International Journal of Analytical Chemistry

There is growing demand for separation of ⁹⁰Y carrier free from ⁹⁰Sr coexisting to produce high purity ⁹⁰Y essential for radiopharmaceutical uses. Thus, in this context the sorption profiles of Y³⁺ and Sr²⁺ from aqueous solutions containing diethylenetriaminepenta acetic acid (DTPA), ethylenediaminetetra-acetic acid (EDTA), acetic acid, citric acid, or NaCl onto Chelex-100 (anion ion exchange) solid sorbent were critically studied for developing an efficient and low-cost methodology for selective separation of Y³⁺ from Sr²⁺ ions (1.0 × 10⁻⁵ M). Batch experiments displayed relative chemical extraction percentage (98 ± 5.4%) of Y³⁺ from aqueous acetic acid solution onto Chelex-100 (anion ion exchanger), whereas Sr²⁺ species showed no sorption. Hence, a selective separation of Y³⁺ from its parent ⁹⁰Sr²⁺ has been established based upon percolation of the aqueous solution of Y³⁺ and Sr²⁺ ions containing acetic acid at pH 1-2 through Chelex-100 sorbent packed column at a 2 mL min⁻¹ flow rate. Y³⁺ species were retained quantitatively while Sr²⁺ ions were not sorbed and passed through the sorbent packed column without extraction. The sorbed Y³⁺ species were then recovered from the sorbent packed column with HNO₃ (1.0 M) at a 1.0 mL min⁻¹ flow rate. A dual extraction mechanism comprising absorption associated to “weak-base anion exchanger” and “solvent extraction” of Y³⁺ as (YCl₆)³⁻ and an extra part for “surface adsorption” of Y³⁺ by the sorbent is proposed. The established method was validated by measuring the radiochemical (99.2 ± 2 1%), radionuclide purity and retardation factor ( = 10.0 ± 0.1 cm) of ⁹⁰Y³⁺ recovered in the eluate. Ultimately, the sorbent packed column also presented high stability for reusing 2-3 cycles without drop in its efficiency (±5%) towards Y³⁺ uptake and relative chemical recovery. A proposed flow sheet describing the analytical procedures for the separation of ⁹⁰Y³⁺ from ⁹⁰Sr²⁺ using chelating Chelex 100 (anion exchange) packed column is also included.

Traditional Chinese medicine (TCM) serves as a significant adjunct to chemical treatment for chronic diseases. For instance, the administration of Baitouweng decoction (BTWD) has proven effective in the treatment of ulcerative colitis. However, the limited understanding of its pharmacokinetics (PK) has impeded its widespread use. Chinese Bama miniature pigs possess anatomical and physiological similarities to the human body, making them a valuable model for investigating PK properties. Consequently, the identification of PK properties in Bama miniature pigs can provide valuable insights for guiding the clinical application of BTWD in humans. To facilitate this research, a rapid and sensitive UPLC-MS/MS method has been developed for the simultaneous quantification of eleven active ingredients of BTWD in plasma. Chromatographic separation was conducted using an Acquity UPLC HSS T3 C₁₈ column and a gradient mobile phase comprising acetonitrile and water (containing 0.1% acetic acid). The methodology was validated in accordance with the FDA Bioanalytical Method Validation Guidance for Industry. The lower limit of quantitation fell within the range of 0.60–2.01 ng/mL. Pharmacokinetic studies indicated that coptisine chloride, berberine, columbamine, phellodendrine, and obacunone exhibited low , while fraxetin, esculin, fraxin, and pulchinenoside were rapidly absorbed and eliminated from the plasma. These findings have implications for the development of effective components in BTWD and the adjustment of clinical dosage regimens.

Leontopodium leontopodioides (Willd.) Beauv. (L. leontopodioides.) has been used to treat lung diseases in traditional Chinese medicine (TCM). However, a systematic analysis of its chemical components has not been reported so far. In this study, UPLC-Q-Orbitrap MS and GC-MS were applied to investigate the chemical composition of the water extracts and essential oils of L. leontopodioides. UPLC-Q-Orbitrap MS adopts a heating electrospray ionization source, collecting primary and secondary mass spectrometry data in positive and negative ions, respectively, and uses Compound Discoverer 3.2 software to analyze the collected raw data. As a result, a total of 39 compounds were identified from their high-resolution mass spectra in both positive and negative ionization modes, including 13 flavonoids and their glycosides, 15 phenolic acids, 4 oligosaccharides and glycosides, 4 pentacyclic triterpenoids, and 3 other compounds. Among them, 18 chemical components have not been reported in L. leontopodioides. In the GC-MS section, two common organic solvents (n-hexane and diethyl ether) were used to extract essential oils, and the mass spectra were recorded at 70 eV (electron impact) and scanned in the range of 35∼450 m/z. Compounds were identified using NIST (version 2017), and the peak area normalization method was used to calculate their relative amounts. Finally, 17 components were identified in the volatile oil extracted with n-hexane, accounting for 80.38% of the total volatile oil, including monoterpenoids, phenylpropene, fatty acids, and aliphatic hydrocarbons. In the volatile oil extracted with diethyl ether, 16 components were identified, accounting for 73.50% of the total volatile oil, including phenylpropene, aliphatic hydrocarbons, monoterpenoids, fatty acids, and esters. This study was the first to conduct a comprehensive analysis of the chemical composition of the L. leontopodioides water extract and its essential oil, and a comprehensive chemical composition spectrum was constructed, to lay a foundation for its further pharmacodynamic material basis and quality evaluation.

The advanced and highly functional properties of Al₂O₃ and NiO nanoparticles promote the widespread use of metal oxides as remarkable electroactive materials for sensing and electrochemical applications. The proposed study describes a comparison of the sensitivity and selectivity of two modified wire membrane sensors enriched with Al₂O₃ and NiO nanoparticles with conventional wire membranes for the quantification of the antidiabetic drug metformin hydrochloride (MTF). The results show linear relationships of the enriched Al₂O₃ and NiO nanosensors over the concentration ranges 1.0 × 10⁻¹⁰–1.0 × 10⁻² mol L⁻¹ and 1.0 × 10⁻⁶–1.0 × 10⁻² M for both the modified sensors and the conventional coated wire membrane sensors. The regression equations were  = (52.1 ± 0.5) log (MTF) + 729 for enriched nanometallic oxides,  = (57.04 ± 0.4) log (MTF) + 890.66, and  = (58.27 ± 0.7) log (MTF) + 843.27 with correlation coefficients of 0.9991, 0.9997, and 0.9998 for the aforementioned sensors, respectively. The proposed method was fully validated with respect to the recommendations of the International Union of Pure and Applied Chemistry (IUPAC). The newly functionalized sensors have been successfully used for the determination of MTF in its commercial products.

Urine test strips for urinalysis are a common diagnostic tool with minimal costs and are used in various situations including homecare and hospitalization. The coloration scaled by the naked eye is simple, but it is suitable for semiquantitative analysis only. In this paper, a colorimetric assay is developed based on a smartphone digital camera and urine test strips. Assays of pH, albumin, glucose, and lipase activity were performed as a tool for the diagnosis of aciduria, alkaluria, glycosuria, proteinuria, and leukocyturia. The RGB color channels were analyzed in the colorimetric assay, and the assay exerted good sensitivity, and all the particular diagnoses proved to be reliable. The limits of detection for glucose (0.11 mmol/L), albumin (0.15 g/L), and lipase (2.50 U/μL) were low enough to cover the expected physiological concentration, and the range for pH was also satisfactory. The urine test strips with a camera as an output detector proved applicability to spiked urine samples, and the results were also well in comparison to the standard assays which confirms the practical relevance of the presented findings.

The combined prescriptions of nirmatrelvir/ritonavir and other drugs are limited due to potential drug-drug interactions, so therapeutic drug monitoring (TDM) becomes particularly important. In this study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established for determination of the nirmatrelvir/ritonavir in plasma of patients with COVID-19, providing technical and theoretical support for the TDM. Plasma samples were processed by protein precipitation using acetonitrile, and analytes were separated on an Agilent Poroshell 120 SB-C18 (2.1 × 75 mm, 2.7 μm) column at 35°C. Acetonitrile and 0.1% formic acid in water (52 : 48) were utilized as the mobile phases at a flow rate of 0.3 mL/min. In the multiple reaction monitoring (MRM) mode, nirmatrelvir and ritonavir were monitored using precursor/product ions: m/z 500.2/110.1 and 721.3/296.1, respectively, with selinexor as the internal standard. The linear range of both analytes was 2.0 ng/mL to 5000 ng/mL with good inter- and intraday precision and accuracy, and the recovery was 92.0%–107% for nirmatrelvir and 85.7%–106% for ritonavir. Finally, this method was successfully applied to monitor the exposure levels of nirmatrelvir/ritonavir in plasma samples from hemodialysis patients.