Chromatographia最新文献

We developed a rapid and user-friendly method to detect bioactive terpenes in different Cannabis flower samples based on gas chromatography-mass spectrometry (GC–MS). We validated the method in terms of linearity, repeatability, detection and quantitation limits and recovery. We quantitatively determine the amounts of six terpenes in seven Cannabis samples.

Preservatives can be used in natural and organic cosmetics to prevent quality deterioration during distribution and use, but the ingredients permitted are limited in the Republic of Korea. A method of simultaneous analysis was developed to monitor natural and organic cosmetics distributed online for the presence of 15 illegally used preservatives. Considering the complexities of the cosmetic matrices, an optimized sample preparation method is essential. Therefore, we developed the optimal purification method by comparing three preparation methods: QuEChERS, high-speed centrifugation, and solid-phase extraction (SPE). The SPE method, which exhibited the most favorable results in matrix reduction, was employed. To establish the SPE-ultra-high-performance liquid chromatography-diode array detection method, factors such as the mobile phase and column were optimized. The optimal separation of the 15 preservatives was observed under the following conditions: mobile phase A comprising 0.1% phosphoric acid in water with 0.5 mM sodium hexanesulfonate and a C₈ column (1.7 μm, 2.1 × 150 mm) as the stationary phase. The linear correlation coefficients were > 0.9998, and the limits of detection and quantitation ranged from 0.05 to 0.67 and 0.15 to 2.02 μg mL⁻¹, respectively. Using the established analytical method, illegally used preservatives were detected in products claimed to be natural and organic cosmetics sold on the market, and these findings were subsequently verified using liquid chromatography-tandem mass spectrometry. Six out of 47 samples contained phenoxyethanol and parabens. Therefore, this method will help manage the addition of illegal preservatives to natural and organic cosmetics.

Afoxolaner, a novel insecticidal and acaricidal drug substance from the isoxazoline family, is efficacious against various parasites among companion animals. In general, afoxolaner drug substance is quite stable in formulated and unformulated forms, when stored under International Council for Harmonization (ICH) guideline storage conditions. Exhaustive stress degradation studies of afoxolaner drug substance were conducted under various stress conditions to obtain an in-depth understanding of potential degradation pathways, including formation mechanisms of potential degradations products of this compound. Stressed degradation studies were carried out in the presence of various type/class of acid, base, and oxidation agents, including thermal and light irradiation. An investigational ultra-high-performance liquid chromatography (UHPLC) method was developed for the purpose of this study. The UHPLC method provided adequate separation of afoxolaner and its major degradation products that were generated in the exhaustively stressed samples. A total of five major degradation products (DPs) were formed under acidic, basic, photolytic, and oxidative stress conditions. Various analytical techniques such as high-resolution tandem mass spectrometry (HRMS/MS–MS) and nuclear magnetic resonance (NMR) were used to identify and propose the most probable chemical structures of the key unknown degradation products in the stressed degradation samples. Adequate amounts of two DPs, namely DP-1 and DP-3, were isolated and purified by semi-preparative high-performance liquid chromatography (HPLC) methods. Subsequently, these two DPs were examined in detail using both 1D and 2D NMR spectroscopy. From the proposed chemical structures of identified degradation products, most probable degradation pathways and formation mechanism is proposed.

In this work, in order to investigate retention and selectivity mechanism on hydrophilic interaction liquid chromatography (HILIC), one of the most common hydrophilic stationary phases, polyethylene glycols (PEG) of different molecular weights (200, 400, 800 and 2000 Dalton) were covalently bonded to porous silica spheres via isocyanate silane. The PEG stationary phase was then characterized in detail by infrared spectroscopy, scanning electron microscope, nitrogen adsorption–desorption isotherms, and thermogravimetric analysis, and the PEG bonding density was determined as 2.7, 2.3, 1.4, 0.26 μmol m⁻², respectively. The HILIC retention mechanism was systematically conducted by quantitative evaluation of the effect of partitioning and adsorption, hydrogen bonding and hydrophilicity, and temperature on the retention of nucleosides and nucleobases. It was found that the retention was highly relevant on the partitioning, hydrogen bonding between solutes and PEG, and strong electrostatic interactions (attractive/repulsive) between solutes and silica. To further assess the separation performance, three kinds of polar compounds (nucleosides and nucleobases, organic acids and β-blockers) were chosen as probe compounds. Among the four PEG stationary phases, it was found that the higher PEG ligand density generally resulted into more superior separation performance to these polar compounds, that is, PEG200-bonded stationary phase with highest ligand density of 2.7 μmol m⁻² generated better resolution. Furthermore, higher ligand bonding mass would increase the retention of nucleosides, nucleobases and organic acids except β-blockers. Generally, the HILIC stationary phase with continuous and dense hydrophilic layer is beneficial to the separation of polar analytes.

Graphical Abstract

A new accelerated oxidation-ion chromatography method has been proposed to determine the phosphorus content in biodiesel. The feasibility of the method was verified based on its linear correlation, detection limit, accuracy, and comparison with other methods. Further, the effects of interfering ions and accelerated oxidation time on the phosphorus content determination have been discussed. The results revealed a good linear correlation coefficient (r = 0.99996) over a PO₄³⁻ concentration range of 0.1–4.0 mg·L⁻¹. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.005 and 0.016, mg·L⁻¹, respectively. The intra-day accuracy (relative standard deviation (RSD), n = 5) ranged between 1.08–3.96%, while the inter-day accuracy (RSD, n = 15) was 1.66–6.67%, and the recovery rate was between 80.88% and 89.71%. The matrix elements in the biodiesel samples had no significant effect on the determination of phosphorus content. Under an oxidation temperature of 110 ℃ and ventilation rate of 10 L·h⁻¹, the optimum accelerated oxidation time of biodiesel was found to be 18 h. Compared with other methods, the proposed method exhibited a better linear range and the lowest LOD. Furthermore, the efficacy of the method for quantifying the content of phosphorus in biodiesel has been validated through actual sample analysis.

The quantification analysis of microplastics (MPs) in bottled water, purified tap water and branded table salt was executed by double-shot pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS), and the concentration was expressed as a mass concentration, which was more suitable for the data comparison. MPs including polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polypropylene (PP), polystyrene (PS) and polyethylene (PE) were separated by filtration with glass fiber filter membranes. After being folded, the whole glass filter membrane containing MPs was transferred into a pyrolysis cup directly to avoid the sample loss during transfer. The characteristic pyrolysates were used to identify and quantify PMMA, PET, PC, PP, PS and PE. The linear relationships were found between the polymer weight amount and peak areas of each characteristic pyrolysates with the correlation coefficients larger than 0.993. The intra-day precisions of the pyrolysates for peak areas were 0.56–18.94%, and the inter-day variability was 8.47–19.88%. The recovery values of the spiked standards were in a range of 81.5–114.5%. MPs in bottled water, purified tap water and branded table salt samples were successfully quantified by the proposed Py–GC/MS method. For four brands of bottled water samples, 0.088 μg/L PET was found in one sample. PP was detected in all purified tap water samples from five brands with the concentrations between 0.028 and 0.489 μg/L, and PE was detected in purified tap water samples from two brands with the concentrations between 0.194 and 1.26 μg/L. As for nine table salt samples, PP were found in a range of 4.00–182.80 μg/100 g salt in eight table salt samples. Due to the high content of MPs in purified tap water samples and large daily consumption, the estimated daily intake (EDI) of MPs from purified tap water was calculated. The estimated daily intakes (EDIs) for adults are 2.57 ng PP/kg/d and 4.17 ng PE/kg/d from purified tap water; the EDIs for children are 5.63 ng PP/kg/d and 9.11 ng PE/kg/d from purified tap water.

A novel, environment friendly high-performance liquid chromatography method for the determination of Ganciclovir in drug and formulations. Current HPLC methods often rely on acetonitrile, a solvent known to pose environmental and health hazards. Despite extensive literature review ganciclovir was estimated using only traditional HPLC solvents no studies were reported using ethanol. The developed method utilizes a simple mobile phase consisting of ethanol and acidic water (pH 3.0) at an optimized ratio of 80:20 v/v. Separation is achieved on a Zorbax eclipse plus C18 column (4.6 × 150 mm, 5 μm) with a flow rate of 1.0 mL/min. The proposed method demonstrates excellent linearity, and precision, assessed by (r² ≥ 0.999) and %RSD by below 2%, with recovery 98–102%. The method’s greenness was evaluated using established assessment tools such as AGREE, GAPI, and COMPLEX GAPI confirming the method’s adherence to 12 green analytical principles. The proposed method’s capability of separation from degradation products and no significant change of peak area and retention time was observed. This study explores the feasibility of substituting the acetonitrile with an eco-friendly greener alternative, ethanol recognized for its low toxicity and environmental impact.

Graphical Abstract

The primary objective of this study is to implicate the Quality by Design (QbD) principle to develop a simple and stability—indicating High Performance liquid Chromatography (HPLC) method for analysing and quantifying Eltrombopag olamine. Initially, a comprehensive risk assessment was conducted using an Ishikawa (fish-bone) diagram. Following this, an Analytical Target Profile (ATP) was established, with desired specification and Critical Analytical Attributes (CAAs) were identified to fulfil these requirements. Additionally, Critical Material Attributes (CMAs) and Critical Process Attributes (CPPs) were chosen, as they can influence the CAAs. Subsequently, a three-level factorial design was utilized to optimize the primary contributing factors both numerically and graphically. The validation study was performed according to International Council for Harmonisation (ICH) guidelines and forced degradation studies were performed under various stress conditions. Optimal chromatographic separation was done using a mobile phase comprising acetonitrile and water with 0.3% formic acid in both phases at a ratio of 80:20% v/v, with 1.2 mL/min flow rate and UV detection at 248 nm. The developed method exhibited high sensitivity and specificity, with a linear range of 10–70 µg/mL and a correlation coefficient (R2) of 0.9999. It demonstrated accuracy with % recovery ranging from 98–100% and the detection and quantification limits of 0.2443 µg/mL and 0.7403 µg/mL, respectively. The forced degradation studies indicated that the drug is vulnerable to all stress conditions. Overall, the developed method proves to be suitable for estimation of Eltrombopag olamine in its marketed formulation, with potential applicability for analysing it in other dosage form and various biological samples available.

Combining anticancer drugs and phytomolecules with anticancer activity has opened up new avenues for cancer treatment and could be a potent alternative to conventional cancer therapy. Quercetin (QUR) and Erlotinib (ERB) exhibit potential anticancer properties. However, both drugs manifest low oral bioavailability due to low aqueous solubility, and interestingly, there is not a single validated UHPLC-PDA method for quantifying QUR and ERB simultaneously. Thus, the current study aims to address pharmaceutical challenges by encapsulating the two drugs in liquid crystalline nanoparticles (LCNPs) and to develop and validate a sensitive, accurate analytical, and bioanalytical method, as per guidelines, to quantify QUR and ERB simultaneously in LCNPs. Effective chromatographic elution of QUR and ERB has been achieved using a C8 reversed-phase column with an isocratic mobile phase at a flow rate of 1 mL/min, and both drugs were detected at 252 nm wavelength. The retention time was 5.3 and 7.7 min for QUR and ERB, respectively, while LOQ was less than 0.5 µg/mL for both drugs, appropriate for monitoring therapeutic drugs in preclinical and clinical research settings. The validated method was successfully applied to estimate the %drug entrapment efficiency, %drug loading, and %drug release for the simultaneous analysis of QUR and ERB in the LCNPs. The technique investigated both drugs’ pharmacokinetic characteristics in Sprague–Dawley rats. The results were deemed reliable, and the validated method was found to be precise and accurate as per guidelines for the simultaneous estimation of QUR and ERB, which have applications in formulation development and bioanalytical studies.