As one of the key components in technetium-labeled radiopharmaceuticals, the quality of the dimercaptosuccinate (DMSA) plays a critical role in determining the safety and efficacy of the final drug product. However, due to its high polarity and susceptibility to oxidation, comprehensive characterization of the impurity profile of DMSA remains challenging. In this study, high-performance liquid chromatography and mass spectrometry were employed to achieve a systematic and thorough analysis of DMSA-related impurities. First, an HPLC-UV method was developed to enable baseline separation of DMSA and its impurities. Subsequently, a two-dimensional liquid chromatography–tandem mass spectrometry (2D-LC-MS/MS) approach was applied to identify six structurally diverse impurities present in DMSA. The developed HPLC method was rigorously validated and demonstrated to be sensitive, robust, and suitable for the accurate quantification and detection of trace impurities. Using the validated method, DMSA raw materials sourced from multiple manufacturers were analyzed, revealing significant variability in their impurity profiles. These findings underscore the importance of stringent quality control measures for DMSA in radiopharmaceutical manufacturing. This work not only establishes a reliable analytical framework for impurity profiling and structural elucidation of DMSA but also provides valuable insights for the development of quality control strategies and process optimization of radiopharmaceuticals.

Intensive calcination, selection and metallurgical joint comprehensive utilization of solid waste blast furnace gas ash generated by a Chinese iron and steel plant. The main valuable elements in the gas ash are Fe, Pb, Zn, and C, with contents of 22.46%, 3.22%, 10.57%, and 27.02%, respectively. The iron minerals are mainly magnetite and hematite/limonite. Lead exists primarily in the form of lead vanadate and basic lead chloride. Zinc is associated with oxygen, sulfur, and iron in the form of zinc ferrite crystals. The effects of calcination temperature, calcination time, and reducing agent dosage on gasification and reduction indices were investigated. Results showed that using a gasification and reduction calcination–magnetic separation process with weak magnetism, at a calcination temperature of 1150 °C, with 20% anthracite as the reducing agent and a calcination time of 2 h, the volatilization rates of lead and zinc reached 96.70% and 98.26%, respectively. When the roasted ore was ground to a particle size of D90 = 0.085 mm, high-quality iron concentrate with 65.61% iron grade and low lead and zinc contents of 0.08% and 0.17% was obtained, meeting the quality requirements for iron concentrate. The tailings from iron selection can be used as additives in cement and other construction materials. This integrated process combining pyrometallurgy and mineral processing enables the efficient and comprehensive utilization of blast furnace gas dust.

The extensive use of antiviral substances (SASs) during and after the COVID-19 pandemic has increased their release into wastewater systems, raising concerns regarding their persistence and potential ecotoxicological effects. The primary objective of this study was to isolate bacterial strains from activated sludge (AS) that possess the ability to biodegrade SASs. From the AS sample, three bacterial species, Comamonas testosteroni (I2), Bacillus amyloliquefaciens (I3) and Bacillus mycoides (I4), were successfully isolated and identified. These strains were subsequently applied in biodegradation experiments targeting seven SASs: daclatasvir (DCV), darunavir (DRV), favipiravir (FAV), lopinavir (LOP), remdesivir (REM), ritonavir (RIT), and umifenovir (UMI). During the experiments, residual SAS concentrations, microbial growth parameters, physicochemical indicators and ecotoxicity were monitored. All three strains demonstrated substantial biodegradation potential, achieving reductions exceeding 90% for most tested compounds, with particularly low toxicity observed in experiments conducted with AS and Bacillus amyloliquefaciens. These findings highlight the relevance of AS-derived bacteria as promising candidates for enhancing SAS removal in wastewater treatment processes.

A robust and stability-indicating Reverse Phase-High Performance Liquid Chromatography (RP-HPLC) method was developed and validated for the quantitative determination of bexagliflozin and its related impurities in accordance with the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH Q2(R1)) guidelines. Chromatographic separation was achieved on a C18 column using a mobile phase of methanol and ammonium acetate buffer (pH 4.2) in a 60:40 (v/v) ratio, with a flow rate of 1.0 mL·min−1 and UV detection at 220 nm. The method was validated for linearity, sensitivity (LOD and LOQ), precision, robustness, and system suitability, all within acceptable limits for low-concentration analysis. Excellent linearity (r2 > 0.999) and precision (%RSD 0.3–4.4%) confirmed its reliability for stability assessment. The assay was performed at 100 µg·mL−1, where all validation parameters showed %RSD values ≤ 2%, demonstrating high precision and robustness. Forced degradation studies under acidic, basic, oxidative, photolytic, and thermal conditions revealed a major degradation product formed under acidic stress. This product was isolated and structurally characterized using LC–MS, 1H NMR, and 13C NMR, and is reported here for the first time. The proposed RP-HPLC method proved to be specific, precise, and reliable for the determination of bexagliflozin and its related impurities, making it suitable for routine stability testing, quality control, and pharmaceutical development applications.

The flow field evolution in the first turn of the spiral concentrator is decisive for the separation efficiency of solid particles. A laboratory-scale Φ300 mm spiral concentrator was employed as the study subject. The fluid phase was simulated using the RNG k-ε (Renormalization Group) turbulence model and the VOF (Volume of Fluid) multiphase model, while the particles were calculated with an Eulerian multi-fluid VOF model that incorporates the Bagnold effect. The influence of the cross-sectional curve equation on the evolution of flow field parameters in the first turn and on the separation behavior of hematite and quartz particles was systematically investigated. The results indicated that the evolution characteristics of fluid parameters, such as the depth of flow film, the tangential velocity of surface flow, the velocity of secondary circulation, and radial flux, were similar. All parameters were observed to undergo an initial decrease or increase, eventually stabilizing as the longitudinal travel progressed. A negative correlation was identified between the index of the cross-sectional curve equation and both the depth of flow film and the tangential velocity of surface flow in the inner half of the trough, whereas an inverse relationship was noted in the outer half. With an increase in the index of the cross-sectional curve equation, the outward circulation velocity in the initial stage and its radial flux in the outer zone were enhanced, while the fluctuations in the evolution of local fluid parameters were suppressed, with more active fluid radial migration observed at the indices of the cross-sectional curve equation of 2.5 and 3. As the flow field evolved, axial separation between hematite and quartz particles was progressively achieved by gravity due to their density difference. In the middle and inner-outer zones, the migration directions of hematite and quartz were observed to become opposite in the later stage of evolution, while the difference in their migration magnitudes was also found to be widened. With an increase in the index of the cross-sectional curve equation, the disparity in the axial separation and movement between hematite and quartz was enhanced, albeit with a diminishing rate of increase. The maximum separation efficiency between hematite and quartz particles was significantly improved with increased longitudinal travel, reaching over 60% by the end of the first turn; higher indices were determined to be more favorable for achieving this performance. Based on the previous research, the variation in separation indices in the third turn was investigated under both independent adjustment of the index of the cross-sectional curve equation and its combined adjustment with the downward bevel angle. Relatively high and stable separation performance was achieved with the indices of the cross-sectional curve equation of 2.5 and 3, where a maximum separation efficiency of 82.02% was obtained, thereby validating the high efficiency and suitability of the selected spiral concentrator profile. This research elucidated the decisive role of the flow field evolution through the first turn in particle separation behavior from the perspective of quantitative description of hydrodynamic parameters, providing beneficial references for the cross-sectional structure design of spirals and the prediction of the separation index of specific feed.

Active surface materials such as activated carbon are used in the removal of contaminants and dyes in effluents. The primary objective of this study was to convert starchy corncobs into valuable activated carbon, capable of efficiently adsorbing dyes, and to comprehensively analyze the resulting material’s physical and structural properties. To achieve this purpose, a 23 factorial design was employed to create optimized activated carbon for effective methylene blue dye adsorption. The factors considered were carbonization temperatures, carbonization times, and H3PO4 activating agent concentrations. This design yielded eight types of activated carbon, namely B-85%, D-85%, M-85%, L-85%, A-45%, S-45%, P-45% and X-45%, observing that the increase in temperature and carbonization time had negative effects on the adsorption capacity, while the increase in the percentage of activating agent had positive effects. The variant labeled as A-45% displayed the highest cationic methylene blue dye removal efficiency, boasting a remarkable adsorption capacity of 99.93%. This result almost reached the performance of commercial activated carbon, which exhibited a similar methylene blue dye removal efficiency (99.94%), while the removal efficiency of the anionic dye nigrosin was 95.24%. X-ray diffraction analysis of activated carbon A-45% indicated a slightly crystalline amorphous structure. Moreover, surface area analysis utilizing the BET method revealed that this material possessed a micromesoporous nature, mainly consisting of cylindrical micropores, resulting in an impressive surface area of 306,493 m2/g. FTIR analysis revealed the presence of functional groups, including O-H, C=C, C-O, C-X, and P=O, which create a highly polar surface that enhances the chemisorption of cationic molecules like methylene blue. These findings demonstrate the potential application of the synthesized activated carbon in industrial effluent treatment processes.

Chicken egg is included among the main components of the human diet as an important source of nutrients, such as proteins, lipids, vitamins, minerals and carotenoids. The latter are terpenoid pigments present in egg yolks, providing their color and playing a vital role because of their significant bioactivities. The carotenoid content of egg yolk varies considerably since it is strongly influenced by the respective laying hens’ farming and feeding procedures, and there is therefore a need to establish an efficient method for their assessment. The absence of such a method prompted us to develop a novel procedure consisting of the extraction, saponification and quantitative assessment of contained carotenoids. For this purpose, the optimal conditions for the extraction of carotenoids from egg yolks were defined, along with the optimal saponification conditions of carotenoids, with respect to reaction duration and pH influence on the extract’s contents of lutein and zeaxanthin. The carotenoid content of extracts was determined using a novel, developed herein LC-MS/MS method that allows the accurate, fast and simultaneous quantitation of the 11 most abundant carotenoids in egg yolks. The method accuracy and reliability were validated for six different parameters determined for each analyte. The novel procedure was applied for the assessment of the carotenoid content of ten egg yolks of diverse origin, indicating the bioactive carotenoids lutein and retinol as the most abundant, while lesser amounts of the remaining natural and synthetic carotenoids were found and there was no trace of fucoxanthin or astaxanthin molecules. The results herein revealed a variation in the carotenoid content of chicken eggs that depended on the diet and farming method of egg-laying hens.

Surfactants are chemical compounds present in a large number of products that people use on a daily basis, starting with detergents for washing clothes, dishes, personal hygiene products, etc. Some products also contain certain heavy metals. Their uses cause heavy contamination of wastewater that must be purified before discharge into receivers. Given that some types of surfactants are very persistent and heavy metals are non-biodegradable and toxic even in small concentrations, the purification process requires a complex approach and a combination of different methods. Bioremediation, as an environmentally acceptable and economically clean technology, has great potential. It is based on the use of indigenous microorganisms that have developed different mechanisms for breaking down and removing or detoxifying a large number of pollutants and are excellent candidates for bioremediation of wastewater. Bacteria can degrade surfactants as sole carbon sources and exhibit tolerance to various heavy metals. This paper summarizes the most significant results, highlighting the potential of bacteria for the biodegradation of surfactants and heavy metals, with the aim of drawing attention to their insufficient practical application in wastewater treatment. Bioreactors and microbial fuel cells are described as currently relevant strategies for bioremediation.

The exploit of an efficient method for uranium (U) extraction is crucial for the development of nuclear energy. In this study, an aminated lignin-based microsphere (AL-PEI/GMS) was synthesized and used as an adsorbent for the recovery of hexavalent uranium (U(VI)) from salt-lake brine. The effects of adsorbent dosage, initial solution pH value, interfering ions, adsorption time, and temperature on the U(VI) adsorption performance of AL-PEI/GMSs were systematically investigated. The results show that when the adsorbent dosage was 2 g/L, the temperature was 45 °C, and the pH was 8, the adsorption capacity of AL-PEI/GMS for U(VI) could reach 256.4 mg/g. In addition, after five cycles, a high U(VI) adsorption efficiency of over 90% could still be achieved. Furthermore, through a fixed-bed system, AL-PEI/GMS could rapidly adsorb U(VI) from actual salt-lake brine. Therefore, the prepared AL-PEI/GMS is a competitive alternative material compared with other adsorbents in terms of efficiently recovering U(VI) from actual salt-lake brine.

Rosmarinic acid (RA), a natural polyphenolic hydroxyl compound found from plants, exhibits many biological activities. This study reported an efficient purification method for RA from the water-soluble rosemary extract. By employing silica gel column chromatography combined with liquid–liquid extraction, the water-soluble extract of rosemary was refined to yield RA with a purity of 92.85 ± 3.18%. To further enhance the potential of RA as a natural preservative, the prepared RA was esterified to produce methyl rosmarinate (RA-me) and propyl rosmarinate (RA-pro). The antioxidant and antibacterial activities of RA and its derivatives were subsequently evaluated. The results indicated that RA and its esterified derivatives exhibited more pronounced antibacterial efficacy against the Gram-positive bacteria than Gram-negative bacteria. Moreover, the antibacterial activity of the ester derivatives was enhanced compared to that of RA. RA and RA-me exhibited comparable antioxidant activity, which was superior to that of RA-pro. In summary, this study established an effective purification strategy for RA, laying a foundation for developing better natural, non-toxic preservatives with antibacterial activity.