Simstrevino0237

Z Iurium Wiki

Verze z 7. 11. 2024, 22:54, kterou vytvořil Simstrevino0237 (diskuse | příspěvky) (Založena nová stránka s textem „dard deviations (RSDs, n=6) were 2.1%-4.7% and 2.8%-4.2%. The derivatization method established in this study showed good reaction specificity. The method…“)
(rozdíl) ← Starší verze | zobrazit aktuální verzi (rozdíl) | Novější verze → (rozdíl)

dard deviations (RSDs, n=6) were 2.1%-4.7% and 2.8%-4.2%. The derivatization method established in this study showed good reaction specificity. The method was successfully applied in the analysis of samples obtained from the Organisation for the Prohibition of Chemical Weapons (OPCW). The method established in this study for the detection of ClCN showed high sensitivity and precision, and could aid in the analysis and detection of ClCN in the environment.To strengthen regulation for mitigating the risk posed by petroleum contaminants in soil, the Ministry of Ecology and Environment of the People's Republic of China has classified petroleum hydrocarbons as a key monitoring item for regulatory contamination monitoring. Petroleum is principally derived from petroleum and synthetic fuels, which contain an extremely high content of hydrocarbon compounds that have varied boiling points. These compounds are chemically classified primarily as saturated and aromatic. Aromatic hydrocarbons are typically highly alkylated monocyclic, bicyclic, and polycyclic, which are more toxic to human and animal life than saturated hydrocarbons. Because of the significant toxicological differences among the various hydrocarbons, it is difficult to accurately assess their environmental toxicity by only determining the total content of petroleum in soil. However, there are no analytical methods for the simultaneous determination of saturated hydrocarbons and aromatic hydrocarbons in sodemonstrated in this study, can be used for the simultaneous determination of saturated and aromatic hydrocarbons in soil. The source of hydrocarbon contamination can also be preliminarily identified by chromatographic analysis.Phenoxy acid herbicides are widely used because of their excellent efficiency and low cost. However, owing to their strong polarity and water solubility, these herbicides do not degrade easily in a water environment and persist for a long time in water bodies. These herbicides readily enter water bodies via surface runoff, infiltration, and other migration routes, thus affecting water quality safety. Therefore, it is of great significance to establish a sensitive and simple method for the quantitative analysis of phenoxy acid herbicides in environmental water. Ipatasertib Given the low concentration of such contaminants in environmental water, appropriate detection methods are important. Ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) has high sensitivity and accuracy, thus being well suited for the phenoxy acid herbicides analysis. Sample preparation techniques are also important for the extraction and enrichment of contaminants in environmental water. Dispersive solid phase extraction (DSPs the advantages of simplicity, rapidity, and sensitivity, and it is suitable for the detection of the seven phenoxy acid herbicides in environmental water.Domoic acid (DA) can poison or even be fatal to marine mammals, and poses a potential risk to human health via transmission through the food chain. The level of DA in seawater will affect the safety of seafood. Therefore, a powerful method for the detection of DA in seawater, especially in the coastal mariculture zone, is needed. In order to identify different concentration levels of DA in real seawater, in this study, a method was established for the determination of trace DA in seawater by SPE-LC-MS/MS. First, the LC-MS/MS instrument and sample pretreatment conditions were optimized. Subsequently, DA was separated on a 5 TC-C18 (2) analytical column (150 mm×4.6 mm, 5 μm), and multiple reaction monitoring (MRM) was conducted in the positive electrospray ionization mode. For off-line SPE, the HLB cartridge could enrich DA in seawater. The best enrichment of DA was obtained after adding 0.32 mL formic acid to an 80.0 mL seawater sample. Four on-line SPE columns from Agilent, namely, 5 TC-C18(2) (12.5 mm×4.6 mmine SPE, a 0.6 mL sample was injected for on-line SPE-LC-MS/MS. The DA in the spiked blank seawater sample showed a good linear relationship in the range of 0.3-50.0 ng/L (R2=0.9990). The LOD and LOQ were 0.1 and 0.3 ng/L, respectively. The recoveries of DA at low, medium, and high spiked levels in the blank seawater samples were all ≥69.2%, and the RSDs were ≤4.4%. The MEs of DA with both methods were 18.3% and 13.7%, respectively, indicating that the ME was mild enough to be negligible. In summary, the proposed method is simple, sensitive, robust, and powerful for the detection of DA in inshore and offshore seawater.The complexity of the soil matrix, as well as the wide spectrum and trace levels of antibiotic residues in soil, make highly sensitive instrumental methods, efficient purification and enrichment methods, and simultaneous determination of multiple antibiotics key and challenging aspects in the analysis of antibiotics in soil. In this study, a solid phase extraction-ultra-high performance liquid chromatography-tandem mass spectrometry (SPE-UHPLC-MS/MS) method was developed for the simultaneous determination of 30 antibiotics (grouped into seven categories sulfonamides, fluoroquinolones, tetracyclines, macrolides, β-lactams, amphenicols, and lincosamides) in soil samples. In the UHPLC-MS/MS experiment, florfenicol and chloramphenicol were analyzed in the negative ionization multiple-reaction monitoring (MRM) mode, and the other 28 target analytes were analyzed in the positive MRM mode. Sensitive MS conditions were realized by optimizing the instrumental parameters such as collision energy and declustering potentof trace levels of the 30 antibiotics in soil.To enrich data related to the interaction mechanism between microplastics and organic pollutants, in this study, 3-hydroxy-phenanthrene (3-OHP, C14H10O), a phenanthrene derivative, was selected as a representative pollutant, and polyvinyl chloride (PVC) microplastics were chosen as the research objects. We investigated the adsorption behavior of 3-OHP on PVC microplastics in aqueous solutions and explored the adsorption mechanism in detail. The PVC microplastics were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) spectroscopy. The standard curves of the ultraviolet (UV) absorption spectrum of the target pollutant were obtained using a UV spectrophotometer. The fitting coefficient values of all standard curves were higher than 0.99 (R2>0.99). To ensure the accuracy of the UV absorption spectrum, the pollutant concentration gradient was set according to the absorbance (Abs) values, which were higher than 0.438. The measured concentrations were calculated using a standard curve equation.

Autoři článku: Simstrevino0237 (Frazier Jefferson)