Critical reviews in analytical chemistry最新文献

Ropinirole, an indole-based dopamine agonist with high affinity for D2, D3, and D4 receptors, is widely used for Parkinson's disease (PD) and restless legs syndrome (RLS) due to its neuroprotective effects and ability to mitigate levodopa-induced motor complications. Despite well-established clinical efficacy and pharmacokinetics characterized by rapid absorption, hepatic metabolism via CYP1A2, and predominant renal excretion - comprehensive analytical profiling remains incomplete, particularly in stability-indicating methods, forced degradation studies, and impurity characterization. This review systematically evaluates ropinirole's pharmacological properties, formulation strategies (immediate-release [IR] and extended-release [ER]), and marketed products. It critically analyzes analytical methodologies, including HPLC, UHPLC (guided by Analytical Quality by Design [AQbD]), HPTLC, UV spectrophotometry, and LC-MS/MS, focusing on sensitivity, specificity, robustness, and regulatory compliance. HPLC dominates routine quantification, while UHPLC and LC-MS/MS excel in impurity profiling and pharmacokinetic studies. However, inconsistent reporting of forced degradation and stability assessments reveals critical gaps that hinder regulatory compliance and quality assurance. The indole moiety's influence on therapeutic action and analytical behavior underscores the need for tailored, validated methods addressing stability and impurities. Recommendations include developing robust stability-indicating protocols, implementing controlled stress testing, employing orthogonal techniques, and ensuring mass balance verification using advanced detectors and hyphenated tools. This review bridges pharmacological and analytical perspectives, advocating for next-generation platforms to enhance method sensitivity, selectivity, and reproducibility. Adopting validated, stability-indicating approaches will strengthen regulatory acceptance and improve therapeutic monitoring and quality control (QC) for ropinirole formulations.

While mass spectrometry (MS) excels at identifying pesticides due to its high resolution, its accuracy for quantifying pesticide concentrations is problematic. This meta-analysis employed a representative random sample of publications; consequently, alternative samples might generate divergent observations. The criteria for selecting publications for the meta-analysis are comparability of technologies with each group of GC-MS/MS and LC-MS/MS, simultaneous analysis of multiple pesticides, and easy access to the data. Nevertheless, contemporary studies follow analogous analytical principles. The meta-analysis findings comprise a full re-calculation of reported data from 28 analyzed publications (14 GC-MS/MS, 14 LC-MS/MS) on pesticide quantification. Outliers were reported by only one publication. Analysis (using PoPC) revealed a critical bias-negative calibration slopes were systematically discarded, indicating researchers likely repeated calibrations until obtaining positive slopes. This invalidates the statistical validity of the methods. The ensuing quantifications were therefore postulated to be unreliable. The calibration slopes were too shallow, leading to extremely high relative uncertainties (often ∼100% or more). This makes reliable quantification impossible. A matrix-effect problem was disclosed; the massive uncertainties mean the reported "abundant matrix effects" cannot be reliably distinguished from the measurement error itself. Claims about matrix effects were made with high precision but low accuracy. Due to the methodological bias and resulting high uncertainty, the actual concentration of pesticides in these studies remains scientifically undetermined. Potential bias may lead to uncertain conclusions, and issues with statistical methods and reproducibility were noted, warranting future attention. Pre-concentrating pesticides could improve reliability, as the PoPC showed lower variability at higher concentrations.

Colorectal Cancer (CC) is recognized as the third most prevalent cancer worldwide and constitutes a major cause of cancer-related fatalities among both genders. Current diagnostic approaches for CC exhibit several notable limitations; they are frequently invasive, their accuracy may vary based on the operator and the patient, and they might lack sufficient precision. Raman Spectroscopy (RS) and Infrared (IR) spectroscopy have surfaced as promising alternatives owing to their potential as swift and noninvasive diagnostic modalities. Nevertheless, spectroscopic methods produce extensive and intricate datasets characterized by overlapping peaks and subtle differences, which complicates direct visual interpretation. This review is dedicated to examining the chemometric techniques utilized in RS and IR spectroscopy for the diagnosis and evaluation of CC. Throughout this paper, we explore the experimental applications of chemometrics in conjunction with RS and IR spectroscopy. Chemometric algorithms, when integrated with RS and IR spectroscopy, have demonstrated their efficacy as robust tools for the detection, classification, and analysis of various colorectal cancer matrices. Indeed, it has been shown how chemometrics can be effectively applied in a variety of CC analysis.

Silver-doped layered double hydroxides (Ag-LDHs) have gained prominence as a high-performing class of electroactive materials suited to advanced electrochemical sensors, exhibiting remarkable sensitivity, selectivity, and long-term stability in environmental, biomedical, and food analytical settings. Silver incorporation not only narrows the band gap of the LDH host but also endows the heterostructure with enhanced electrical conductivity, surface reactivity, and rapid redox cycling, clearly outpacing both pure and conventional-metal-doped LDH architectures. These hybrids utilize the inherent ion-exchange capacity and extensive surface area of LDHs, further enhanced by integration with functional materials such as carbon allotropes, metal oxides, and conductive polymers, leading to a synergistic improvement in electrocatalytic performance and mechanical resilience. Despite several studies on these composites, a comprehensive study that critically compares structural designs, synthesis methods, and functional performance in electrochemical sensing is absent. This article addresses that gap by providing a systematic, side-by-side comparison of contemporary Ag-LDH synthetic routes, surface-modification protocols, and sensing metrics. Application-centric evaluations encompass the quantification of pollutants in aqueous matrices, the diagnosis of disease-relevant biomarkers, and the deterrence of unsafe food items. Enduring barriers, including the scale-up of manufacture with consistent quality, stability over extended operational lifetimes, and the realization of cost-competitive fabrication, are rigorously appraised alongside prospective pathways, such as eco-conscious synthesis protocols, hybrid nanoscale architectures, and machine-learning-augmented ideation of sensor designs. Collectively, the compiled findings furnish a coherent roadmap for the translational maturation of Ag-LDH-based electrochemical sensing technologies that transcend proof-of-principle and advance toward the reliable point-of-care deployment beyond controlled laboratory environs.

Gallstones are crystalline bodies with a heterogeneous composition in relation to the type, mainly categorized as cholesterol, pigment, or mixed stones. Their physicochemical properties need to be identified to make appropriate diagnoses, establish effective treatments, and implement sound prevention measures. This review has gathered a comprehensive set of techniques applied to characterizing gallstones. Spectroscopic techniques including Fourier-transform infrared (FTIR), Raman, and Ultraviolet-visible spectroscopy (UV-Vis) spectroscopy provide crucial functional groups and molecular structures and identify organic constituents such as cholesterol, bilirubin, and calcium bilirubinate etc. Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) and Laser-Induced Breakdown Spectroscopy (LIBS) deliver surface-sensitive elemental information, in the case of TOF-SIMS especially, to trace metals such as Fe, Cu, Zn, as well as contaminants like Pb and Cd. The thermal techniques like Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) extract differences in cholesterol content and heat stability between the different categories of stone. Complementary methods like X-ray diffraction (XRD) and scanning electron microscopy (SEM) dissect mineral phases and surface topography. Differential elemental quantitation with inductively coupled plasma optical emission spectroscopy (ICP-OES) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) determines Ca, Mg, and Fe to be major contributors to the development of gallstones. This review highlights the diagnostic value of elemental signatures, crystalline morphology, and thermophysical transitions in determining gallstone ethology and composition and help us in dealing with pathogenesis, with multi technique combination providing the most comprehensive description. Finally, the integration of analytical methods provides a solid basis for clinical and research gallstone analysis.

The increasing popularity in recent years of oral smokeless products (OSPs) and heated tobacco products (HTPs) has raised significant public health and regulatory concerns. Although these products are often marketed as less harmful alternatives to traditional cigarettes, they differ considerably in both design and, more importantly, in their chemical composition. Notably, they contain potentially dangerous compounds such as tobacco-specific nitrosamines, flavorings, heavy metals, and nicotine, which can be addictive and harmful to human health at certain concentrations. This work provides an overview of the analytical techniques and methods used to analyze OSPs and HTPs, including the determination of moisture content and pH, the extraction of various compounds, the generation of HTP aerosol, and non-targeted analysis, as well as the quantification of extracted compounds using gas chromatography, liquid chromatography, and spectroscopy. Identifying and quantifying the chemical composition of OSPs and HTPs is essential for assessing their health impact and developing proper regulatory standards regarding these products.

The clinical and laboratory diagnosis of diseases caused by parasites - helminths and protozoa - presents several limitations. To solve these gaps, new technologies have been developed. Metabolomics is in the spotlight due to its potential for discovering biomarkers that can be useful in the clinical laboratory. In this systematic review, we evaluate the main biomarkers identified in parasitic infections by metabolomics and the perspectives for their use in the clinical laboratory. The search was conducted on PubMed, SciELO Brasil and LILACS-Bireme platforms with the combination of descriptors "metabolomics" and "parasites" or "helminth" or "protozoan". A total of 65 studies met our eligibility criteria. Plasmodium spp., Toxoplasma gondii and Schistosoma spp. were the most studied parasites. Experimental infections were more commonly performed, indicating that metabolomics is in the process of being standardized for its application in laboratory routine. Among all metabolites, amino acids were the most commonly observed in parasitic infections. In the context of metabolite detection, the majority of studies employed mass spectrometry (MS), whereas only a limited number utilized nuclear magnetic resonance (NMR) spectroscopy. The main advantage of employing metabolites in diagnostics is their early detectability, overcoming limitations imposed by the parasite's life cycle and excretion dynamics. We demonstrate the potential of metabolomics tools as alternatives to complement the conventional parasitological diagnosis.

Benzene (Bz), phenol (Phen), hydroquinone (HQ), and catechol (CAT) are volatile organic compounds (VOCs) (monoaromatic compounds) considered environmental contaminants as a consequence of human and industrial activities. Prolonged exposure affects human health, causing cancer and death. Researchers have developed and applied analytical methodologies in pretreatment samples and detection techniques to analyze these monoaromatic compounds at trace and ultra-trace concentration levels. The present study is focused on an in-depth review and comparative analysis of removal and extraction techniques, summarizing the sources (analytical matrix), interaction modes (analyte-sorbent) in extraction techniques, solid phase extraction (SPE), dispersive solid phase extraction (DSPE), magnetic solid phase extraction (MSPE), and microextraction techniques), and the determination methods (chromatographic and non-chromatographic) applied in the analysis of these monoaromatic compounds in complex matrices.

An essential excitatory neurotransmitter and metabolic intermediary, L-glutamate is vital for multiple physiological functions, such as memory, learning, and synaptic transmission. A variety of neurological and neurodegenerative conditions have been attributed to aberrant glutamate levels, emphasizing the significance of reliable and continual monitoring in biological systems. Despite their remarkable sensitivity, classical analytical techniques are sometimes compromised by intricate procedures, outrageous expenses, and constrained applicability for point-of-care applications. However, enzymatic electrochemical sensors exhibit higher selectivity; their high production costs and inconsistent functioning make them impractical for long-term use. Nonenzymatic electrochemical sensors, on the other hand, have become a viable alternative due to their superior stability, cost-effectiveness, and ease of manufacture. Recent advancements in nonenzymatic glutamate sensors are thoroughly investigated in this review, with a focus on innovative material strategies that enable enhanced sensitivity, selectivity, and detection limits over a wide concentration range. The aforementioned strategies comprise metal and metal oxide nanostructures, carbon-based platforms, and hybrid composites. It also explores substantial breakthroughs in sensor architecture, operation, and practical applications in intricate biological matrices. These enzyme-free systems' expanding prominence in contemporary biosensing technologies is illustrated by their promise in therapeutic diagnostics, neurochemical research, and point-of-care testing.