This study focuses on the synthesis, characterization, and adsorption performance of a series of UiO-66-based materials for the adsorption of alkylphenols such as bisphenol A (BPA), 4-butylphenol (4-BP), and 4-pentylphenol (PP). The UiO-66 series, including UiO-66-NH2-50 %, mesoporous UiO-66 (HCl-meso-UiO-66), and 4-pentylbenzoic acid-modified 4-meso-UiO-66, were prepared through a combination of thermal and chemical modifications. Transmission electron microscopy analyses confirmed the successful creation of mesoporous structures, while FT-IR and XPS spectroscopy validated the chemical modifications. The adsorption performance was evaluated through kinetic and isotherm studies, employing pseudo-first-order and pseudo-second-order models as well as Langmuir and Freundlich isotherm models. The results indicated rapid initial adsorption rates, with equilibrium reached within 40 min. The pseudo-second-order model provided the best fit for the kinetic data, while the Freundlich model better described the adsorption behavior for 4-BP and PP, suggesting multilayer adsorption on heterogeneous sites. Thermodynamic studies indicated that 4-BP adsorption is endothermic and non-spontaneous, while BPA and PP adsorption exhibited exothermic and spontaneous characteristics. The study also explored the adsorption mechanisms, highlighting the importance of hydrophobic interactions and size-exclusion effect in the adsorption process. Hydrogen bonding and it-it stacking, although present, was not the primary determinant. The findings underscore the potential of 4-meso-UiO-66, which exhibited the highest adsorption capacity, particularly for PP, driven by its enhanced pore accessibility, despite a smaller surface area compared to UiO-66-NH2-50 %, and hydrophobicity. This work provides valuable insights into the design of efficient adsorbents for alkylphenols enrichment and separation.

This study investigates the adsorption behavior of biogenic amines (BAs) using mesoporous silica materials, specifically SBA-15 and SBA-16, as well as their carboxyl-functionalized derivatives (SBA-15-C and SBA-16-C). The materials were synthesized and characterized using Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, and nitrogen adsorption-desorption analyses, confirming successful functionalization and the preservation of mesoporous structures. Adsorption kinetics and isotherms were evaluated to assess the efficiency and capacity of these materials in adsorbing phenylethylamine and tryptamine. The results demonstrated that carboxylation, despite reducing pore size and surface area, significantly enhanced the adsorption capacity. SBA-15-C exhibited the highest adsorption capacity, with a maximum of 129.9 mg g(-1), surpassing other recently reported adsorbents. The primary adsorption mechanisms were identified as hydrogen bonding and N-H bond interactions between the -NH2 groups of BAs and the -OH or -COOH groups on the SBA surfaces. Additional mechanisms, including ion-dipole interactions and size exclusion effects, also contributed to the adsorption process. The improved performance of carboxylated SBA materials is attributed to their increased negative surface charge, which enhances their affinity for positively charged BAs. Additionally, density functional theory calculations and molecular docking simulations were employed to further investigate the interaction mechanisms between the adsorbents and BAs, confirming the significance of electrostatic interactions and hydrogen bonding at specific binding sites. These findings suggest that carboxylated SBA-15 is highly effective for the selective extraction of BAs from complex matrices, offering potential for practical applications in food safety.

Mesoporous silica materials, SBA-15 and SBA-16, that functionalized with the carboxyl, vinyl and amino groups were synthesized in this study. The spectroscopic analysis evaluated the physicochemical characteristics of these materials. These materials were coated on the arrow-typed solid phase microextraction (SPME Arrow) to extract biogenic amines (BAs). The influences of these materials' functional groups and spatial structure on their extraction efficiency were studied. Carboxyl group modified SBA-15 (SBA-15-C) exhibited the highest extraction capacity to BAs because of the size exclusion effect and the electrostatic interaction. The extraction and desorption parameters of the SPME Arrow method were optimized. The SBA-15-C-SPME Arrow was coupled with a gas chromatography-mass spectrometry (GC-MS) system for the determination of BAs in animal-derived meat samples, which showed good repeatability (RSD<15%), satisfactory linear range (0.01–1mgkg–1), low limit of detection (0.001–0.004mgkg–1), and high recovery (84–129%). This method showed excellent applicability for the quantitative and qualitative detection of six BAs in animal-derived meat samples. This study provides new insight into the development of new sorbents with high extraction capacity to BAs for the selective and sensitive determination of BAs in complex meat samples.

This study presents a method utilizing solid-phase microextraction Arrow (SPME Arrow) combined with ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) for the selective detection of three veterinary drugs-thiabendazole, sulfamethazine, and clenbuterol-in milk and pork. Two-dimensional metal-organic framework nanosheets (2D-MOFs) were employed as coating materials for the SPME Arrow. Three types of 2D-MOFs (Ni, Mn, and Co based) were synthesized and characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and a physical adsorption analyzer. The 2D-MOF coatings were fabricated using the electrospinning technique, with polyacrylonitrile (PAN) serving as the binder. Comparative analysis of the three 2D-MOF coatings revealed that 2D-Ni-MOF was the optimal coating material for the SPME Arrow. Optimization of the coating preparation conditions and SPME procedures included determining the optimal mass ratio of 2D-Ni-MOF to PAN, electrospinning time, and extraction and desorption parameters. Equilibrium extraction was achieved within 60 min, and desorption was completed within 30 min. Subsequently, the 2D-Ni-MOF-SPME Arrow-UPLC-Q-TOF-MS method was established and validated under optimal conditions, demonstrating high precision with inter-day precision ranging from 3.8 % to 9.5 % and intra-day precision ranging from 5.1 % to 11.5 %. The reusability study indicated that the extraction performance of the new SPME Arrow remained consistent after 90 adsorption-desorption cycles. The method exhibited linearity in milk and pork over the ranges of 0.002-5 mu g L-1 and 0.01-5 mu g L-1, respectively. The detection limits in milk and pork were 0.001-0.004 mu g L-1 and 0.003-0.007 mu g L-1, respectively. This method demonstrated excellent applicability for determining residues of the three veterinary drugs in milk and pork.

Meat adulteration is a challenge faced by the global food industry. However, existing protein-based methods or DNA-based polymerase chain reactions are time-consuming and require specialist devices. Therefore, a rapid and on-site assay is urgently needed for identifying meat species. In this study, we developed a duplex recombinase polymerase amplification-lateral flow strip (dRPA-LFS) assay coupled with a rapid DNA extraction method (utilizing the UiO-66 coated stick as the DNA isolation device, and the isolation can be completed in 1minute, including lysis, washing, and desorption in three steps) for the identification of pork and chicken ingredients. Targeted genes, the pork (Porcine) mitochondrial ND2 gene and chicken (Gallus gallus) cytochrome B gene, were designed with primers and probes. The whole dRPA-LFS detection procedure can be finished within 18.5minutes (including 1minute of rapid DNA extraction, 15minutes of dRPA amplification, and 2.5minutes of LFS semi-quantitative detection by the naked eye), and the result can also be quantified by ImageJ software within 15minutes. No positive amplification was observed in beef, lamb, duck, rabbit, goose, ostrich, and horse meat DNA. This assay is sensitive and can detect as low as 0.1% (wt%) of pork and chicken in simulated adulterated meat mixtures. This assay was successfully applied to the authentication identification of 30 commercial beef and lamb products.

In recent years, with growing concern worldwide about meat and meat product adulteration, dozens of DNAbased isothermal amplification techniques have been developed and applied to detect meat adulteration. Thus, we evaluated four mainstream isothermal amplification techniques, including loop-mediated isothermal amplification (LAMP), denaturation bubble-mediated strand exchange amplification (SEA), cross-priming amplification (CPA), and recombinase polymerase amplification (RPA) focusing on the limit of detection, simplicity, amplification time and cost to confirm the most effective and suitable method for point-of-care testing (POCT) of chicken and chicken product authenticity. The LAMP, CPA, and RPA primers all targeted the chicken mitochondrial cytochrome b gene. The SEA primers were provided by the SEA kit. All methods showed good specificity to chicken. Among them, LAMP, CPA, and RPA have the lowest detection limit, with 1.2 pg mu L-1. As low as 0.1% chicken in mutton can be detected in LAMP and RPA methods. Although RPA costs 10 times more than LAMP, the system and primers of LAMP are too complex. Therefore, it must be admitted that RPA is the most suitable method in multiplex detection, and LAMP is much better than the other three methods in singleplex detection. Our research provides an excellent reference value for the rapid on -site detection of meat and meat product adulteration.

A solid-phase microextraction (SPME) Arrow and high-performance liquid chromatography-UV detector (HPLC-UV, detection at 225 nm) based method was developed for the selective determination of nine alkylphenols (APs) in milk. The functionalized mesoporous UiO-66 (4-meso-UiO-66) was utilized as the new coating material, which was synthesized by post-modification of pore-expanded UiO-66-NH2 by an esterification reaction with 4-pentylbenzoic acid. It was fully characterized by X-ray photoelectron spectroscopy (XPS), fourier transformation infrared spectrometry, nitrogen sorption-desorption test, scanning electron microscopy, transmission electron microscopy, and X-ray diffractometer. The characterization results showed the ester groups and benzene rings were introduced into the 4-meso-UiO-66, and the mesoporous structure was predominant in the 4-meso-UiO-66. The extraction mechanism of 4-meso-UiO-66 to APs is the synergistic effect of Zr-O electrostatic interaction and the size exclusion effect resulting from XPS, selectivity test, and nitrogen sorption-desorption test. The electrospinning technique was utilized to fabricate the 4-meso-UiO-66 coated SPME Arrow and polyacrylonitrile (PAN) was used as the adhesive. The mass rate of 4-meso-UiO-66 to PAN and the electrospinning time were evaluated. The extraction and desorption parameters were also studied. The linear range of this method was 0.2–1000 μg L–1 with a coefficient of determination greater than 0.9989 under the optimal conditions. The detection limits were 0.05–1 μg L–1, the inter-day and intra-day precision (RSD) were 2.8–11.5

A rapid, portable, simple, low-cost, and high-throughput DNA isolation method was developed for the quantitative identification of meat adulteration based on mesoporous UiO-66 coated solid phase microextraction (SPME) devices. The high-throughput DNA extraction system consists of 96 UiO-66 SPME devices and a polyformaldehyde plate, which can extract DNA from 96 livestock and poultry meat samples simultaneously. At the same time, several parameters of the high throughput DNA isolation method were optimized, including lysis buffer volume, elution buffer volume, lysis time and elution time, etc. Compared with the single DNA isolation device, the 96-SPME high-throughput extraction system maintains the original good universality, reproducibility, chemical stability, and reusability. On this basis, it obtained higher DNA concentration (80 +/- 34 ng mu L 1), satisfactory DNA purity (A260/A280=2.4) and shorter extraction time (less than 7.2 s per sample), which are much more convenient and efficient than the conventional kit method and the single SPME DNA isolation method. In addition, the conventional multiplex polymerase chain reaction and real-time polymerase chain reaction techniques were used for the qualitative and quantitative detection of meat adulteration. The DNA obtained from this extraction method is highly reproducible and sensitive for the identification of duck ingredients in beef, with a detection range of 1-100 % and a minimum detection limit of 1 % (w/w).

Beta-lactam antibiotics (BLAs) are not only important in animal husbandry but are also unavoidable contaminants in milk. The gradual accumulation of BLAs in the human body due to increased milk intake can cause direct harm to human health. Therefore, developing selective and sensitive methods for rapid BLA detection is essential. In this study, a specific electrochemical receptor sensor based on penicillin-binding proteins (PBPs) was established. PBP1a and PBP2x, which have high affinity and specificity for the six BLAs, were used as the receptors and their performance was compared. The sensor was fabricated by sequentially immobilizing a graphene/chitosan nanocomposite, penicillin G (PENG), and Nafion on the surface of a glassy carbon electrode using a convenient casting approach. The mechanism of the electrochemical receptor sensor involved direct competitive inhibition of the binding of the graphene/chitosan/PENG composite to the PBPs by the free BLAs in the solution. The PENG-PBPs complex resisted the interaction between [Fe(CN)(6)](3-/4-) ions and the glassy carbon electrode, thereby decreasing the current signal of the BLAs. The BLA concentration was quantified using differential pulse voltammetry mode. The graphene/PENG/chitosan/Nafion-based electrochemical assay demonstrated good selectivity against other antibiotic residues frequently detected in milk. Under optimized conditions, the detection limits of this method ranged from 0.24 to 1.39 ngmL(-1), which are much lower than the maximum residue limits set by China and the EU. Moreover, the sensor showed a satisfactory recovery rate of 98.8 +/- 5.8%-103.2 +/- 7.1%. The total analysis time involved only one incubation step, and the entire analysis could be completed within 35 min.

An immunoassay method based on penicillin-binding protein (PBP) was developed for the quantitative determination of 10 kinds of beta-lactam antibiotics (BLAs). First, two kinds of PBPs, which are named PBP1a and PBP2x, were expressed and purified, and they were characterized by SDS-PAGE and western blotting analysis. Then, the binding activity of PBP1a and PBP2x to template BLAs, cefquinome (CEFQ) and ampicillin (AMP), was determined. The effect of the buffer solution system, e.g., pH, ion concentration, and organic solvent, on the immune interaction efficiency between PBPs and BLAs was also evaluated. In the end, the PBP-based immunoassay method was developed and validated for the detection of 10 kinds of BLAs. Under optimal conditions, PBPs exhibited high binding affinity to BLAs. In addition, this method showed a high sensitivity for the detection of 10 kinds of BLAs with the limits of detection from 0.21 to 9.12 ng/mL, which are much lower than their corresponding maximum residual limit of European Union (4-100 ng/mL). Moreover, the developed PBPimmunoassay was employed for BLA detection from milk samples, and satisfactory recoveries (68.9-101.3 %) were obtained.

Microplastics (MPs) have become an important global issue in recent years. However, MPs in the soil have received far less attention than water. Effective and nondestructive extraction of MPs is important for studying MPs in agricultural soils. This study uses different floatation solutions as experiments and uses MgCl2 as the floatation solution of the density extraction method. Five types of standard MPs (PE, PP, PS, PVC, and PET) are used as the objects of this experiment. The recovery of the two particle sizes was between 90.82% and 109.69%. The extracted standard MPs were then subjected to IR and Raman spectroscopic analysis, and the results showed that Raman spectroscopy was more suitable for the identification of the extracted MPs. Finally, this method collected and verified a vast number of soil samples and further analyzed the abundance and characteristics of the collected MPs.

The production and use of organophosphate esters (OPEs) as substitutes for traditional halogenated flame retardants is increasing, resulting in greater global concern related to their ecological risks to marine environments. In this study, polychlorinated biphenyls (PCBs) and OPEs, representing traditional halogenated and emerging flame retardants, respectively, were studied in multiple environmental matrices in the Beibu Gulf, a typical semi-closed bay in the South China Sea. We investigated the differences in PCB and OPE distributions, sources, risks, and bioremediation potentials. Overall, the concentrations of emerging OPEs were much higher than those of PCBs in both seawater and sediment samples. Sediment samples from the inner bay and bay mouth areas (L sites) accumulated more PCBs, with penta- and hexa-CBs as major homologs. Chlorinated OPEs were prevalent in both seawater and sediment samples from the L sites, whereas tri-phenyl phosphate (TPHP) and tri-n-butyl phosphate (TNBP) were predominant at the outer bay (B sites) sediment samples. Source identification via principal component analysis, land use regression statistics, and δ13C analysis indicate that PCBs were mainly sourced from the atmospheric deposition of sugarcane and waste incineration, whereas sewage inputs, aquaculture, and shipping activity were identified as sources of OPE pollution in the Beibu Gulf. A half-year sediment anaerobic culturing experiment was performed for PCBs and OPEs, and the results only exhibited satisfactory dechlorination for PCBs. However, compared with the low ecological risks of PCBs to marine organisms, OPEs (particularly trichloroethyl phosphate (TCEP) and TPHP) exhibited low to medium threats to algae and crustaceans at most sites. Given their increasing usage, high ecological risks, and low bioremediation potential in enrichment cultures, pollution by emerging OPEs warrants close attention.

基于磁分离富集核酸适配体技术,构建了一种新型比色型适配体传感器,用于快速检测大田软海绵酸.巯基修饰的固定链自组装到磁珠上,与适配体链杂交反应后,再加入带有HRP-纳米金标记的探针链与适配体链的3端结合.从而形成一个带有HRP-纳米金标记的适配体传感器,催化TMB产生变色反应,测定在A610/A520的值.在最优条件下,传感器具有良好的线性检测范围(0.2～2.0 ng·mL-1)和较高的灵敏度,R2=0.9989,检测限(LOD)0.044 ng·mL-1,在加标回收实验中时,平均回收率为82.23％～98.73％,相对标准偏差RSD均小于11％,本研究成功构建了一种用于大田软海绵酸快速、高灵敏度的显色型适配体生物传感器,为大田软海绵酸的快速检测提供了新的思路和研究基础.

建立了QuEChERS结合气相色谱-质谱测定果脯中16种多环芳烃的分析方法.优化了前处理的条件,实现了不同类别多环芳烃的同时测定.实验结果表明,16种目标物在1～1000 ng·mL-1浓度范围线性关系良好,相关系数(r)为0.9980～0.9999.在1、10、200μg·kg-13个加标水平下,加标平均回收率为78.3％～104.3％,相对标准偏差为1.4％～6.4％(n=6),方法的检出限为0.43 ng·mL-1,定量限为1 ng·mL-1.该方法具有较高的灵敏度,实验操作简便,能够满足日常检测分析要求,适合大批量样品处理.

With the rapid increase in the use of plastic films, microplastic (MP) pollution in agricultural soils has become a global environmental problem. Propiconazole is widely used in agriculture and horticulture; however, its role in plastic film degradation remains elusive. Butylene adipate-co-terephthalate (PBAT) and polyethylene (PE) films were used to analyze the effects of propiconazole on plastic film and MP degradation. We identified the surface morphologies of PBAT and PE at different propiconazole concentrations and soil pH values, as well as the adsorption and release characteristics of heavy metals during the degradation process via scanning electron microscopy, Fourier transform infrared spectroscopy and inductively coupled plasma mass spectrometry. Propiconazole accelerated the degradation of MPs, adsorption of heavy metals (Ni and Zn), and release of Sn at low concentrations (≤40 mg/kg); however, these effects were evidently absent at a high concentration (120 mg/kg). Furthermore, MPs were more prone to degradation in acidic or alkaline soils than in neutral soil when they coexisted with propiconazole. Hence, we suggest that PBAT and PE plastic films may not be suitable for application in acidic and alkaline soils with propiconazole, because of shorter rupture time and more heavy metal adsorption. PBAT degraded faster, absorbed and released more heavy metals than PE. Under all tested conditions, the heavy metal contents in MPs gradually approached those in soil, which proves that MPs are carriers of heavy metal pollutants. These results may help in assessing the impact of MPs on soil environments and provide a theoretical basis for the standardized propiconazole and plastic film usage.

Taxifolin is known to have multiple biological functions. It has been widely used as a multifunctional food additive, and consequently, the global demand for taxifolin is increasing. The main method for taxifolin production is an extraction from larch wood, but the global resources of larch are limited. Astilbin, taxifolin-3-o-rhamnoside, is abundant in many plants and much more readily available, meaning taxifolin can be obtained by deglycosylation of astilbin. In this study, a fungal strain, Aspergillus fumigatus SQH4, was isolated from an enrichment culture of Smilax glabra rhizome to achieve the deglycosylation reaction. A culture of SQH4, adjusted to pH 6.5, with 5 g/L astilbin achieved a yield of taxifolin of 91.3% after biotransformation for 14 h at 35 °C. These findings offer an alternative method for the production of taxifolin.

检验检测机构资质认定现场评审自突发疫情后受到了前所未有的影响,而检验检测机构资质认定刻不容缓,特别是针对口罩、防护用品等抗疫物资的检验检测,为此国家市场监管总局紧急出台了疫情防控期间加强检验检测认证管理的相关指导意见,帮助检验检测机构更好地服务于企业的复产复工,同时切实解决因疫情或其他原因而无法实施现场评审的情况,提供了解决办法.

For the efficient biotransformation of cucurbitacin B 2-o-β-d-glucoside (CuBg) to cucurbitacin B (CuB) in Cucumis melo pedicel extracts, the β-glucosidase gene bglS—consisting of 1344 bp (447 amino acids) from Streptomyces sp. RW-2—was cloned and expressed in Escherichia coli BL21(DE3). The activity of recombinant β-glucosidase with p-nitrophenyl-β-d-glucoside (pNPG) as a substrate was 3.48 U/mL in a culture. Using the recombinant β-glucosidase for the biotransformation of C. melo pedicel extracts, CuBg was converted into CuB with a conversion rate of 87.6% when the concentration of CuBg was 0.973 g/L in a reaction mixtures. The concentration of CuB in C. melo pedicel extracts was improved from 13.6 to 20.2 g/L after biotransformation. The present study provides high-efficiency technology for the production of CuB from its glycoside by biotransformation.

目的:提高葫芦素B葡萄糖苷(CuBg)生物转化为葫芦素B(CuB)的得率.方法:采用单因素实验,优化链霉菌(Streptomyces sp.)RW-2菌株产β-葡萄糖苷酶培养基中的碳源、氮源、初始pH和培养时间.结果:200 g·L-1的马铃薯煮沸后汁液中,加入30 g·L-1的蔗糖、14 g·L-1的大豆粉,调节pH为7.5,作为产酶培养基,接种链霉菌RW-2孢子液后,于30℃、180 r·min-1条件下培养4 d,除去菌体的粗酶液转化甜瓜蒂提取物,CuBg转化为CuB的得率最高,达到69.1％.结论:在马铃薯汁中仅加入蔗糖和大豆粉作为链霉菌RW-2产β-葡萄糖苷酶的培养基,具有组分少,配制方法简单,成本低的优点.

海洋生物毒素是海洋生物体内存在的一类高活性特殊代谢成分,大多数具有剧烈毒性,给人类健康和安全带来严重威胁.目前针对海洋生物毒素的检测主要采取小鼠生物检测法、免疫分析法、大型仪器检测法和毛细管电泳法,但均存在一定的局限性.因此,为更加高效和特异性地检测海洋生物毒素,核酸适配体技术成为这一领域的重要选择之一.本文旨在通过介绍核酸适配体技术的原理及优势,来表明其在海洋生物毒素检测中应用的可行性,以及该方法的研究现状和发展趋势.