Problems of informational support of chemical and radiation ecological monitoring of long-term technological storage of reactor blocks of utilized submarines afloat in the northwestern region

Complexity of the problems related to utilization of nuclear submarines (NSM) is determined not only by their huge scale but also by the necessity of systemic consideration of diverse factors, including political, economic, ecological, social, technological, and informational. Afloat storage of reactor compartment units is a complex chemical, technological and ecological problem, for sea water induces their extensive corrosion which creates a risk of leakage of radioactive heavy metal isotopes, fission products, and transuranium elements to the environment. While searching for and testing of technological solutions for utilization of NSM, the most important problems are chemical and radiation ecological monitoring of water areas and its informational support. The article contains systemic analysis of problems related to long-term technological storage of reactor compartment units afloat, and an optimal procedure for ecological radionuclide monitoring is proposed. The proposed procedure requires minimal equipment and radiation control range but ensures a sufficient confidence level.     

Assay for oxygen in uranium in the 0.1–1.0 wt% range using 14-MeV neutron activation

The X-ray spectrometric method for uranium determination in sea water is discussed. Two techniques of uranium enrichment are presented: (1) precipitation with the chelating agent ammonium-1-pyrrolidine dithiocarbamate (APDC) in the presence of iron(II) as a carrier and (2) complexation with APDC followed by adsorption on activated carbon. The best pH range and the other optimized conditions for uranium determination in sea water with both methods are reported.     

Reference materials for monitoring nutrients in sea water environment

VKI, the Danish national reference laboratory for environmental chemistry, has prepared a range of reference materials for quality control of nutrient analyses in environmental samples. The relevant concentration levels and potential matrix interference effects vary with the sample type. In sea water, nutrient concentrations are in the g/L range and salt concentrations can cause matrix interferences. Two certified reference materials for nutrient analyses were prepared representing the salinities in the Kattegat (20–25 parts per thousand) and the Baltic sea (below 10 parts per thousand). The preparation and certification were an integrated part of a larger project conducted by VKI on the optimisation of nutrient analyses in sea water. Part of the project has been participation in a European interlaboratory trial exercise QUASIMEME [1], which has enabled the Danish reference material data to be traced back to other European data. Denmark has now a certified reference material that will help to ensure the quality of marine analyses that are part of the ongoing national water monitoring plan.     

Successive high-precision determination of calcium and magnesium in sea water with a new probe photometer

A high-precision method for determining calcium and magnesium successively in sea water is described. The calcium end-point is evaluated with zinc—zincon as indicator, while magnesium is determined with calcon. The computerized method utilizes a new probe photometer based on modern optoelectronic components. The precision for calcium and magnesium is 0.3 ‰ and 0.4 ‰, respectively.     

Ultra-trace determination of aquaculture chemotherapeutants and degradation products in environmental matrices by LC-MS/MS

Two of the most common products currently used to control parasitic sea lice in fin fish aquaculture, salmon in particular, are Slice® and AlphaMax®. Emamectin benzoate (EB) is the active ingredient in Slice® and deltamethrin is the active ingredient in AlphaMax®. Several analytical methods have been developed for the determination of the active ingredients in these products but these have been focused on specific matrices and lack the sensitivity and versatility required in environmental monitoring. Here we present a validated, versatile, and simple analytical method for the determination of EB, its desmethyl degradation product (AB), and deltamethrin in a wide range of environmental matrices (sea water, marine sediment, and tissue). Sediments and tissues were extracted by accelerated solvent extraction (ASE®) and sample cleanup was achieved by solid phase extraction (SPE) while sea water was extracted using SPE disks. Analyte identification and quantification was based on liquid chromatography tandem mass spectrometry (LC-MS/MS) instrumentation with electrospray ionization, and multiple reaction monitoring (MRM). Method detection limits for the target analytes was in the parts per trillion (pg?g^?1) level for tissue and sediment and parts per quadrillion (pg?L^?1) for water. Except for deltamethrin in sea water, method performance in terms of analyte recoveries was better than 60%, and the method precision was RSD<20%. The method was used to determine EB and AB concentrations in water, sediment and prawn tissue samples collected near salmon aquaculture sites treated with Slice®. A distinct concentration gradient was observed in the immediate vicinity (within 50 to 100?m radius) of the salmon aquaculture sites where EB was detected at low ng?g^?1 levels for tissue (EB ranged from 0.041 to 3.0?ng?g^?1) and sediment (EB ranged from 0.051 to 35?ng?g^?1) and pg?L^?1 levels (EB ranged from 3 to 209?pg?L^?1) for water samples.     

Detector for particulate polycyclic aromatic hydrocarbons in water

It is estimated that most polycyclic aromatic hydrocarbons (PAHs) in environmental water are not dissolved but rather in particulate form. Nevertheless, the currently available optical detectors are not suited for proper sampling of solid PAHs. A new setup for direct sampling and quantification of suspended particulate PAHs in water is suggested. It is based on a polymeric film that has the capability of dissolving PAH particulates, coupled to a traditional laser-induced fluorescence probe. Kinetics and performance of two sampling modes have been studied: bulk sampling, by immersing the probe into the water, and surface sampling, by laying the film on the water surface. The latter method has proved to be more sensitive; however, it is diffusion-limited. Linear calibration plots have provided quantification over a wide concentration range with detection limits in the ppb range (these could be improved by using a modified probe). The effects due to other particulates in water have been studied and only little interferences have been observed. The possibility of analysis of PAH mixtures has been addressed and it has been concluded that multivariate analysis is needed.     

Single-crystal sapphire-fiber optic sensors based on surface plasmon resonance spectroscopy for in situ monitoring

Single-crystal sapphire-fiber optic sensors based on surface plasmon resonance (SPR) for refractive index (RI) measurements of aqueous and hydrothermal water solutions are described. Accurate measurement of RIs is essential to efficient operation and control of broad range of engineering processes. Some of these processes are carried out with harsh environments, such as high-temperature, high pressure, and chemical corrosion. These extreme physical conditions are proving a limiting factor in application of the conventional silica-based optical sensors. Single-crystal sapphire is an ideal material for sensor applications, where reliable performance is required in the extreme environment conditions. With regard to the liquid species detection, most applications of SPR sensors are designed to function near the refractive index of water (1.3330 RI). The RI changes of aqueous solution can be easily monitored by silica-fiber (RI, 1.4601 at 550 nm) based SPR sensor. However, the sapphire waveguide has a prohibitively high RI (1.7708 at 546 nm) for unmodified monitoring of the RI changes of aqueous solutions. For that purpose, a practical SPR probe geometry has been applied to the ability to tune the SPR coupling wavelength/angle pair with sapphire-fiber based SPR probe.     

Anodic stripping voltammetry in a flow-through cell with fixed mercury film glassy carbon disc electrodes part II. the differential mode (D.A.S.V.)

Differential anodic stripping voltammetry at a fixed glassy carbon disc electrode covered by a thin mercury film, was adapted for use in a flow-through cell. Improved sensitivity, arising from virtually perfect compensation of background currents, is demonstrated by presenting the application of the method to the determination of heavy metal ions (hydrates and/or in a labile complex form), in the 0.1–1 ng ml^?1 concentration range, in sea water, using short (1–6 min) deposition periods. Good precision of results is maintained; calibration curves, within the a.m. concentration range, are linear. Due to simplicity and stability, the system seems well suited for continuous monitoring in aqueous media.     

A battery-powered,computerized instrument for the field-based determination of fluoride by the ion-selective electrode technique

Battery-powered complementary metal-oxide semiconductor (CMOS) electronic devices are used to develop computerized instrumentation based on an ion-selective electrode for environmental monitoring in the field. The development of CMOS-based instrumentation for the determination of fluoride in drinking water, river water, lake water and sea water is described. The instrument is portable and completely field-programmable. Under software control, the equilibrium potential and fluoride concentration, based on a double standard-addition method, are calculated. The associated temperature, date and time form part of the data-logging record. Data obtained in the field are shown to compare satisfactorily with those obtained on samples which were stored and returned to the laboratory for examination by conventional mains-powered instrumentation. Accuracy is good and precision is only slightly poorer than that of mains-powered laboratory instrumentation.     

A Water Soluble 2-Phenyl-5-(pyridin-3-yl)-1,3,4-oxadiazole Based Probe: Antimicrobial Activity and Colorimetric/Fluorescence pH Response

The growing demand of responsive tools for biological and biomedical applications pushes towards new low-cost probes easy to synthesize and versatile. Current optical probes are theranostic tools simultaneously responsive to biological parameters/analyte and therapeutically operating. Among the optical methods for pH monitoring, simple small organic molecules including multifunctional probes for simultaneous biological activity being highly desired by scientists and technicians. Here, we present a novel pH-responsive probe with a three-ring heteroaromatic pattern and a flexible cationic chain. The novel molecule shows real-time naked-eye colorimetric and fluorescence response in the slightly acidic pH range besides its excellent solubility both in the organic phase and in water. In addition, the small probe shows significant antibacterial activity, particularly against Escherichia coli. Single-crystal X-ray study and density functional theory (DFT) calculations rationalize the molecule spectroscopic response. Finally, molecular dynamics (MD) elucidate the interactions between the probe and a model cell membrane.     

Quantitative Determination of Water in Organic Liquids by Ambient Mass Spectrometry

This study uses a rapid tandem mass-spectrometry method to determine water content in complex organic solutions. Emphasis is placed on trace-water analysis by a fast and accurate alternative to the Karl–Fischer method. In this new method, water is captured by a charge-labeled molecular probe. Water binds strongly with high specificity to the strongly electrophilic aldehyde site in a charge-labelled molecule (N-methylpyridinium); competitive binding by other analytes is effectively discriminated against in the mass-measurement step. Quantitative determinations are made over a wide concentration range, 0.001 % (10 ppm) to 99 %, with better than 10 % relative standard deviation, along with short (1 min) analysis times using small sample volumes (several μL). Applications include water measurement in simple organic solvents, for example, deuterated solvents, as well as in complex mixtures, for example, organic reaction mixtures. Additionally, this method allows for water monitoring in levitated droplets. Mechanistic investigations into the impact of water on important chemical processes in organic synthesis and environmental science are reported.     

A Metallosupramolecular Coordination Polymer for the ‘Turn-on’ Fluorescence Detection of Hydrogen Sulfide

A coumarin based probe for the efficient detection of hydrogen sulfide in aqueous medium is reported. The investigated coumarine-based derivative forms spherical nanoparticles in aqueous media. In presence of Pd²⁺, a metallosupramolecular coordination polymer is formed, which is accompanied by quenching of the coumarin emission at 390 nm. Its Pd²⁺ complex could be used as a probe for chemoselective detection of monohydrogensulfide (HS⁻). Presence of HS⁻ leads to a'turn-on' fluorescence signal, resulting from decomplexation of Pd²⁺ from the metallosupramolecular probe. The probe was successfully applied for qualitative and quantitative detection of HS⁻ in different sources of water directly collected from sea, river, tap and laboratory drain water, as well as in growth media for aquatic species.     

A sensitive colorimetric method for the micro determination of iodine in marine water

More than 70% of the earth surface is covered by water bodies. Marine pollution is associated with the discharge of oils, petroleum products, sewage agricultural wastes, pesticides, heavy metals, waste substances and dumping of radioactive waters in sea. This in turn results in hazards to human health, hindrance to aquatic organisms and impairment of quality for use of sea water. Sea water is reported to contain iodine but the concentration varies according to the location and depth. Here a simple and sensitive method is described for the determination of iodine using leucocrystal violet as a reagent in different samples of sea water. The method is based on the oxidation of iodine to iodate with bromine water and the liberation of free iodine from the iodate by addition of potassium iodide in acedic medium. This iodine selectively oxidises leucocrystal violet to form the crystal violet dye. Beer's law is obeyed over the concentration range of 0.04-0.36 ppm of iodine at lambda(max) 592 nm. The dye was further extracted in chloroform. The extracting system obeys Beer's law in the range of 0.008-0.08 ppm at lambda(max) 588 nm.     

Fluorescence sensors for trace monitoring of dissolved ammonia

Even though monitoring of dissolved ammonia is acutely important for environmental studies, fish farms and for industrial surveillance, no system for the performance of online measurements at the concentrations needed exists so far. For many applications it is necessary to detect dissolved ammonia concentrations at sub mg/l-levels, because ammonia is reported to be toxic for aquatic organisms above 25 microg/l. We present new ammonia sensitive materials consisting of fluorescent pH indicators embedded into different cellulose esters. The low pK(a) value of the indicators and the high solubility of ammonia in the cellulose polymers lead to detection limits below 1 microg/l and a dynamic range between 5 and 1000 microg/l. Response times at these trace concentration levels are in the order of 20-30 min. The sensors are suitable for fresh and sea water monitoring by an additional silicon layer preventing the interference of protons and salinity. The fluorescent indicators Eosin ethylester and 2',7'-dichlorofluorescein methylester (DCF) were investigated to achieve sensors with a dynamic range matching the target concentrations. Sensors with improved performance were obtained by employing cellulose ester nanospheres with incorporated Eosin ethylester. The simple sensor design has a high potential to be applied in miniaturized optical measurement system for online ammonia detection.     

A system for taking a representative sample from a large volume of turbid surface sea water for trace element determinations

The sampler is designed for use in routine monitoring of dissolved and particulate trace metals (Zn, Cd, Pb, Cu, Sb and Bi) in turbid sea water. By continuous horizontal sampling, the 5-l volume of sea water actually collected is representative of a very large volume (3000 1). The system includes pumping and filtration apparatus, suitable for use by unskilled operators, to collect small liquid and particulate samples in a closed system precluding atmospheric contamination. Filtration (0.45-μm filter) under pressure makes it possible to collect 50–100 mg of suspended matter from shallow water within 45 min. Tests under routine working conditions show satisfactory results.     

Polymer film sensor for sampling and remote analysis of polycyclic aromatic hydrocarbons in clear and turbid aqueous environments

A sensor for remote analysis of polycyclic aromatic hydrocarbons (PAHs) has been developed. It is based on direct solid phase extraction of the pollutants on a polymeric film, followed by monitoring the laser induced fluorescence, emitted from the film, via optical fibers. The proposed sensor has been applied to direct PAH analysis in clear and turbid aqueous environments. Linear calibration plots have been obtained for PAH solutions containing both humic substances and clay suspensions. Detection limits in the range of 10 ppt have been achieved. Results are obtained almost instantaneously (in drinking water) or within minutes, in more complicated matrices. This set-up has provided considerable improvement of the detection limits, when compared to the traditional fiber-optic fluorescence probe. In case of pyrene, a 100-fold and a 250-fold improvement in the detection limits have been obtained for the clay and humic substances-containing water, respectively. The spectral response of the polymeric film has been studied under various conditions and the feasibility of the method for analysis of PAH mixtures has been addressed.     

On-line monitoring of biotechnological processes by gas chromatographic-mass spectrometric analysis of fermentation suspensions

An on-line monitoring system has been developed for the control of a biorreactor for the anaerobic pretreatment of an industrial waste water. The monitoring system is based on a process mass spectrometer with a temperature controlled membrane inlet. The membrane introduction mass spectrometer (MIMS) is coupled with a resistively heated metal gas chromatography capillary column, which serves as a transfer line between the bioreactor and the MIMS. Sampling and injection is performed by means of a pneumatically driven membrane probe, which enables monitoring of soluted and gaseous substances in the fermentation broth. The system can also be coupled to other processes.     

A Hg(II)-specific probe for imaging application in living systems and quantitative analysis in environmental/food samples

Mercury ions are highly toxic and can accumulate along food chains in water, soil, crops and animals. Effective detection of mercury ions in various media is of great significance for maintaining the ecological environment and protecting people’s health. In this work, a mercury ions specific fluorescent probe was developed by a simple one-step reaction of commercial substrates of 4-chloro-7-nitro-2,1,3-benzoxadiazole and 1-(2-aminoethyl)-4-methylpiperazine. Investigation on sensing behavior showed that this probe had high sensitivity and selectivity towards mercury ions. Furthermore, this probe could be used as a tool to track the level of mercury ions in living system. In living cells, the probe with green emission emitted a bright red fluorescence when it was bound to mercury ions. In Arabidopsis thaliana, similar red emission could be detected from the root tip and stalk when A. thaliana was grown in culture medium containing mercury ions. The imaging in zebrafish showed that mercury ions were mainly concentrated in the stomach and head of zebrafish. Especially, this probe could be applied in quantitative analysis of mercury ions in tap water, green tea, sea shrimp and soil. This work provided a practical tool for the detection of mercury ions in living systems and quantitative analysis in real samples.     

Microchemical determination of lodate and iodide in sea waters by flow injection analysis

A flow injection analysis method for iodate and iodide in sea water is described. The system involves spectrophotometric detection based on the catalytic, fading effect of either iodate or iodide on the indicator reaction of iron (III) thiocyanate and nitrite. With and without an anion-exchange column in the flow conduit, the system allows the determination of iodate and total iodine, respectively; iodide can be found by difference. Both iodate-iodine and total iodine can be determined in the range 0.75 to 150 g/1 on the sea water basis with analysis times of 20 min for iodate-iodine and 9 min for total iodine. The RSDs are within 1.3% for both iodate and iodide. Results are presented for the determination of iodate and iodide in sea waters and some brines associated with natural methane gas evolution.