International Journal of Analytical Chemistry最新文献

Piracetam (PRM) is a nootropic commonly used to improve cognitive function, memory, and learning ability. This method introduces a new spectrofluorimetric strategy for the identification of PRM, using metal oxide nanomaterials from Shilajit extract in a micellar medium. The technique is based on a unique fluorescent platform of aluminum oxide and nickel oxide nanoparticles (NPs) combined with sodium dodecyl sulfate (SDS). The metal oxide NPs were prepared by an environmentally friendly synthesis approach, using Shilajit extract as a dual-function agent for reduction and stabilization. Their morphology, size, and structural properties were comprehensively analyzed using a range of spectroscopic and microscopic methods. The innovative technique utilizes the unique fluorescence properties of alumina and NiO NPs in the presence of SDS to detect PRM with remarkable sensitivity and selectivity. This method enables high-precision measurements over a wide calibration range of 0.5-10 and 0.2-14 μg/mL for the two metal oxides, respectively. With PRM recoveries of 99.07% ± 0.65% and 99.60% ± 0.37%, the method has excellent accuracy and reliability. Medium precision was used to ensure that the method meets stringent precision standards. In addition, the environmentally friendly approach of using Shilajit extract for the sustainable synthesis of metal oxides reduces the impact on the environment while maintaining excellent analytical performance, as confirmed by an environmental impact assessment.

Narcotic scent mimics, which are chemicals that emit a perceivable scent similar to that of the illicit drug but do not possess the health and addiction risks of the drug, have applications ranging from canine training in law enforcement agencies to antinarcotic public education. However, low-cost and easily accessible formulation and delivery systems for narcotic scent mimics have thus far been lacking. In this work, we assess the potential of synthetic (metal-organic framework, MOF) and natural (cotton) materials as carrier and delivery agents for pseudoscent chemicals mimicking cocaine and methamphetamine. Through liquid chromatography-based analysis, both materials demonstrate capabilities to act as inert absorbents for the scent mimics, with cotton being the more effective material. Cotton material provides a safe, durable and inexpensive medium for pseudoscent storage and release. The pseudoscent delivery systems are easy to formulate, store and distribute, thus enabling widespread use for both specialised training and public educational purposes.

Pakistan has around 20,000 brick kilns, constituting 3% of global brick production. Consequently, air pollution and air quality indicators have significantly deteriorated. In this study, we examined the effect of different fuel types, such as coal, coal + wheat straw, and coal + rice straw, on stack emissions from FCBTK kilns and Zigzag kilns in Faisalabad, Pakistan. Standard protocols for measuring stack emissions, including smoke opacity, SO₂, and CO, were used. The results were compared with Pakistan's Punjab Environmental Quality Standards (PEQS). Specifically, in Zigzag kilns, blended fuels reduced CO emissions to approximately 123.7 mg/Nm³ with wheat straw and 162.2 mg/Nm³ with rice straw. In contrast, FCBTKs showed CO emission reductions of 233.17 mg/Nm³ with wheat straw and 341.07 mg/Nm³ with rice straw. For SO₂, Zigzag kilns achieved reductions of 412.7 mg/Nm³ with wheat straw and 352.4 mg/Nm³ with rice straw, while FCBTKs reduced emissions by 564.9 and 481.7 mg/Nm³, respectively. Smoke opacity in Zigzag kilns improved by 4.6 percentage points with rice straw and 2.3 with wheat straw, whereas in FCBTKs, the improvement was 41.4 and 20.3 percentage points, respectively. Statistical comparisons using Pearson's correlation and linear regression analysis further indicate that biomass additives combined with coal are more effective as fuels in the brick kiln industry. One-way ANOVA and Kruskal-Wallis tests, along with post hoc analysis, confirmed significant differences among fuel groups (p < 0.001), demonstrating strong relationships between fuel composition and emission levels. These additives significantly reduce air pollution and improve community health by lowering emissions of smoke opacity, SO₂, and CO. According to the results, blending agricultural residues with coal enhances emission performance, with Zigzag kilns showing the most significant reductions.

Dasatinib, a therapy for chronic myeloid leukemia, suffers from poor bioavailability. Self-microemulsifying drug delivery systems (SMEDDSs) are used to improve its dissolution. This study aimed to develop and validate a novel reverse-phase high-performance liquid chromatography (RP-HPLC) method for quantifying dasatinib in SMEDDS formulations. The RP-HPLC method utilized a mobile phase of methanol and 0.1% trifluoroacetic acid (55:45, v/v) and identified a peak wavelength for dasatinib at 324 nm. SMEDDS formulations comprised Capryol 90, Transcutol HP, and Tween 40. The method was validated according to ICH guidelines, demonstrating excellent linearity (R ² = 0.9993), accuracy (recovery between 98% and 101%), and precision (relative standard deviation of 0.73%). It also showed stability and reliability with limits of detection and quantification of 0.17 and 0.50 µg/mL, respectively. This RP-HPLC method meets all validation criteria and provides a robust, cost-effective tool for analyzing dasatinib in SMEDDS formulations.

Aminophenazone, dipyrine, and chlorpheniramine maleate combined drug is used as antipyrine and analgesic. In this study, a rapid, robust, and straightforward high-performance liquid chromatographic (HPLC) technique was developed, optimized, and validated for simultaneous analysis of aminophenazone, dipyrine, and chlorpheniramine maleate taking into account decomposition of dipyrine. On a C18 (4.6 mm × 15 cm; 5 μm) Shim-pack column, aminophenazone, dipyrine, and chlorpheniramine maleate were successfully eluted by using mobile phase, comprising water: methanol: triethylamine: glacial acetic acid (70:28:1:1 v/v/v/v) at flow rate 1.0 mL/min and wavelength of 254 nm. About 5 mg/mL sodium sulfite in diluent and mobile phase was used to prevent the hydrolysis of dipyrine after several investigations. The validation parameters, including specificity, linearity, LOD/LOQ, precision, accuracy, robustness, and solution stability, were verified for performance of the method. In specificity study, there was not any interference with main peak. The constructed calibration curve was found to be linear in the concentration ranges of 0.1-1.0 (aminophenazone), 0.1-1.0 (dipyrine), 0.002-0.020 (chlorpheniramine maleate) mg/mL, respectively. The % recovery at different concentrations was within the (98.0-102.0) %. When the column temperature, the flow rate, wavelength, and mobile phase composition were changed, the absolute difference of the content at different modified conditions were within 2.0 (%RSD) of the original condition. The solution was stable upto 24 h in room temperature (benchtop), autosampler (15°C-25°C), and refrigerator (2-8 degree). This method was successfully employed for the analysis of aminopyrine, metamizole, and chlorpheniramine maleate in marketed products, and the results were satisfactory. The confirmed RP-HPLC-UV method may be a workable analytical approach on a routine analysis.

This study developed and comprehensively validated an optimized analytical method based on secondary thermal desorption-gas chromatography (STD-GC) for the simultaneous determination of eight key benzene homologs in ambient and indoor air of residential areas. Compared to solvent desorption and single-stage thermal desorption, STD demonstrates superior desorption efficiency, reduced matrix interference, fully automated rapid operation, complete analyte transfer, thereby eliminating analyte losses while enhancing analytical accuracy and sensitivity, and solvent-free ensuring friendly to human and the environment. Aiming at the characteristics of target compounds and complex environmental matrices (e.g., humidity, coexisting interferents), sampling parameters, thermal desorption conditions, and gas chromatographic separation conditions were systematically optimized, with particular emphasis on ensuring baseline separation of xylene isomers. The method demonstrated linearity over 10-1000 ng with correlation coefficients (R ²) > 0.992. The spiked recoveries of the method ranged between 90.5% and 117.3%, with relative standard deviations ranging between 0.8% and 9.2%, the detection limits ranged from 50 to 120 ng/m³, and the lower limits of quantitation ranged from 20 to 480 ng/m³. This study established a standardized and highly reliable analytical workflow, addressing the issues of parameter inconsistency and insufficient validation in existing methods when applied to paired residential-indoor air studies. Using this method, ambient and indoor air samples were synchronously collected and analyzed in residential areas. Results demonstrated significant correlations between indoor and outdoor concentrations of benzene homologs. This study also provides a methodological foundation and practical guidance for accurate assessment of residents' exposure to benzene homologs.

Sweat is an alternative biological fluid to plasma, urine, hair, and saliva, and it is promising for various pharmaceutical research types. Excessive sweating is one of the symptoms of cystic fibrosis, a hereditary disease. In this study, an easy, simple, applicable, and economical HPLC method was proposed for sweat analysis of the lumacaftor/ivacaftor combination used in the treatment of the disease. The solvent for the method was selected using the Green Solvent Selection Tool (GSST). The mobile phase was gradient elution mode and contained a mixture of 0.1% formic acid in acetonitrile (v/v) and 0.1% formic acid in water (v/v). Analytes were detected at a wavelength of 220 nm. LOD values for LUMA and IVA are 3.16 and 0.92 μg/mL, respectively. The linearity range was 60-150 μg/mL for both analytes, and matrix-matched calibration was performed. The greenness was evaluated with AGREE and ComplexGAPI, the whiteness with the red-green-blue 12 (RGB 12) algorithm, and the blueness with the Blue Applicability Degree Index (BAGI). The AGREE score of the method was calculated as 0.72, the BAGI score as 87.5, and the RGB 12 algorithm as 88.3. As a result, the method was presented to researchers as a sustainable, green, and efficient method.

This study centered on creating and validating a UPLC-MS/MS assay that is both reliable and simple, making it suitable for measuring peiminine levels in the plasma of beagle dogs. The established method was then employed with the ultimate goal of elucidating the pharmacokinetic behavior of the compound. The Acquity UPLC BEH C18 chromatographic column was used for separating peiminine and camptothecin (internal standard, ISTD). A binary mobile phase consisting of acetonitrile and 0.1% formic acid in water was used for gradient elution at 0.4 mL/min. In the multireaction monitoring mode, peiminine and a triple quadrupole mass spectrometer with an electrospray ionization source were utilized to monitor peiminine and the ISTD, and detection was performed by monitoring the following transitions: m/z 430.28 ⟶ 412.25 for peiminine and m/z 349.03 ⟶ 305.09 for the ISTD. Results indicated that the accuracy was around 100%, with both interday precision and intraday (RSD) being less than 10.37%. Additionally, a linear response for peiminine was validated over the range of 1-200 ng/mL, with the LLOQ established at 1 ng/mL. In summary, this study perfectly combined the ultrahigh chromatographic separation ability with the ultrahigh sensitivity, selectivity, and structural analysis ability of mass spectrometry, achieving rapid (2 min), accurate, and ultrasensitive (LLOQ 1 ng/mL) analysis of peiminine in samples. Using the developed method, the pharmacokinetic profile of peiminine was successfully characterized in beagle dogs following oral administration.

Natural gas (NG), primarily composed of methane, is colorless and odorless, thus necessitating odorization to enable leak detection and accident prevention. Precise monitoring of odorants is critical to meet safety standards while preventing excessive dosing. This study introduces a real-time gas chromatography system integrating gas chromatography and photoionization detection for the real-time, online odorant analysis in gas pipelines. This system effectively isolates tetrahydrothiophene (THT) and sulfur-free odorants from NG, enabling accurate concentration quantification. It achieves THT detection within 2∼150 mg/m³, with a relative standard deviation (RSD) of less than 1.5% and maximum deviation of less than 3 mg/m³. Additionally, this system exhibits good field applicability. When combined with a cloud-based warning platform, it can achieve monitoring, warning, and self-optimization of odorant concentration. This study demonstrates the reliability of this system for NG odorant monitoring, providing a robust solution for pipeline safety management and regulatory compliance, while offering a new approach for NG safety testing.

With the advancement of multiomics technologies and cohort study designs, integrative omics research is increasingly applied to human health and nutrition. However, optimal storage and preprocessing of labile biological samples, particularly feces, remain challenging. In this study, we systematically evaluated three normalization methods-wet weight, dry weight, and protein quantification-for quantitative metabolomic profiling of fecal samples, using 41 metabolites. Fresh fecal samples from three healthy individuals showed high reproducibility, with 24 metabolites exhibiting a coefficient of variation (CV) below 30 for both wet and dry weight normalization. Fecal samples from 20 obese patients collected using the OMNIgene·GUT kit demonstrated improved reproducibility with wet weight normalization (20 metabolites, CV < 30) and protein quantification normalization (19 metabolites, CV < 30), whereas dry weight normalization yielded no metabolites meeting the CV < 30 criterion. Direct analysis of the kit solution without a drying step further enhanced chromatographic clarity, highlighting practical considerations for large-scale studies. Overall, wet weight normalization consistently minimized variation across sample types, providing a robust and standardized framework for fecal metabolite profiling. These findings demonstrate that the OMNIgene·GUT kit is compatible with broad-spectrum metabolomic analyses and support its integration into multiomics workflows. By establishing reproducible normalization protocols, this study provides the foundation for accurate, comparable, and scalable fecal metabolomics in both clinical and nutritional research settings.