Springer最新文献

The widespread presence of pharmaceuticals, including antibiotics, in our aquatic environment raises important societal concerns. When studying their environmental fate, stable isotope analysis of nitrogen and carbon at natural abundance offers unique insight into source fingerprinting and degradation-associated kinetic isotope effects. Here, we synthesized compound-specific reference standards to enable electrospray ionization (ESI) Orbitrap mass spectrometry (MS) for fragment-specific carbon and nitrogen isotope analysis (Δδ¹³C and Δδ¹⁵N) of sulfamethoxazole (SMX), a most frequently detected antibiotic. Fragment-specific isotope analysis relied on fragmentation of SMX ions in the collision cell, resulting in two fragment ions representing the aniline part (m/z = 92, F92) and the 3-amino-5-methylisoxazole ring (m/z = 99, F99) of SMX. Reference materials were prepared (i) through total synthesis of SMX from labeled precursors that resulted in specific positions labeled with ¹³C and ¹⁵N, (ii) followed by the mixing of labeled SMX with SMX at natural abundance. The bulk isotope values of these in-house standards were determined by elemental analysis isotope ratio mass spectrometry and used for calibration of the ESI-Orbitrap-MS method. Injecting standards directly into the ESI-Orbitrap-MS resulted in 95% confidence intervals (CIs) of 0.7‰ and 3.4‰ for Δδ¹³C and Δδ¹⁵N in F92, respectively, and 1.3‰ and 2.9‰ for Δδ¹³C and Δδ¹⁵N in F99, for quintuplicate measurements of standards. A proof-of-principle demonstration shows that this approach could indeed successfully quantify changes in fragment-specific isotopic signatures, Δδ¹³C and Δδ¹⁵N, during degradation of SMX.

Trigonelline is an alkaloidal plant derived bioactive compound reported for its various pharmacological activities. Recent advances in the utilization of this compound in drug development have highlighted the importance of establishing a reproducible and efficient analytical method for estimating trigonelline (TRG) in both its pure form and formulated nano systems. Current research aims to develop and validate a green RP-HPLC method for estimating TRG by integrating Analytical Quality by Design (AQbD) with the principles of Green Analytical Chemistry. Optimization of the chromatographic conditions was done by employing a rotatable central composite design with amount of mobile phase and its flow rate selected as critical variables and tailing factor (T_f), retention time (R_t) and theoretical plates as the responses. Optimal separation was achieved using ethanol and water (40:60, v/v) on a Phenomenex C18 (250 × 4.6 mm, 5 μm) column at 264 nm, yielding a sharp, symmetric peak at 5.60 min at a flow rate of 1.5 mL/min. Developed method exhibited excellent linearity over the range of 5-15 µg/mL (r² = 0.9986) with %RSD less than 2% and LOD & LOQ were found to be 0.628 µg/mL and 1.90 µg/mL, respectively. Forced degradation studies showed 12% degradation in acidic media and 9% in alkaline media after exposure of 8 h indicating moderate susceptibility to hydrolysis. Further, the validation was performed for the developed method according to ICH Q2(R1) guidelines. A comprehensive greenness assessment was performed using AES, GAPI, AGREE, AMGS, and AGSA tools, confirming that the newly developed method demonstrates superior greenness and its suitability for sustainable routine analysis compared to existing methods.

Nanoflow electrospray ionization is commonly used for proteomics due to its high sensitivity. Signal intensity, however, is dependent on optimal emitter positioning relative to the mass spectrometer inlet. Here, we characterize the effect of varied emitter positions on peptide signal intensity in all three dimensions using emitters and flows consistent with standard proteomic analyses. We observe improved signal robustness to x/y variations at increasing z distances and demonstrate that positioning within 1 to 2 mm of the optimal location will maintain consistent signal. Signal intensity behavior is consistent across the m/z range, suggesting emitter positions do not need to be fine-tuned for different analytes for proteomics analyses. These results provide insight for proteomics researchers using nanoflow LC-MS/MS.

Urban expansion escalates both light and air pollution, posing significant threats to environmental health and energy sustainability. This study presents a spatiotemporal analysis of light pollution in Antalya, Turkey, and explores its relationship to urban air quality. Using ground-based measurements from a sky quality meter (SQM), clouds masks from EUMETSAT, and satellite data from NASA's Black Marble, a comprehensive analysis of night sky brightness and its long-term trends was conducted from 2012 to 2023. Analysis of annual composites identified specific development projects, such as a new hospital and airport expansion, as major sources of increased brightness, with total radiance consistently rising across all districts, reflecting urban sprawl. The relationship between particulate matter (PM2.5) and satellite-observed radiance was examined using data from four ground-based air quality monitoring stations. Despite filtering for clear-sky conditions and moonlight, no statistically significant correlation was found on monthly or daily timescales. This null result likely reflects the decoupling between surface-based PM2.5 measurements and the vertically integrated aerosol column influencing satellite-observed radiance. Upward radiant flux was also quantified to estimate a lower bound in terms of electric cost. Our findings highlight the impact of rapid urbanization on light pollution and provide a baseline for developing targeted mitigation strategies, while indicating that the interplay with air quality in this region is complex.

Aqueous zinc batteries are gaining attention as promising alternatives to Li-ion systems, owing to the increased need for safe and cost-effective energy storage. Aqueous Zn-halogen batteries are particularly important because of their low cost and the abundance of precursors. However, critical challenges, such as the shuttle effect, sluggish redox kinetics, and dendrite growth, impede their practical development. Metal-organic frameworks (MOFs) with high porosity, ease of functionalization, and stability offer a multifunctional approach to overcome these limitations. This review systematically examines the advancements in MOF-based Zn-halogen batteries, focusing on their roles in different components of the battery, including the cathode, anode, and separator. This review also highlights the key design strategies for MOF-based materials and then examines the structure-performance relationships through advanced characterization and computational insights. The remaining challenges and future directions are also outlined. Overall, this review provides a roadmap for developing advanced MOF-based Zn-halogen batteries that combine high energy density and long-term durability for next-generation energy storage applications.