Simultaneous identification and determination of biogenic amines in Pueraria lobata by ultra-high performance liquid chromatography

Evaluation of in-house-built pipette-tip micro-solid-phase extraction devices for sample preparation in the analysis of amino compounds by liquid chromatography-tandem mass spectrometry

Amino compounds are of significant interest in dietary, clinical, and quality control fields. Efficient extraction is crucial for comprehensive metabolomics, especially for amino acids and biogenic amines, but traditional solid-phase extraction (SPE) methods are costly and require large solvent volumes. Miniaturized SPE techniques, like pipette-tip micro-solid-phase extraction (PT-µ-SPE), offer promising alternatives by improving throughput and reducing solvent and sorbent usage. This study presents PT-µ-SPE for the screening and quantification of amino compounds in bee products, particularly honey. The method involves derivatization with diethyl ethoxymethylenemalonate (DEEMM) and analysis using liquid chromatography-triple quadrupole mass spectrometry. Silica-based SCX sorbents were effective for a broad range of amino compounds, while WCX sorbents were better for aliphatic amines. The method's extraction efficiency was assessed across sample loading, washing, and elution solution, with recovery rates of 70 - 120% in oat bran, sea buckthorn leaves, and honey extracts. Matrix effects were observed for four amino compounds in honey. Limits of detection (LoD) and quantification (LoQ) ranged from 0.37 to 57 µg L⁻¹ and 1.13 to 174 µg L⁻¹, respectively. Covering 48 amino compounds under different PT-µ-SPE conditions, this method has been applied to several samples, demonstrating accuracy, environmental sustainability, cost-effectiveness, portability, and versatility in amino compound analysis.

Preparation and application of UPLC silica microsphere stationary phase:A review

In this review, microspheres for ultra-performance liquid chromatography (UPLC) were reviewed in accordance with the literature in recent years. As people's demands for chromatography are becoming more and more sophisticated, the preparation and application of UPLC stationary phases have become the focus of researchers in this field. This new analytical separation science not only maintains the practicality and principle of high-performance liquid chromatography (HPLC), but also improves the step function of chromatographic performance. The review presents the morphology of four types of sub-2 μm silica microspheres that have been used in UPLC, including non-porous silica microspheres (NPSMs), mesoporous silica microspheres (MPSMs), hollow silica microspheres (HSMs) and core-shell silica microspheres (CSSMs). The preparation, pore control and modification methods of different microspheres are introduced in the review, and then the applications of UPLC in drug analysis and separation, environmental monitoring, and separation of macromolecular proteins was presented. Finally, a brief overview of the existing challenges in the preparation of sub-2 μm microspheres, which required further research and development, was given.

Free Amino Acids and Biogenic Amines Profiling and Variation in Wild and Sub-Endemic Cardueae Species from Sardinia and Corse

The cardueae are a common species in the Mediterranean area where they grow spontaneously and are traditionally employed as food and for health purposes. In this work, five Cardueae, including two sub-endemic species (four Carduus and three Ptilostemon casabonae (L.) Greuter samples from different locations) were collected from Sardinia and the Corse islands. All the considered plants are characteristic of the area, in particular the sub-endemic species C. cephalanthus and P. casabonae. This work aims to obtain, for the first time, the amino compounds profile (primary metabolites) of these little-studied species to detect for any similarities and differences among the different samples using statistical analyses. A recently developed method was employed, where diethyl ethoxymethylenemalonate (DEEMM) derivatives are detected in a neutral loss scan mode using high performance liquid chromatography in tandem with a mass spectrometry technique. In total, 42 amino compounds were detected, of which 33 were fully identified and semi-quantified. Overall, the results show that DEEMM-derivatized amino compounds are qualitatively similar among the considered samples. Nonetheless, a discrimination at the genus level is possible. This work adds more information regarding the phytochemical composition regarding the primary metabolites of the considered samples, their discriminations and the search for compounds with potential health benefits.