on the respiratory mechanics and pulmonary circulation of animals is more obvious than that of freshwater drowned animals, and the amount of residual water in the respiratory tract is also significantly more than that of freshwater drowned animals.

Bioprotection Can Be Tuned with a Proper Protein/Saccharide Ratio: The Case of Solid Amorphous Matrices.

Saccharides, and in particular trehalose, are well known for their high efficiency in protecting biostructures against adverse environmental conditions. The protein dynamics is known to be highly inhibited in a low-water trehalose host medium, the inhibition being markedly dependent on the amount of residual water. Besides hydration, the protein/sugar ratio is expected to affect the properties of saccharide amorphous matrices. In this work, we report an infrared spectroscopy study in dry amorphous matrices of various sugars (the disaccharides trehalose, maltose, sucrose, and lactose, and the trisaccharide raffinose) containing myoglobin, at different protein/sugar ratios. We analyze the stretching band of the bound CO molecule and the water association band. Such bands have already been successfully exploited for the simultaneous study of thermal evolution of a matrix and embedded protein. The results show a high dependence of protein and matrix signals on the protein/sugar ratio, the system behavior evolving from situations where (i) the protein slaves the matrix to (ii) protein ↔ matrix coupling/uncoupling, then to (iii) the matrix slaving the protein, with increasing sugar concentration. This supports a mutual protein ↔ matrix structural and dynamic influence in low hydrated systems, indicating that the protein/solvent master and slave paradigm does not strictly hold, but the mutual relationship depends on the relative concentrations. Furthermore, for each sugar, an optimal protein/sugar concentration ratio can be identified, which maximizes the protein preservation; under such a condition, the water content is minimal.

An experimental study on oven-drying methods for laboratory determination of water content of a calcium-rich bentonite

Studies on the dehydration of montmorillonites imply that the standard oven-drying method (drying at 110 ± 5°C) may underestimate the water content of bentonites. This study quantifies, identifies, explains, and removes the residual water in a calcium-rich bentonite dried using the standard oven-drying method. A thermogravimetric-differential scanning calorimetry (TG-DSC) test was performed to determine the true water content. According to this test, the effect of the drying time and temperature on the amount of residual water in the bentonite was examined, including the oven-drying and vacuum-drying methods. To identify and explain the residual water, specific surface area (SSA) derived from the nitrogen adsorption isotherm and dehydration reaction characterised by TG-DSC curves of samples with a residual water content of 0–13.38% were obtained. The experimental results demonstrate that the standard oven-drying method underestimates the water content of calcium-rich bentonites by 2.1–3.1%. The 2.1–3.1% of residual water includes both interlayer water and adsorbed water on the external surface. The 2.1–3.1% of residual water is the water forming the inner shell around Ca2+ cations in the interlayer and on the external surface of montmorillonite particles. It is impractical to distinguish between the adsorbed water and interlayer water only based on the dehydration reaction characterised by TG-DSC curves. Drying profiles of 12h of drying at 200°C in an oven and 1h of drying at 150–200°C under vacuum are sufficient for removing the adsorbed and interlayer waters from the bentonite.

Concentration Distribution of Droplets in a Liquid‐Liquid Hydrocyclone and its Application

AbstractThe concentration distribution of droplets in liquid‐liquid hydrocyclones was studied using a phase Doppler particle analyzer. The effect of cone angle and inlet flow flux on the concentration distribution of droplets was determined. The cone angle of the hydrocyclone obviously influenced the maximum droplet concentration, especially that in the cone section. The hydrocyclone with a cone angle of 6° presented the best separation result. A higher inlet flow rate enhanced the separation of droplets from the water. The concentration profiles at five different axial heights presented a parabola law pattern in the radial direction. The optimized hydrocyclone was applied for the dewatering of vinyl chloride monomer (VCM). The amount of residual water could be greatly reduced.

Direct Reduction of Alkyl Monohalides at Silver in Dimethylformamide: Effects of Position and Identity of the Halogen

AbstractElectrochemical reduction of primary (1‐halodecane), secondary (2‐halohexane and cyclohexyl halide), and tertiary halides (tert‐butyl halide) at a silver cathode in dimethylformamide (DMF) containing 0.050 M tetramethylammonium perchlorate (TMAP) was investigated with the aid of cyclic voltammetry and controlled‐potential (bulk) electrolysis for iodides, bromides, and chlorides. Selected reductions were probed in dried DMF–TMAP and DMF containing tetra‐n‐hexylammonium perchlorate (THAP). Cyclic voltammograms reveal that the number of cathodic peaks and their potentials are highly dependent on the identity and position of the halogen as well as the composition of the solvent–electrolyte. Intermediates arising from bulk electrolysis of these halides at silver undergo both radical and carbanion reactions. Electrolysis products depend on the identity and position of the halogen, amount of residual water, and size of the electrolyte cation in the solvent–electrolyte. Theoretical calculations of molecular dipole moments and polarizabilities were performed and compared to experimental observations.

Survival of influenza A virus on contaminated student clothing.

The role of contaminated clothing in the transmission of influenza A virus during an epidemic period was investigated by examining the recovery of infectious influenza virus from experimentally virus-contaminated clothing, which had been subejected to routine wearing and washing for several months or years. The amount of infectious virus recovered from the nine types of clothing decreased with time and was shown to differ widely between clothing samples, when the contaminated clothing samples were maintained in uncovered glass Petri dishes in a safety cabinet under air blowing. These results indicate a dependence of virus transmissibility on the nature of the contaminated clothes. The difference in recovery was shown to have no significant correlation with the thickness or the materials of the clothing; however, a correlation was observed with the residual amount of water in the deposited virus preparation on the test clothing.

Alumina coating of polyvinylidene fluoride (PVDF) surface in liquid phase

A two-step procedure is developed for preparing alumina coated polyvinylidene fluoride particles (diameter, ∼100 μm) whose chemically inert and non-adhesive surface is initially grafted with polystyrene. The first coating step involves deposition of alumina precipitation centres into the polystyrene layer using the reaction of trimethylaluminium with a small residual amount of water retained within the porous brushy polystyrene structure after incomplete drying of the particles. The second coating step is performed through gentle precipitation of aluminium hydroxide from an aqueous aluminium chloride solution, with the alumina deposition being directed by the precipitation centres implanted during the first step. As a result of this process, the particles are covered uniformly with inorganic material. The quality and thickness of the final coating layer are controlled by the precipitation rate and stirring conditions.

Phosphonate- and Carboxylate-Based Self-Assembled Monolayers for Organic Devices: A Theoretical Study of Surface Binding on Aluminum Oxide with Experimental Support

We report a computational study on the chemical bonding of phosphonates and carboxylates to aluminum oxide surfaces and how the binding properties are related to the amount of water in the experimental environment. Two different surface structures were used in the calculations in order to model representative adsorption sites for the phosphonates and carboxylates and to account for the amorphous nature of the hydroxylated AlOx films in experiment. For the phosphonates, we find that the thermodynamically preferred binding mode changes between mono-, bi-, and tridentate depending on the surface structure and the amount of residual water. For the carboxylates, on the other hand, monodentate adsorption is always lower in energy at all experimental conditions. Phosphonates are more strongly bound to aluminum oxide than carboxylates, so that carboxylates can be replaced easily by phosphonates. The theoretical findings are consistent with those obtained in adsorption, desorption, and exchange reactions of n-alkyl phosphonic and carboxylic acids on AlOx surfaces. The results provide an atomistic understanding of the adsorption and help to optimize experimental conditions for self-assembly of organic films on aluminum oxide surfaces.

A fully coupled diffusion-reaction scheme for moisture sorption–desorption in an anhydride-cured epoxy resin

Thermoset materials frequently display non-classical moisture sorption behaviors. In this paper, we investigated this issue from an experimental point of view as well as in terms of modeling the water transport. We used the gravimetric technique to monitor water uptake by epoxy samples, with several thicknesses exposed to different levels of humidity during absorption and desorption tests. Our results revealed that the polymer displays a two-stage behavior with a residual amount of water that is desorbed progressively. We proposed a phenomenological reaction-diffusion scheme to describe this behavior. The model describes water transport as a competition between diffusion and the reaction, during which the local diffusivity and solubility depend on the local advancement of the reaction. We then implemented our model using COMSOL Multiphysics and identified it using a MATLAB-COMSOL optimization tool and the experimental data. We discussed the relation between the hydrophilicity of the product of the reaction and the diffusion behavior. We examined the reaction-induced modification of the water concentration field. It is worth noting that part of the phenomenology can be explained by the presence of hydrolyzable groups.

Occurrence of residual water within disk-based solid-phase extraction and its effect on GC-MS measurement of organic extracts of environmental samples

Solid-phase extraction (SPE) is a widespread and powerful sample preparation technique in many analytical areas. Many of the used methods reduce residual water during sample preparation by drying the phase material. Despite the importance of this step, hardly any study deals specifically with the drying process, and if so, only few aspects are mentioned. The present study is the first systematic investigation of the drying process using SPE disks, including the influence of process parameters on the amount of residual water and its consequences for subsequent elution and gas chromatography-mass spectrometry (GC-MS) analysis. The following points were investigated in detail: (1) the change of pressure and volume flow during the drying process, (2) the remaining amount of water at different drying times for different SPE materials, (3) the influence of suspended particulate matter on the drying process and (4) the effects of the residual water on the elution step by using different organic solvents. The study shows that the volume of residual water in the SPE disk is affected by the fixation of the sorbent, the phase material, the amount of sorbent, the pumping settings and the duration of the drying process. Furthermore, systematic investigations demonstrate the influence of residual water on the GC-MS analysis and show analytical interferences only for a few of the investigated analytes. All results suggest that more problems in SPE GC-MS methods are caused by residual water than previously assumed.

Three-dimensional Magnetic Resonance Imaging of fossils across taxa

Abstract. The frequency of life forms in the fossil record is largely determined by the extent to which they were mineralised at the time of their death. In addition to mineral structures, many fossils nonetheless contain detectable amounts of residual water or organic molecules, the analysis of which has become an integral part of current palaeontological research. The methods available for this sort of investigations, though, typically require dissolution or ionisation of the fossil sample or parts thereof, which is an issue with rare taxa and outstanding materials like pathological or type specimens. In such cases, non-destructive techniques could provide a valuable methodological alternative. While Computed Tomography has long been used to study palaeontological specimens, a number of complementary approaches have recently gained ground. These include Magnetic Resonance Imaging (MRI) which had previously been employed to obtain three-dimensional images of pathological belemnites non-invasively on the basis of intrinsic contrast. The present study was undertaken to investigate whether 1H MRI can likewise provide anatomical information about non-pathological belemnites and specimens of other fossil taxa. To this end, three-dimensional MR image series were acquired from intact non-pathological invertebrate, vertebrate and plant fossils. At routine voxel resolutions in the range of several dozens to some hundreds of micrometers, these images reveal a host of anatomical details and thus highlight the potential of MR techniques to effectively complement existing methodological approaches for palaeontological investigations in a wide range of taxa. As for the origin of the MR signal, relaxation and diffusion measurements as well as 1H and 13C MR spectra acquired from a belemnite suggest intracrystalline water or hydroxyl groups, rather than organic residues.