Analytical Methods最新文献

The increasing prevalence of HIV has made us rely on a fixed dose combination (FDC) of anti-retroviral agents including lamivudine (LVD), tenofovir disoproxil fumarate (TDF) and efavirenz (EFZ) to ensure better therapeutic outcomes. In this context, the present study aims to develop and optimize Analytical Quality by Design (AQbD) employing D-optimal and Box–Behnken designs to simultaneously estimate LVD, TDF, and EFZ in a FDC. The optimized mobile phase (pH 4.5) comprised 25% acetonitrile (ACN), 46% methanol, 25% buffer and 4% KOH (30% w/v). The method parameters optimized included a 0.62 ml min⁻¹ flow rate, 10.96 μl injection volume and 36.95 °C column temperature. Under these conditions, retention times (RTs) for LVD, TDF, and EFZ were 4.1 ± 0.2, 5.1 ± 0.3, and 8.6 ± 0.4 min, respectively with an acceptable tailing factor (TF) of 1.55 ± 0.02, 1.43 ± 0.02, and 1.69 ± 0.02 respectively. Forced degradation studies conducted employing the optimized method showed ≤10% peak degradation. The method demonstrated ≤2.00% RSD for the TF, theoretical plates (TP), peak area, robustness and intra/inter-day precision when validated as per ICH Q2 (R1), ICH-Q12 and ICH-Q14 guidelines. The accuracy was observed to be in the range of 99.35 ± 0.43 to 101.22 ± 0.24%, 99.72 ± 0.39 to 101.37 ± 0.23% and 99.64 ± 0.38 to 101.83 ± 0.41% for LVD, TDF, and EFZ respectively. In rabbit plasma, at the lowest spiked concentration (0.25 μg ml⁻¹) the recovery rates for LVD, TDF, and EFZ were 97.81%, 95.92% and 96.38%, confirming the sensitivity of the AQbD driven optimized HPLC method. The study successfully demonstrated the robustness and suitability of the AQbD based analytical method for possible clinical applications.

Sodium dodecyl sulfate (SDS) is widely used in numerous household products and pharmaceuticals due to its excellent water solubility, emulsification, foaming, and dispersing properties. However, the extensive use of SDS has made it a significant environmental pollutant, posing a great threat to aquatic ecosystems. Therefore, developing a rapid, efficient, and sensitive probe for detecting SDS in aqueous environments is crucial. In this study, we present a cationic imidazolium-conjugated perylene bisimide (PBI) compound, as an effective probe for detecting SDS in aqueous media. The probe exhibits a distinct color change from dark pink to light pink upon interaction with SDS, making it a simple yet powerful tool for naked-eye detection. Moreover, the strong electrostatic interaction between the positively charged PBI compound and the negatively charged sulfate group in SDS leads to the formation of closely packed molecular aggregates. This results in significant quenching of fluorescence emission, enabling the detection of SDS at micromolar concentrations. We further demonstrate the practical application of PBI compound for sensitive and selective fluorometric detection of SDS in home-care items and tap water samples. These findings highlight the potential of such compounds as versatile tools for both environmental monitoring and product safety applications involving sulfate-containing species.

Nerve agents are highly toxic compounds that are based on organophosphorus chemistry, and their use is banned by international treaties regarding chemical weapons. Among the various nerve agents, sarin is highly lethal and inhibits the neuronal transmission and signaling of acetylcholinesterase. This study reports a fluorescent probe, (E)-3-(((2-(1H-benzo[d]imidazole-2-yl)phenyl)imino)methyl)-2-methoxy-2H-chromen-4-ol (BPMC), that demonstrates exceptional efficiency in detecting diethylchlorophosphate (DCP), a sarin surrogate, in solution and vapor phases. The gradual addition of DCP to the probe solution leads to a turn-on photoluminescence transition from blue to cyan because of the extension of intramolecular charge transfer transition (ICT) and inhibition of the excited-state intramolecular proton transfer (ESIPT) process. The minimum levels of DCP for detection and quantification were determined to be 6.6 μM and 22 μM, respectively, in the presence of various analogous analytes. Additionally, a test kit made of strips of cellulose paper was successfully assembled for real-time application. Dip-stick and dip-vial-conical-flask analyses were demonstrated as effective tools for detecting and quantifying DCP in the vapor phase. Furthermore, a smartphone-based approach was executed for the practical application of BPMC, enabling immediate identification and quantification of DCP in actual danger scenarios. Thus, this work presents a new ratiometric fluorogenic probe for the detection of sarin surrogate with potential application in actual hazardous situations.

Dioxins rank among the most hazardous persistent organic pollutants, presenting a serious threat due to their long environmental lifespan and capacity for bioaccumulation. This comprehensive review delves into the historical, chemical, and toxicological aspects of dioxins, spotlighting significant incidents such as the Seveso disaster and the repercussions of Agent Orange. The review offers a thorough analysis of the sources of dioxin formation, encompassing natural occurrences like volcanic eruptions and wildfires, alongside man-made activities such as industrial combustion and waste incineration. It examines regional variations in dioxin contamination, revealing air concentrations that can range from less than 0.01 pg TEQ per m³ in remote regions to as high as 2 pg TEQ per m³ in urban environments. With global dioxin emissions estimated at around 97.0 kg TEQ per year, Asia and Africa emerge as the highest emitters among the continents, with the total global dioxin release approximately at 100.4 kg TEQ annually. Dioxin emissions per capita show stark contrasts across six continents, from 10.77 g TEQ per capita in Europe to a concerning 71.66 g TEQ per capita in Oceania. Furthermore, the concentration of dioxin compounds produced during combustion varies significantly, ranging from 15 to 555 ng m⁻². While dioxin emission regulations are intricate and differ globally, most nations require that concentrations remain below one ng m⁻². Globally, dioxin production is estimated at 17 226 kilograms annually, equating to about 287 kilograms in toxic equivalent (TEQ). This review critically examines the severe health implications of dioxins, which include carcinogenic effects, endocrine disruption, and immunotoxicity. Innovative remediation strategies, such as using nanomaterials for adsorption and advanced oxidation processes, are identified as promising pathways to tackle this pressing issue. Ultimately, this review underscores the necessity for enhanced monitoring systems and comprehensive policy frameworks to facilitate sustainable dioxin management and regulatory compliance. Taking decisive action is vital to protect public health and the environment from the ongoing threat posed by dioxins.

Traditional Chinese Medicine (TCM) holds significant potential as a natural source of medication, providing effective alternatives for preventing and treating thrombotic diseases. Although research on the anticoagulant activity of Agrimonia Pilosa Ledeb (Rosaceae, A. pilosa) has been paid attention to, the monomer component and its mechanism of action have not been studied deeply. Therefore, this study aimed to screen and identify the antithrombotic active components of A. pilosa by affinity ultrafiltration (AUF) combined with ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). The affinity between compounds and thrombin was studied through molecular docking, and the activity of thrombin inhibitors was evaluated from multiple dimensions by the zebrafish thrombus model, chromogenic substrate method, and coagulation factor test. Eleven ligands with potential antithrombotic activity were screened from A. pilosa. Among them, compounds hyperoside, quercitrin, afzelin, baicalin, quercetin, kaempferol, and 3-O-caffeoylquinic acid were shown to have antithrombotic activity. This study is the first to report that kaempferol-3-rhamno-glucoside, tiliroside, and taxifolin exhibit thrombin-inhibitory effects through both in vivo and in vitro experiments. The results of this study indicate that AUF-HPLC and UPLC-Q-TOF-MS can be used for high-throughput screening of active components from TCM, thus laying a groundwork for the discovery of thrombin inhibitors and promoting the research progress of antithrombotic drugs.

The field of electrochemical ammonia synthesis has made rapid advancements, attracting a large number of scientists to contribute to this area of research. Accurate detection of ammonia is crucial in this process for evaluating the efficiency and selectivity of electrocatalysts. In this study, we systematically investigate the indophenol blue method for ammonia detection, examining the effects of key factors such as solution pH, nitrate concentration, and metal ion concentration on measurement accuracy. Based on experimental optimization and mathematical algorithms, we propose an iterative refinement method supported by custom-developed code. This method automates the generation and adjustment of calibration curves, reduces measurement errors, and enhances detection precision, offering a valuable framework for the quantitative detection of ammonia and other small molecules in electrochemical synthesis.

Correction for ‘A comparative review on the mitigation of metronidazole residues in aqueous media using various physico-chemical technologies’ by Moosa Es'haghi et al., Anal. Methods, 2024, 16, 7294–7310, https://doi.org/10.1039/D4AY01502A.

As an essential microenvironmental parameter, viscosity controls the diffusion of molecular species in cells to some extent during processes such as signaling, enzyme catalysis and biomolecular interactions. However, abnormal viscosity can lead to metabolic disorders and disease generation. Therefore, designing viscosity fluorescent probes for detecting viscosity changes in organisms is of great application value. Herein, a viscosity fluorescent probe (QM-C2) with aggregation-induced emission (AIE) effect was synthesized using quinoline-malononitrile with AIE properties as the electron acceptor and phenylcarbazole as the electron donor. Since the probe QM-C2 had a D–π–A structure, the phenylcarbazole moiety rotated freely in comparison to the quinoline-malononitrile moiety when it was in low-viscosity media, leading to a rapid energy depletion through a non-radiative transition process, which resulted in a weaker fluorescence. In contrast, the rotation of the molecular rotor was inhibited in high-viscosity media and the energy depletion of the non-radiative pathway was reduced, which resulted in an enhanced fluorescence. In addition, it was observed that common cationic, anionic and reactive oxygen species in the environment and in living organisms do not significantly interfere with the probe QM-C2, and it works effectively under a wide range of pH (pH = 4–10). Notably, the probe QM-C2 successfully monitored the viscosity changes induced by lipopolysaccharide, monensin and nystatin in zebrafish and nude mice.

Modern research in nutrition science is transitioning from classical methodologies to advanced analytical strategies, in which Raman spectroscopy plays a crucial role. Raman spectroscopy and its derived techniques are gaining recognition in nutrition science for their features, such as high-speed, non-destructive analysis, label-free multiple detection and high sensitivity. Raman-enhancing techniques have further improved the sensitivity of Raman spectroscopy and widely extended its detection and imaging applications in nutrient analysis, as well as in ancillary tasks for nutrition research, such as nutrient status evaluation, nutrient interaction and metabolism studies. Further development of Raman-based analytical approaches lies in the improvement of instruments with higher precision, as well as the incorporation of other analytical techniques and advanced data analysis tools. This paper provides a comprehensive review of the application of nanoscience and nanotechnology, with a specific focus on Raman technology, in the field of food and nutrition science research. Instead of delving into the quantitative or qualitative detection capabilities of Raman technology, we highlight the remarkable food analysis and nutrition research methods established by this technology. Generally, this review introduces the characteristics and applications of Raman technology in nutrition analysis and discusses the limitations and future prospects of Raman spectroscopy for nutrition monitoring.

Triterpenoids are known for their promising biological activities, and there is a growing focus on green extraction methods for these compounds. In this study, ultrasound-assisted deep eutectic solvents were employed to extract triterpenoids from persimmon leaves, with choline chloride–lactic acid identified as an effective green solvent. The extraction conditions were carefully optimized using response surface methodology, resulting in an extraction efficiency of 12.41%, which is 1.54 times higher than that achieved with conventional organic solvents such as methanol. The triterpenoids were then successfully recovered using a solid–liquid extraction method based on AB-8 macroporous resins, achieving a 94.01% recovery rate with a final product triterpenoid content of 81.87%. These findings provide a strong foundation for the sustainable extraction of triterpenoids and other valuable compounds from biomass.