Long-Term Experimental Manipulation of Atmospheric Sulfate Deposition to a Peatland: Response of Methylmercury and Related Solute Export in Streamwater.

Changes in sulfate (SO) deposition have been linked to changes in mercury (Hg) methylation in peatlands and water quality in freshwater catchments. There is little empirical evidence, however, of how quickly methyl-Hg (MeHg, a bioaccumulative neurotoxin) export from catchments might change with declining SO deposition. Here, we present responses in total Hg (THg), MeHg, total organic carbon, pH, and SO export from a peatland-dominated catchment as a function of changing SO deposition in a long-term (1998-2011), whole-ecosystem, control-impact experiment.

Introducing comprehensive multiphase NMR for the analysis of food: Understanding the hydrothermal treatment of starch-based foods.

Cooking is essential for preparing starch-based food, however thermal treatment promotes the complexation of biopolymers, impacting their final properties. Comprehensive Multiphase (CMP) NMR allows all phases (liquids, gels, and solids) to be differentiated and monitored within intact samples. This study acts as a proof-of-principle to introduce CMP-NMR to food research and demonstrate its application to monitor the various phases in spaghetti, black turtle beans, and white long-grain rice, and how they change during the cooking process.

Exploring the Applications of Carbon-Detected NMR in Living and Dead Organisms Using a C-Optimized Comprehensive Multiphase NMR Probe.

Comprehensive multiphase-nuclear magnetic resonance (CMP-NMR) is a non-invasive approach designed to observe all phases (solutions, gels, and solids) in intact samples using a single NMR probe. Studies of dead and living organisms are important to understand processes ranging from biological growth to environmental stress. Historically, such studies have utilized H-based phase editing for the detection of soluble/swollen components and H-detected 2D NMR for metabolite assignments/screening.

Evaluation of double-tuned single-sided planar microcoils for the analysis of small C enriched biological samples using H- C 2D heteronuclear correlation NMR spectroscopy.

Microcoils provide a cost-effective approach to improve detection limits for mass-limited samples. Single-sided planar microcoils are advantageous in comparison to volume coils, in that the sample can simply be placed on top. However, the considerable drawback is that the RF field that is produced by the coil decreases with distance from the coil surface, which potentially limits more complex multi-pulse NMR pulse sequences.

Comprehensive Multiphase NMR Probehead with Reduced Radiofrequency Heating Improves the Analysis of Living Organisms and Heat-Sensitive Samples.

Comprehensive multiphase (CMP) NMR, first described in 2012, combines all of the hardware components necessary to analyze all phases (solid, gel, and solution) in samples in their natural state. In combination with spectral editing experiments, it can fully differentiate phases and study the transfer of chemical species across and between phases, providing unprecedented molecular-level information in unaltered natural systems. However, many natural samples, such as swollen soils, plants, and small organisms, contain water, salts, and ionic compounds, making them electrically lossy and susceptible to RF heating, especially when using high-strength RF fields required to select the solid domains.

Expanding current applications and permitting the analysis of larger intact samples by means of a 7 mm CMP-NMR probe.

Comprehensive multiphase NMR combines the ability to study and differentiate all phases (solids, gels, and liquids) using a single NMR probe. The general goal of CMP-NMR is to study intact environmental and biological samples to better understand conformation, organization, association, and transfer between and across phases/interfaces that may be lost with conventional sample preparation such as drying or solubilization. To date, all CMP-NMR studies have used 4 mm probes and rotors.

Comprehensive Multiphase NMR of whole organisms: A complementary tool to NMR.

Nuclear Magnetic Resonance (NMR) spectroscopy is a non-invasive analytical technique which allows for the study of intact samples. Comprehensive Multiphase NMR (CMP-NMR) combines techniques and hardware from solution state and solid state NMR to allow for the holistic analysis of all phases (i.e.

5-Axis CNC Micromilling for Rapid, Cheap, and Background-Free NMR Microcoils.

The superior mass sensitivity of microcoil technology in nuclear magnetic resonance (NMR) spectroscopy provides potential for the analysis of extremely small-mass-limited samples such as eggs, cells, and tiny organisms. For optimal performance and efficiency, the size of the microcoil should be tailored to the size of the mass-limited sample of interest, which can be costly as mass-limited samples come in many shapes and sizes. Therefore, rapid and economic microcoil production methods are needed.

Targeting the Lowest Concentration of a Toxin That Induces a Detectable Metabolic Response in Living Organisms: Time-Resolved 2D NMR during a Concentration Ramp.

nuclear magnetic resonance (NMR) is a powerful analytical tool for probing complex biological processes inside living organisms. However, due to magnetic susceptibility broadening, which produces broad lines in one-dimensional NMR, H-C two-dimensional (2D) NMR is required for metabolite monitoring . As each 2D experiment is time-consuming, often hours, this limits the temporal resolution over which processes can be monitored.

Understanding the Fate of Environmental Chemicals Inside Living Organisms: NMR-Based C Isotopic Suppression Selects Only the Molecule of Interest within C-Enriched Organisms.

In vivo nuclear magnetic resonance (NMR) is rapidly evolving as a critical tool as it offers real-time metabolic information, which is crucial for delineating complex toxic response pathways in living systems. Organisms such as (water fleas) and (freshwater shrimps) are commonly C-enriched to increase the signal in NMR experiments. A key goal of in vivo NMR is to monitor how molecules (nutrients, contaminants, or drugs) are metabolized.

Selective Amino Acid-Only in Vivo NMR: A Powerful Tool To Follow Stress Processes.

In vivo NMR of small C-enriched aquatic organisms is developing as a powerful tool to detect and explain toxic stress at the biochemical level. Amino acids are a very important category of metabolites for stress detection as they are involved in the vast majority of stress response pathways. As such, they are a useful proxy for stress detection in general, which could then be a trigger for more in-depth analysis of the metabolome.

C quantification in heterogeneous multiphase natural samples by CMP-NMR using stepped decoupling.

Many natural and environmental samples contain combinations of liquids, gels, and solids, yet quantification in the intact state and across multiple phases is highly challenging. Comprehensive multiphase nuclear magnetic resonance (CMP-NMR) combines all the capabilities of high-resolution magic angle spinning (HR-MAS), with the addition of full solids power handling, permitting all phases (i.e.

Strontium adsorption and desorption in wetlands: Role of organic matter functional groups and environmental implications.

Strontium (Sr) is a chemical element that is often used as a tracer in hydrogeochemical studies, and is ubiquitously distributed as a radioactive contaminant in nuclear sites in the form of strontium-90 (Sr-90). At the interface between groundwater and surface water, wetlands possess unique hydrogeochemical properties whose impact on Sr transport has not been investigated thoroughly. In this study, the adsorption and desorption of Sr was investigated on six natural wetland substrates and two mixes of exogenous media and wetland sediment: winter and summer wetland sediments, decayed cattails, wood, leaf litter, moss, bone charcoal, and clinoptilolite.