Chromatographia最新文献

In this study, an automated micro-solid-phase extraction (μSPE)–liquid chromatography–tandem mass spectrometric (LC–MS/MS) method was developed and validated to determine aripiprazole, dehydroaripiprazole, blonanserin, and N-desmethyl blonanserin in human urine. An instrument top sample preparation cartridge was implemented to enhance analyte sensitivity and mitigate the matrix effects from urine samples. LC–MS/MS analysis employed a multiple-reaction monitoring mode, with analyte separation achieved using a Capcell Pak C18 MGIII column (2.0 × 150 mm, 5 µm). The mobile phase comprised a 10 mM ammonium formate solution with 0.1% formic acid and acetonitrile. The calibration range for all analytes was 0.1–50 ng mL⁻¹, yielding correlation coefficients (r) of ≥ 0.9993 and a weighting factor of 1/x². The detection limits for all analytes were 0.03 ng mL⁻¹. Intra- and inter-day accuracy ranged from − 3.6 to 5.0% and − 4.0 to 3.3%, respectively, with precision values of ≤ 9.5% and ≤ 12.9%. This validated method was successfully applied to 107 forensic urine samples. Urinary creatinine normalization was used to adjust analyte concentrations in urine. Normalized concentrations of aripiprazole, dehydroaripiprazole, blonanserin, and N-desethyl blonanserin were detected at 0.1–185.2 (n = 86), 0.2–295.5 (n = 91), 0.1–0.7 (n = 7), and 0.2–1.6 (n = 12) ng mg⁻¹ creatinine, respectively.

The study aimed to optimize and validate a robust green HPLC method for quantifying and separating process-related impurities of ivosidenib. Further, the study intended to characterize the degradation products (DPs) of ivosidenib formed under various stress conditions. Among the columns tested, the Zorbax Eclipse Plus C18 column (250 mm) column was proved to be the best for the resolution of ivosidenib and its impurities using ethanol and 0.1% aqueous formic acid in 45:55 (v/v) at 0.8 mL/min flow rate and 245 nm detector wavelength. This method produces a clear resolution of ivosidenib and its impurities with no interference from blank samples providing the specificity and robustness of the method. The technique demonstrated linearity (r² ≥ 0.9994), precision (intraday and interday % RSD < 2), accuracy (recovery: 98–102%), ruggedness, robustness, and stability under varied conditions. Forced degradation studies revealed distinct DPs under acidic, UV, and oxidative stress conditions, and these DPs were characterized using LC–MS techniques. The toxicity prediction indicated neurotoxicity and respiratory toxicity for all DPs with specific compounds exhibiting hepatotoxicity, nephrotoxicity, or immunotoxicity. The environmental impact of the proposed method was assessed through AGREE and GAPI tools and the technique exhibits high compliance with green analytical chemistry principles. This result highlights method reliability, efficiency, and eco-friendliness to pharmaceutical safety and environmental sustainability.

Two-dimensional high performance liquid chromatography (2D-LC) offers unique insights into the polyolefins’ chemical composition and how that relates to their molar mass distribution. Moreover, the numerical format of the sample’s 2D-LC data (i.e., the J x K matrix of molar mass (MM) and comonomer (CM) content, respectively) allows for further correlations between the sample’s structural parameters and its physical properties via statistical multi-way methods. However, before applying these advanced methods to multi-sample data sets, we first determined the extent of variability and quantitation limits of these structural parameters for individual samples. In this current work we evaluated the 2D-LC MM data (measured on one SEC column) for a number of metallocene-catalyzed polyethylene resins and compared the results to those acquired on a typical three column SEC unit.

Our initial assessment shows that the presence of 1-decanol interferes with accurate MM measurements when using typical calibration methods that employ MHS constants. However, accurate MM data were obtained by using a single sample integral calibration (SSIC) method, where the sample’s MMD measured on a three-column SEC unit is used to calibrate the 2D-LC SEC data. The resulting MM values were within the expected error and consistent with published data. Additionally, the resulting MMD profiles, coupled with the known short-chain branching content for the samples, gave the expected crystallinity properties as measured by DSC and estimated densities.

Immunosuppressants and anticonvulsant drugs are routinely quantified using liquid chromatography–tandem mass spectrometry (LC–MS/MS) in whole blood and serum, respectively, which necessitates frequent phlebotomy visits for patients. Alternatively, dried blood spots (DBS) measurements have the potential to reduce the cost of sample collection and shipping, while simultaneously enabling convenient at-home collection for patients. We evaluated Transcend™ DBSA–TLX-1–MS/MS System through method development and analytical validation for measurements of immunosuppressants (tacrolimus, sirolimus and everolimus) and anticonvulsants (levetiracetam and lamotrigine) in DBS. Given the relatively low analytical measurement interval (AMI) for these immunosuppressants, sufficient sensitivity is imperative, and the desired lower limit of quantitation (LLOQ) of 1 ng/mL was achieved, with an interday %CV less than 10% at the LLOQ. Conversely, the comparatively high AMI for the anticonvulsant drugs necessitated careful optimization to avoid saturation and minimize imprecision. For all analytes, carryover was minimal, and linearity and accuracy using spiked samples indicated adequate performance based on the regression comparisons. Therefore, our proof-of-concept study suggests that the DBSA–TLX-1–MS/MS has the potential to provide exceptional analytical performance, which will facilitate future clinical validations while minimizing labor required to perform DBS measurements.

When certain amine salts are subjected directly to gas chromatography (i.e., without prior derivatization or deprotonation) even when highly pure two or more peaks are observed, only one of which is due to elution of the amine freebase. These unexpected results are confusing to analysts and if inexplicable results such as these are presented as evidence in a court of law they erode confidence in forensic analysis. There is little discussion in the literature regarding the origins of one of the unexpected ‘ghost’ peaks. This article indicates that the particular ‘ghost’ peak under discussion is not a ghost at all, but a peak due to the analyte itself—it arises as a result of elution of intact amine salt or carry-over of a salt from a previous injection. Elution of HI or HBr amine salts using gas chromatography—mass spectrometry can readily be confirmed by searching for the presence of halide⁺ and hydrohalide⁺ ions, but confirmation of HCl salts requires the mass spectrometer’s scan range to commence at low m/z in order to avert analytical confusion. Certain amine salts, such as drugs and explosives, are very important in forensic chemistry and the development of methodology based upon gas chromatography for the analysis of these compounds in their intact salt forms (i.e., where the cation and anion pairing information is not lost) would be a valuable contribution to the field. Other fields of analytical chemistry, such as environmental monitoring and analysis of food and industrial products may also benefit from the development of a GC method for the analysis of intact amine salts. The results presented here suggest that further development of gas chromatography for the analysis of intact amine salts is warranted.

This study presents an optimized method for determining major anions (chloride, sulfate, phosphate, citrate, and lactate) in human serum using capillary zone electrophoresis (CZE) with indirect photometric detection. A comparative analysis was conducted to evaluate the effectiveness of an electroosmotic flow (EOF) modifier (cetyltrimethylammonium hydroxide—CTAOH) and an ion-pairing reagent (tetrabutylammonium hydroxide—TBAOH). The optimal electrolyte composition (10 mM chromate, 16 mM DEA, 0.5 mM CTAOH) was determined, ensuring high separation quality and detection sensitivity. An improved sample preparation method, involving protein precipitation with acetonitrile, was implemented. Achieved limits of detection were 6 mg/L for sulfate, 12 mg/L for phosphate, 10 mg/L for citrate, and 16 mg/L for lactate. The method’s validation characteristics (spike-recovery of 90–111%, relative standard deviation (RSD) ≤ 10%) demonstrate high accuracy and reproducibility.

Omeprazole (OMP), a member of proton pump inhibitors class, is widely used in the treatment of dyspepsia and peptic ulcer disease, etc. A simple, robust, and stability-indicating reverse phase high performance liquid chromatography (RP-HPLC) method has been developed and validated for determination of OMP and its related substances. The analytes were separated on a short, fused core Halo octyl (C8) column (50 mm × 2.1 mm i.d., 2.7 µm particle size) using a gradient elution at a column temperature of 25 °C. Omeprazole and its related substances were monitored by UV detection at 280 nm. Mobile phase A (MPA) of the method is 10 mM ammonium acetate (NH₄OAc) in H₂O and mobile phase B (MPB) is MeOH/IPA (95/5). The total run time of the new method is 33 min. The new HPLC method has a significantly higher degree of selectivity and efficiency in separating OMP related compounds compared with the current compendial HPLC methods for OMP drug substance outlined in the United States and European Pharmacopeia monographs.

Introduction

A common selective serotonin reuptake inhibitor used to treat depression and obsessive–compulsive disorder is fluvoxamine maleate.

Objective

The goal of this study was to develop and validate a HPTLC method for the analysis of fluvoxamine maleate in pharmaceutical dosage forms, utilizing a risk-based quality by design approach.

Methods

HPTLC method was optimized with a mobile phase composed of toluene: ethyl acetate: methanol: triethylamine in a ratio of 1: 5: 4: 0.1 (v/v/v/v). UV detection was performed at 257 nm. Studies on forced degradation were carried out in a variety of stress environments, including as thermal, oxidative, hydrolytic, alkaline, acidic, and photolytic conditions, to assess stability of fluvoxamine maleate. The degradation products were characterized using high-resolution mass spectrometry to identify potential impurities and degradation pathways.

Results

The developed method demonstrated excellent linearity over a concentration range of 100 to 600 ng/band, with a correlation coefficient of 0.9994 and the LOD and LOQ values were found to be 15.36 ng/band and 46.55 ng/band. The method was validated in accordance with ICH Q2(R1) guidelines, confirming its specificity, linearity, precision, accuracy, and robustness. The green chemistry aspects of the method were evaluated using Analytical Greenness Metric Approach and Software and Green Analytical Procedure Index, which highlighted the method’s eco-friendly characteristics. Additionally, the Blue Applicability Grade Index tool was used to assess the method’s practicality and suitability for routine pharmaceutical analysis, confirming its application in real-world settings.

Conclusion

The validated HPTLC method for analyzing fluvoxamine maleate in tablet dosage forms was robust, reliable, and accurate. It effectively identified and characterized degradation products, ensuring the consistent quality and safety of pharmaceutical products. The method offers a sustainable and efficient alternative for quality control in the pharmaceutical industry, combining rigorous validation with environmentally conscious practices.

Graphical Abstract

Choerospondias axillaris (C. axillaris), recognized as an effective herbal remedy for coronary heart disease (CHD), has been clinically utilized. Although the angiotensin-converting enzyme (ACE) has been extensively investigated as a pertinent target for CHD treatment, there is currently limited research on screening potential ACE inhibitors from C. axillaris. To advance the broader utilization of C. axillaris in coronary heart disease treatment, the target active components of ACE in C. axillaris were analyzed through the integration of magnetic-targeted fishing technology with functionalized magnetic nanospheres. Magnetic nanospheres functionalized with GO@Fe₃O₄@SiO₂-ACE (SMGO-ACE) were characterized using a vibrating sample magnetometer (VSM), scanning electron microscopy (SEM), and transmission electron microscope (TEM). The specific binding of lisinopril with the angiotensin-converting enzyme was employed to optimize the performance of the synthesized material and the relevant conditions during targeted fishing. Subsequently, five active ingredients were identified as (2R,3S)-Dihydrodehydroconiferyl alcohol, isovanillin, quinic acid, chrysin, and isorhamnetin. This study provides a precedent for the targeted extraction and separation of active ingredients in complex mixtures.

Circulating tumor cells (CTCs) and blood plasma both work as biomarkers for the initial detection and diagnosis of metastatic cancers. Nowadays, with the development of microscale devices, for the separation of CTCs and blood plasma from normal cells, one of the most effective techniques is inertial focusing using microfluidic chips. The present research work reported a single inlet and single loop-based microfluidic chip for simultaneous separation of PC3 (prostate cancer) CTCs and blood plasma from normal blood cells using the inertial focusing approach. Two different sized PC3 CTCs and different inlet flow velocities corresponding to different Reynolds numbers are explored to accomplish optimum separation performance of the chip. Three-dimensional numerical simulations were executed with COMSOL Multiphysics 5.4 software and finite element method analysis. It has been confirmed that 100 % separation purity and cell recovery were achieved for both 17 µm and 20 µm PC3 CTCs at the Reynolds number of 67 and 65.67, respectively. The microfluidic chip also achieved a maximum plasma recovery of 54.87 % with 100 % purity.