Ultrasonic-microwave synergistic supramolecular solvent liquid-liquid microextraction of trace biogenic amines in fish and beer based on solidification of floating organic droplet

Dispersive liquid-liquid microextraction based on temperature-responsive supramolecular solvent followed by HPLC-DAD for the determination of pyrethroid pesticides in tobacco samples

A novel temperature-responsive supramolecular solvent was prepared with cetyltributylphosphonium tetrafluoroborate and sodium citrate. It served as the extraction solvent of dispersive liquid-liquid microextraction for the extraction and enrichment of pyrethroids in tobacco samples. In this study, the preparation of the temperature-responsive supramolecular solvent and the extraction of the target analytes were integrated into one step, which simplified the experimental process. Due to the low melting point of the prepared supramolecular solvent, the traditional liquid-liquid separation can be converted to solid-liquid separation at low temperatures. This conversion facilitates precise collection of the supramolecular solvent and reduces the loss of target analytes. The composition, structure, physicochemical properties, and micromorphology of the supramolecular solvent were characterized. The formation and extraction mechanism of supramolecular solvent were explored, and the extraction conditions were optimized. The results indicated that good linearity of target analytes (R2 > 0.9998) was obtained within the linear range. The limits of detection and quantification for the five pyrethroids were in the range of 0.25-0.50 μg L-1 and 0.85-1.65 μg L-1, respectively. The present method can be used for the analysis of pyrethroid pesticide residues in tobacco samples.

Applications of Microextraction Technology for the Analysis of Alcoholic Beverages Quality: Current Perspectives and Future Directions

Alcoholic beverages are loved by the majority of consumers because of their diverse characteristics and rich nutritional value; thus, ensuring their quality is necessary for maintaining the rapid development of the alcoholic beverage industry. Due to trace levels of various quality factors and the complexity of the beverage body matrix, pretreatment is usually required before analysis. Among the many pretreatment methods available, microextraction has attracted increasing attention because it aligns with the development direction of green chemistry. This review surveys advancements in microextraction techniques pertaining to three quality aspects in the most frequently consumed alcoholic beverages: baijiu and huangjiu (spirits) and wine and beer (fermented alcoholic drinks). Furthermore, new directions in their development are discussed.

A novel approach based on supramolecular solvents microextraction for quick detection of perfluoroalkyl acids and their precursors in aquatic food

Per-and polyfluoroalkyl substances (PFASs) have garnered significant attention owing to their prevalence and adverse effects on humans. The direct dietary intake of perfluoroalkyl acids (PFAAs) and PFAAs precursors (pre-PFAAs) biotransformation are considered major contributors to human exposure to PFASs. However, little information is available on analytical methods for the simultaneous detection of PFAAs and pre-PFAAs. In the present study, a single-step sample-treatment-based supramolecular solvents-dispersed liquid-liquid microextraction (SUPRASs-DLLME) technique was established for the analysis of 16 PFAAs and 7 pre-PFAAs in aquatic food. SUPRASs were synthesized using 1-heptanol (3 mL) and tetrahydrofuran (4 mL), which were self-assembled in water. The parameters for microextraction, such as extraction method and enrichment capacity, were optimized. Under the optimum conditions, the limit of detection (LOD) and limit of quantification (LOQ) were 0.03-0.15 ng·g-1 and 0.1-0.5 ng·g-1, respectively. Good linearities (R2 > 0.996) were obtained for all the target compounds, and the recoveries ranged 81.1-120 % with relative standard deviations (RSDs) lower than 20 %. This method was applied to the analysis of 16 PFAAs and 7 pre-PFAAs in aquatic food samples (crabs, prawns, and fish). This study provides a new idea for analyzing other pollutants in biological samples.

Detection of urea in milk by urease-inorganic hybrid nanoflowers combined with portable colorimetric microliter tube

A simple one-pot green synthesis method was used to prepare urease-inorganic hybrid nanoflowers (UE-HNFs), which had a high surface-to-volume ratio to improve enzyme catalytic efficiency and make urease reusable. A portable colorimetric microliter tube based on urease-inorganic hybrid nanoflowers (UE-HNFs-PCMT), as an urea colorimetric biosensor, was developed for determining urea concentration in milk. The combination of urea colorimetric biosensor and a smartphone is used for capturing the colour change of milk after reaction. There was a good linear relationship between colour intensity of the image (Δ intensity) and urea concentration (43-600 mg L-1), with a detection limit of 12.81 mg L-1. UE-HNFs-PCMT has the advantages of no need for complex equipment, easy operation, reusability, low detection cost, good portability, and environmental friendliness and can achieve urea detection in milk.

"One-Pot" Readout Cyano-Programmable SERS-Encoded Platform Enables Ultrasensitive and Interference-Free Detection of Multitarget Bioamines

Surface-enhanced Raman spectroscopy (SERS) detection platforms with high signal-to-noise ratio in the "biological-silent" region (1800-2800 cm-1) are presently being developed for sensing and imaging applications, overcoming the limitations of traditional SERS studies in the "fingerprint" region. Herein, a series of cyano-programmable Raman reporters (RRs) operating in the "biological-silent" region were designed based on 4-mercaptobenzonitrile derivatives and then embedded in core-shell Au@Ag nanostars using a "bottom-up" strategy to provide SERS enhancement and encapsulation protection. The approach enabled the "one-pot" readout interference-free detection of multiple bioamines (histamine, tyramine, and β-phenethylamine) based on aptamer-driven magnetic-induced technology. Three cyano-encoded SERS tags resulted in separate SERS signals for histamine, tyramine, and β-phenethylamine at 2220, 2251, and 2150 cm-1, respectively. A target-specific aptamer-complementary DNA competitive binding strategy allowed the formation of microscale core-satellite assemblies between Fe3O4-based magnetic beads and the SERS tags, enabling multiple SERS signals to be observed simultaneously under a 785 nm laser excitation laser. The LODs for detection of the three bioamines were 0.61 × 10-5, 2.67 × 10-5, and 1.78 × 10-5 mg L-1, respectively. The SERS-encoded platform utilizing programmable reporters provides a fast and sensitive approach for the simultaneous detection of multiple biomarkers, paving the way for routine SERS analyses of multiple analytes in complex matrices.

Microbial contribution to 14 biogenic amines accumulation in refrigerated raw and deep-fried hairtails (Trichiurus lepturus)

Biogenic amines (BAs) produced by microbial decarboxylation of amino acids are crucial toxic nitrogenous compounds in fish. An optimized ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method with simple pretreatment was established to detect 14 BAs in both raw (control check, CK) and deep-fried (DF) hairtails. This method exhibited a good linear relationship with average recoveries of 73.3-120.0 % and relative standard deviations of 2.5-10.0 %, respectively. The total BAs in CK and DF hairtails decreased sharply to 338.2 and 25.3 mg/kg on the 9th day, respectively. Four BAs, including cadaverine (CAD), histamine (HIS), tyramine (TYR), and putrescine (PUT) accounted for 92.5-99.9 % of total BAs were selected as the dominant BAs. Bacterial analysis showed that the abundance of DF was relatively low. Further correlation analysis proved that Vibrio had a significant (p < 0.05) positive correlation with total BAs and could be the main BA-producing bacterium in DF hairtail. This work provides new evidence of the accumulation of BAs in refrigerated hairtail.

Recent advances in inspection technologies of food safety health hazards for fish and fish products

The development of reliable and sensitive detection methods is essential for addressing the escalating concerns surrounding fish and fish products, driven by increasing market demands. This comprehensive review presents recent advances in detection approaches, specifically focusing on microplastic, biological, and chemical hazards associated with these products. The overview encompasses 21 distinct detection methods, categorized based on the type of hazard they target. For microplastic hazards, six methods are visual, spectroscopic, and thermal analyses. Biological hazard identification relies on six approaches employing nucleic-acid sequence, immunological, and biosensor technologies. The investigation of chemical hazards encompasses ten methods, including chromatography, spectroscopy, mass spectrometry, immunological, biosensor, and electrochemical techniques. The review provides in-depth insights into the basic principles, general characteristics, and the recognized advantages and disadvantages of each method. Moreover, it elaborates on recent advancements within these methodologies. The concluding section of the review discusses current challenges and outlines future perspectives for these detection methods. Overall, this comprehensive summary not only serves as a guide for researchers involved in fish safety and quality control but also emphasizes the significance of staying abreast of evolving detection technologies to ensure the continued safety of fish and fish products in response to emerging food safety hazards.