A novel poly (NMA-co-DEA-co-EDMA) monolithic column as a sorbent for online solid-phase extraction and its application in the determination of β-sitosterol in plant oil samples

Phytosterols in Plant-Derived Foods: Recent Updates in Extraction and Analysis Methods

The physiological and officinal functions of phytosterols are of great significance, and recent dietary guidelines have underscored the significance of incorporating them into a balanced diet. Furthermore, it exhibits inhibitory effects on tumor growth, stimulates cellular immunity, possesses anti-inflammatory, antioxidant, and antidiabetic properties. To gain a more comprehensive understanding of the role of phytosterols in public health, it is crucial to establish simple, rapid, eco-conscious, efficient, and highly sensitive techniques for their extraction and determination across various matrices. This review presents a thorough overview of various techniques used for extracting and analyzing phytosterols in diverse plant-derived foods, encompassing a range of advanced technologies like solid-phase extraction, microextraction, supercritical fluid extraction, QuEChERS, alongside traditional approaches. The detection techniques include liquid chromatography-based methods, gas chromatography-based methods, supercritical fluid chromatography, and other methodologies. Additionally, we conduct a thorough examination and comparison of various techniques while proposing future prospects.

Methacrylate bonded covalent organic framework monolithic column online coupling with high-performance liquid chromatography for analysis of trace estrogens in food

Covalent organic frameworks (COFs) are a burgeoning class of crystalline porous materials with unique properties and have been considered as a promising functional extraction medium in sample pretreatment. In this study, a new methacrylate-bonded COF (TpTh-MA) was well designed and synthesized via the aldehyde-amine condensation reaction, and the TpTh-MA was incorporated into poly (ethylene dimethacrylate) porous monolith by a facile polymerization reaction inside capillary to prepare a novel TpTh-MA monolithic column. The fabricated TpTh-MA monolithic column was characterized with scanning electron microscope, Fourier transform infrared spectrometer, X-ray diffraction, and N₂ adsorption-desorption experiments. Then, the homogeneous porous structure, good permeability and high mechanical stability of TpTh-MA monolithic column was used as separation and enrichment media of capillary microextraction, which was coupled with high-performance liquid chromatography fluorescence detection for online enrichment and analysis of trace estrogens. The main experimental parameters influencing the extraction efficiency were systematically investigated. The adsorption mechanism for three estrogens was also explored and discussed based on hydrophobic effect, π-π affinity and hydrogen bonding interaction, which contributed to its strong recognition affinity to target compounds. The enrichment factors of the TpTh-MA monolithic column micro extraction method for the three estrogens were 107-114, indicating a significant preconcentration ability. Under optimal conditions, a new online analysis method was developed and exhibited good sensitivity and wide linearity range of 0.25-100.0 µg·L^-1 with a coefficient of determination (R²) higher than 0.9990 and a low limit of detection with 0.05-0.07 µg·L^-1. The method was successfully applied for online analysis of three estrogens of milk and shrimp samples and the recoveries obtained from spiking experiments were in range of 81.4-113% and 77.9-111%, with the relative standard deviations of 2.6-7.9% and 2.1-8.3% (n = 5), respectively. The results revealed the great potential for the application of the COFs-bonded monolithic column in the field of sample pretreatment.

Novel chemically cross-linked self-molding particulate sorbents as solid-phase extraction media

Here, we describe novel, chemically cross-linked, self-molding particulate polymer sorbents that are utilized as a molding-type solid-phase extraction medium (M-SPEM), which exhibits high permeability and rigidness. To fabricate such M-SPEM, first, polyethyleneimine (PEI)-modified reversed-phase (RP)-type particulate sorbents were synthesized, thereafter, they were chemically cross-linked by a polymer having many epoxy groups together with additional PEI. By optimizing the binding conditions of the particulate sorbents, the resultant M-SPEM has almost the same adsorption properties as the corresponding unmolded particulate sorbent for some polar (e.g., uracil and adenine) compounds. The binding technique proposed here is expected to facilitate the fabrication of molding-type sorbents and improve the performance of the SPE procedure.

Functionalized monolithic columns: Recent advancements and their applications for high-efficiency separation and enrichment in food and medicine

The chromatographic column is the core of a high-performance liquid chromatography (HPLC) system, and must have excellent separation efficiency and selectivity. Therefore, functional modification materials for monolithic columns have been rapidly developed. This study is a systematic review of the recently reported functionalized monolithic columns. In particular, the study reviews the types of functional monomers under different modification conditions, as well as the separation and detection techniques combined with chromatography, and their development prospects. In addition, the applications of functionalized monolithic columns in food analysis, biomedicine, and the analysis of active ingredient of Chinese herbal medicines in recent years are also discussed. Also reviewed are the functionalized monolithic columns for qualitative and quantitative analysis. It provided a reference for further development and application of organic polymer monolithic columns.

Simultaneous separation and quantitation of three phytosterols from the sweet potato, and determination of their anti-breast cancer activity

The present study provides the method for simultaneous separation and determination of concentration and evaluates anti-breast cancer activity of three phytosterols from the sweet potato (Ipomoea batatas L.): daucosterol linolenate (DLA), daucosterol linoleate (DL), and daucosterol palmitate (DP). A cell viability assay revealed that the three phytosterols had a stronger inhibitory effect on MCF-7 than MDA-MB-231 breast cancer cell line, and had no effects on non-tumorigenic MCF-10A cells. In vivo experiments demonstrated that DLA, DL, and DP suppressed tumor growth in MCF-7 xenograft breast cancer model in nude mice. Given the anti-breast cancer activity of DLA, DL, and DP, an HPLC method for the determination of their content in the sweet potato was developed. The method had satisfactory linearity (R² = 0.9992-0.9999). The limits of detection (LOD) were in the range of 2.5-10 μg/mL, the limits of quantification (LOQ) were 5-25 μg/mL, and the recovery rates were 97.64-103.02%. Additionally, the HPLC method was successfully validated in eight sweet potato cultivars. This novel technique can be applied for the determination of DLA, DL, and DP in the sweet potato.