The recovery of gold from electronic waste and industrial leachates has attracted great interest. However, developing highly efficient and selective adsorbents for capturing trace gold remains a challenge. Herein, an alkyne-based covalent organic framework (TAPB-BPTA COF) was synthesized at room temperature and employed for Au(III) capture for the first time. The introduction of alkyne groups onto TAPB-BPTA COFs endowed it with an ultrahigh adsorption capacity of up to 2311.9 mg g-1 (calculated maximum adsorption capacity) toward Au(III), which was 4-fold higher than that of the counterpart COFs without alkyne groups. Furthermore, the TAPB-BPTA COFs showed high selectivity, fast adsorption kinetics, and excellent regeneration ability. Characterizations and calculations revealed that the synergistic effect of imine bonds and alkyne groups in TAPB-BPTA COFs played a crucial role in promoting Au(III) capture. Encouraged by the superior performance, the TAPB-BPTA COFs were further applied to capture trace Au(III) in aqueous solutions and electronic waste. The results demonstrated that high extraction efficiencies for Au(III) were achieved all above 93.6%. In addition, the selectivity for Au(III) was characterized by partition coefficients (Kd), and the Kd was 65,810.3 mL g-1 of TAPB-BPTA COFs for Au(III) in the leachates of CPUs, approximately 15,000 and 1000 times higher than those of Ni(II) and Cu(II), respectively. This work not only expands the application of COFs in separation science but also provides a promising strategy to capture trace Au(III) from complex samples.

Saccharides are a sort of ubiquitous and vital molecules within the whole life. However, the application of saccharides analysis with matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is restricted by their low ionization efficiency and the instability of the sialic acid fraction. Derivatization strategy based on nonreductive amination provides a good solution, however, this is often time consuming and may result in sample loss due to removal of excessive derivatization reagents. Herein, hydralazine (HZN) was utilized as a reactive matrix for labeling reducing saccharides directly on MALDI target which eliminated tedious sample preparation and avoided sample loss. After optimization, effective and reproducible on-MALDI-target derivatization of neutral and acidic saccharides was achieved in both positive and negative modes. Compared with 2,5-dihydroxybenzoic acid (DHB) and 9-aminoacridine (9-AA), HZN improved the detection sensitivity of reducing saccharides and provided more abundant fragment ions in MS/MS analysis. Moreover, 26 kinds of neutral glycans and 5 kinds of sialic glycans were identified from ovalbumin (OVA) and bovine fetuin, respectively. Combined with the statistical models, this strategy could be used to distinguish and predict samples of 6 brands of beer, and discriminate 2 kinds of beer fermentation modes. In addition, HZN was applied for quantitative analysis of glucose in urine samples, and the obtained urine glucose concentrations of diabetic patients were consistent with the clinical test results, showing the potential of qualitative and quantitative analysis of reducing saccharides in complex samples.

A hollow microtubular covalent organic framework (denoted as TatDha-COF) was synthesized by solvothermal method for the enrichment and determination of quinones. The TatDha-COF showed large specific surface area (2057 m2 g−1), good crystal structure, ordered pore size distribution (2.3 nm), stable chemical properties and good reusability. Accordingly, a simple and efficient method based on dispersive solid-phase extraction (d-SPE) and atmospheric pressure gas chromatography tandem mass spectrometry (APGC-MS/MS) was developed for the determination of quinones in complex samples. The established method demonstrated a wide liner range, good linearity (r>0.9990), high enrichment factors (EFs, 24–69-folds) and low detection limits (LODs, 0.200–30.0 pg L−1, S/N≥3). On this basis, the suggested method was successfully applied to sensitively detect the eight ultratrace quinones in mice plasma. Overall, the established method has provided a powerful tool for the enrichment and detection of ultratrace quinones in complex samples, presenting the promising application of TatDha-COF in sample pretreatment.

Constructing advanced substrates with excellent features is promising for sensitive surface-enhanced Raman spectroscopy (SERS) detection. Here a novel capillary monolithic 3D structural-substrate SERS platform with Au@cDNA@Ag@Cyanine 3-aptamer nanoparticles (Au@cDNA@Ag@Cy3-Apt NPs) was fabricated for rapid, highly specific profiling of ultra-trace Bisphenol A (BPA). The proposed SERS platform combined both in-capillary SERS and aptamer-affinity recognition strategies, in which the superior SERS properties of Au-Ag NPs, aptamer selectivity, and the advantages of capillary monolith were integrated. A 3D hierarchically porous network was constructed in the monolithic column, which was endowed with rich hotspots for SERS, rapid sample permeation, and better analysis efficiency than most plane-shaped SERS modes. By varying the amount of Ag+ precursor, the Ag-shell thickness on SERS was finely tuned to guarantee Cy3 label in proximity to the plasmonic surface. Based on the biorecognition of aptamer, the selective identification of BPA occurred and exhibited a significant change in SERS intensity without obvious interference. As a result, the monolithic SERS platform featured facile operation, excellent specificity, and rapid analysis (10 min, much less than the solution-based or planar substrate SERS modes). Ultra-high sensitivity and robust reproducibility for BPA analysis was achieved with a low limit of detection (LOD) at 9.12 × 10-4 ng/L. The feasibility of this SERS platform for monitoring BPA in water and milk samples was also validated. This work lights a new access to capillary monolithic SERS-sensing platform for ultrasensitive and specific analysis of BPA.

Analysis of cis-diol compounds is essential, because they play important roles in cosmetics, food, pharmaceuticals, and living organisms. Herein, we describe the development of a matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-MS) method to analyse cis-diol compounds. In this method, a 6-borono-1-methylquinoline-1-ium (BMQI) reactive matrix was designed for in situ derivatisation of cis-diol compounds based on the boronate affinity interaction between boronic acid and cis-diol groups. Compared to traditional commercial matrices and other boronic acid reagents, BMQI can significantly accelerate the desorption/ionisation process, improve reproducibility, exhibit free background interference, and enhance signal intensity in the analysis of various cis-diol compounds even for amounts as low as 1 nmol. The BMQI-assisted laser desorption/ionisation mass spectrometry (LDI-MS) was successfully applied to the rapid screening and identification of sugar alcohols in different sugar-free foods. This work provides an alternative method to the LDI-MS analysis of cis-diol-containing molecules, and the method can be extended to other food samples and biofluids.

Phthalate esters (PAEs) are a typical group of endocrine-disrupting chemicals (EDCs) and widely found in the environment, which have attracted great concern due to the potential risks to environment and human health. It is urgent to develop a high-efficiency and high-sensitivity analytical approach for enrichment and determination of ultra-trace PAEs. Herein, magnetic covalent organic frameworks (Fe3O4@TAPB-DVA) were fabricated via a one-pot approach at room temperature and explored as a magnetic enrichment probe with high surface area (275.50 m2/g), good crystallinity, regular pore size distribution (3.1 nm) and outstanding saturation magnetization (26.5 emu/g). Accordingly, a simple and sensitive method based on magnetic solid-phase extraction (MSPE) combined with HPLC-MS/MS was established to detect ultra-trace PAEs from fine particulate matter (PM2.5) samples. The proposed method showed wide linear ranges (1-400 ng/L), good linearity (r > 0.9978) and high enrichment factors (EFs, 6.99-95.01 folds) with low detection limits (LODs) ranged from 0.01 to 0.5 ng/L (S/N ≥ 3). On this basis, the proposed method was substantially employed for sensitive detection of low- abundance PAEs from PM2.5 samples, suggesting the promising application of the Fe3O4@TAPB-DVA in sample enrichment.

Amyloid beta-peptide 1-42 (A beta 1-42) is one of the biomarkers of Alzheimer's disease, and its selective capture and quantitative detection are important for diagnosis and treatment of Alzheimer's disease. Herein, copper(II) ions-immobilized virus-like hollow covalent organic frameworks (V-HCOFs@Cu2+) were synthesized by a facile approach. The as-prepared V-HCOFs@Cu2+ showed unique morphology, ultrahigh specific surface (2552 m(2)/g), uniform mesoporous structure (3.2 nm), superior chemical stability and abundant binding sites. Based on these excellent properties, the V-HCOFs@Cu2+ could be adopted as an ideal enrichment probe for highly efficient capture of A beta 1-42, exhibiting high adsorption capacity (320 mg/g), and fast adsorption equilibration time (3 min). In addition, an attractive approach of the V-HCOFs@Cu2+-based matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) was developed for the rapid screening and quantitative analysis of A beta 1-42 in human serum by using C-peptide as an internal standard, which exhibited low limit of detection (LOD, 0.2 fmol/mu L), and satisfactory recovery. This work provides an alternative solution for enrichment of biomarkers and also offers the potential applications of COFs in clinical analysis (c) 2022 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Pyrite (FeS2) is known for one alternative to the promising anode materials for lithium-ion batteries (LIBs) on account of the low price, friendliness to environment and comparable higher theoretical capacity. Nonetheless, its long-term cycling performance is still not satisfied. In our present work, a FeS2@carbon composite coated with reduced graphene oxide (rGO) (rGO@FeS2@C) was synthesized to settle this problem. With the addition of rGO, the huge volume change was relieved and the big pulverization was also alleviated. When applied as the anode material for LIBs, the rGO@FeS2@C electrode could deliver outstanding electrochemical performance owing to its special structure. At 1 A g(-1), it could exhibit a high specific capacity of 820.7 mA h g(-1) after 300 cycles. Even if when the current density reaches to a higher degree of 5 A g(-1), rGO@FeS2@C could still exhibit a great specific capacity to 600.8 mA h g(-1) in the wake of 1100 cycles, which is one of the best results to FeS2 systems. In addition, we also compare its performance with the commercialized FeS2, further confirming the good electrochemical properties of rGO@FeS2@C.

Fast and highly efficient digestion of proteins is essential for high-throughput proteomic analysis. Herein, a facile approach was developed for self-assembly preparation of trypsin-immobilized capillary monolithic column and its application as an immobilized enzyme microreactor (IMER) for fast and highly efficient proteolysis was described. The performance of the trypsin-immobilized monolithic enzyme microreactor was evaluated by in-situ digestion of model proteins. The results showed that the trypsin-immobilized monolithic enzyme microreactor had much higher tryptic digestion efficiency than the free trypsin in solution, where the coverage of peptide sequences by mass spectrometry (MS)-based analysis could bear comparison with the free one, while the digestion time was dramatically shortened from 12 h to 16 s. Furthermore, the trypsin-immobilized monolithic enzyme microreactor also exhibited good practicability to complex human serum sample, in which the total of 45 peptides from human serum albumin (HSA) matched with sequence coverage of 75% were precisely identified. The successful application demonstrated the promising potential of the trypsin-immobilized capillary monolithic column as the IMER in high-throughput proteomic analysis.

: Based on the summary of the characteristics and existing problems of the instrumental analysis laboratory, the advantage of implementing virtual simulation technology was expounds. In addition, the outstanding performance of the virtual simulation laboratory teaching in dealing with special situations such as “ classes suspended but learning continues ” was introduced. Through questionnaires and interactive feedback, the learning situation of the students was evaluated. After pointing out the limitations of virtual simulation experiments, the teaching mode of combining online virtual simulation with offline classroom experiments was proposed, to promote the improvement of the quality of instrumental analysis laboratory teaching.

介绍一个由科研成果转化的分析化学综合设计性实验——纸基显色分析法测定白酒中硫离子的含量.硫离子与作为过氧化物模拟酶的四磺基酞菁铁(Fe(Ⅲ) TSPc)在酞菁环平面的轴向位置与中心铁原子配位,能进一步促进过氧链的断裂及高活性中间体高价铁氧正离子自由基的生成,导致3,3 ',5,5'-四甲基联苯胺(TMB)氧化产物在纸基上显色加深.利用颜色强度与硫离子含量的关系,可实现对硫离子简单、快速、实时、可靠的检测.本实验综合运用化学、光学、计算机软件等技术,对实验室硬件要求低,易于推广,且实验操作难度适中,内容新颖,综合性强,有利于培养学生实验知识灵活运用的能力.

该文阐述了对本科生进行系统的实验室安全教育的必要性和意义,介绍了福州大学化学实验教学中心“实验室安全与环保”课程的安排与教学内容.根据课程特点对教学方式进行了探索,并讨论了课程之外、渗透在本科生整个实验教学过程的安全教育措施和对策.

Hydrophilic magnetic mesoporous silica microspheres with core-shell structure were prepared via a facile approach and applied as an enrichment probe for low-abundance glycopeptides and glycans from complex biological samples. The prepared mesoporous silica microspheres modified with gluconamide groups at the interior surface of mesopore channels showed more prominent features with respect to high specific surface area (490 m(2)/g), narrow pore size distribution (2.5 nm), and high saturation magnetization (23.87 emu/g), endowing them with hydrophilicity and size-exclusion selectivity. Taking these advantages of the size-exclusion and the hydrophilic interactions, the hydrophilic mesoporous magnetic microspheres exhibited specificity for glycopeptides in a digest of horseradish peroxidase. The detection limit for horseradish peroxidase was 25 fmol. In addition, the hydrophilic mesoporous magnetic microspheres were further applied to the selective enrichment of N-linked glycans from a digest of human serum. The successful application demonstrates the potential of the hydrophilic mesoporous magnetic microspheres in glycoproteomic analysis.

A surface-enhanced Raman scattering (SERS) substrate with good flexibility and high water absorbing capacity is reported. It consists of a calcium alginate sponge incorporating gold nanoparticles. These are in close contact with the sponge without the need for amino or sulfhydryl modification. The substrate is capable of detecting the dyes crystal violet (CV) and malachite green (MG) in water directly and rapidly by immersing it into the liquid sample. Preconcentration and separation are not required. The dyes absorbed on the sponge can be detected without drying and thus the whole analytical process can be completed within 3 min. The results show that the lowest detectable concentrations are 0.1 and 0.25 μg⋅L−1 for CV and MG, respectively. This is lower than the minimum required performance limits set by the European Commission and the US EPA. Moreover, MG and CV can be simultaneously detected in liquid samples due to their different SERS bands (at 1216 and 1534 cm−1, respectively). It should be noted that the molecular structures of MG and CV are very similar. Therefore, the method has a large potential for determination of several analytes simultaneously even in complex sample metrics.

Iodine is one of essential trace elements. Deficiency of iodine and excess intake of iodine both can lead to thyroid diseases. Therefore, it is of great significance to develop a highly sensitive and selective method for the detection of iodine ions. Traditional analytical methods for iodine ions are usually involved in complex sample pretreatment and precision instruments, which are unfavorable for in-situ rapid detection. Fluorescent methods have been attracted great attentions due to their high sensitivity, high selectivity and easy operation. However, the present probes for iodine ions usually need complex organic syntheses and iodine ions are detected by means of coordination with heavy metal ions, which are unfavorable to promote the use of these methods. Fluorescent graphitic carbon nitride (g-C3N4) nanomaterial has attracted more attention due to the advatages of lowcost, easy preparation, high quantum yield, excellent photostability, and low toxicity. Furthermore, these nanomaterials can avoid complex synthesis for organic fluorophores or potential damage to environment for metal semiconductor quantum dots. These features make g-C3N4 nanomaterial an emerging fluorescent probe for the detection of metal ions. Recently, it was reported that Hg2+ ions could selectively and sensitively quench the fluorescence of g-C3N4 quantum dots (QDs). The addition of iodine ions could abstract the bound Hg2+ ions to form HgI2 complexes and restored the fluorescence of g-C3N4 QDs. Therefore, the fluorescent sensor for iodine ions could be developed. However, heavy metal ions (Hg2+) are also involved in this method, which limits its application. In this work, water-soluble g-C3N4 QDs with high fluorescence emission were prepared by using chemical oxidation of bulk g-C3N4 in nitric acid and hydro-thermal treatment. The maximal emission wavelength of g-C3N4 QDs located at 368 nm and did not change with the excitation wavelength, which indicates the size of g-C3N4 QDs is relatively uniform. There was a strong absorption peak at around 220 nm for iodine ions, which was overlapped with the fluorescent excitation spectrum of g-C3N4 QDs. On addition of iodine ions, the fluorescence of g-C3N4 QDs was quenched due to the inner filter effect. Therefore, a sensitive and selective fluorescent sensor for iodine ions was developed. Under the optimal conditions, there was a linear relationship between the fluorescence quenching (Delta F) of g-C3N4 QDs and the concentration (X, mu mol . L-1) of iodine ions over the range of 10 similar to 400 mu mol . L(-1)The linear equation is Delta F=0. 325 79X+6. 039 05 (R-2 = - 0.999 5). The limit of detection is 5. 0 mu mol . L-1. The detection of iodine ions can be completed by "mixing and testing" without the need of coordination with heavy metal ions. Thus, this sensor is rapid, environment-friendly, simple and convenient.

A sensitive and homogeneous electrochemical aptasensor was fabricated for the detection of mucin 1 (MUC1) by combining a well-designed DNA bulge-loop (L-DNA) structure with high-efficient exonuclease I (Exo I)-assisted target recycling amplification strategy. The L-DNA probe was constructed via the hybridization of the MUC1 aptamer and methylene blue (MB) labeled complementary DNA (cDNA) (cDNA-MB) and hence could not diffuse freely to the negatively charged ITO electrode surface due to the strong electrostatic repulsion, so small electrochemical signal was detected. The addition of MUC1 caused the dissociation of L-DNA structure due to the specificity between aptamer and MUC1. Then Exo I was implemented to digest the released cDNA-MB into mononucleotides and then produced short MB-labeled mononucleotides fragments (MB-MFs). As the MB-MFs contained few negative charges, it diffused easily to the negatively charged ITO electrode surface and resulted in the enhanced electrochemical signal. Meanwhile, the MUC1-aptamer complex was also specifically digested by Exo I, resulting in the liberation of MUC1 and hence realized the target recycling and then caused the amplification of the electrochemical signal. The enhanced electrochemical signal has a good linear relationship with logarithm of MUC1 concentration in the range of 1.0 pg mL-1-50 ng mL-1 with a limit of detection of 0.40 pg mL-1 (S/N = 3). Additionally, the fabricated aptasensor has been successfully applied to detect MUC1 in serum samples with satisfactory results and thereby it exhibits great potential in the practical application of clinical diagnosis.

In April 2016,the 1stChemistry Experiment Tournament of Fujian University Students was concluded at Fuzhou University.Through the analysis and exploration on the idea of setting questions, characteristics of the test,organization work and competition results,and at the same time,in view of the problems found,some suggestions for the reform of experimental teaching are put forward.

提出"以赛促改 、赛学结合 、守正创新 、科研引领"的化学实验教学改革新理念,对本科生的化学实验内容和实验模式进行大胆改革.将竞赛与传统实验教学相结合,充分利用科研团队的优势,积极推动科研反哺本科实验教学改革新举措,对实验教学内容进行优化,积极探索化学专业"一流"人才培养模式,取得了较显著的教学成果.

In this work, hierarchically mesoporous TiO2 spheres were successfully fabricated. The synthesis method could be simply described as adding Ti(SO4)(2) into the disperse phase of a conventional emulsion polymerization where emulgator was discovered to play an important role in the formation of the ingenious structure. When used as anode materials for lithium-ion batteries, it delivered a high capacity of 192 mA h g(-1) at 0.2 A g(-1) with the retention of 94.3% after 100 cycles, and a reversible capacity of 114 mA h g(-1) could be kept at 2 A g(-1) after 2000 cycles. At the same time, an excellent initial Coulombic efficiency (> 90%) and satisfactory rate performance were obtained.

Ultra performance liquid chromatography (UPLC), which is the new hotspots in the field, provides better separation and faster analysis than high performance liquid chromatography (HPLC) with the properties of particle sizes less than 2 μm and ultrahigh pressure systems(> 105 kPa). The ACQUITY Arc System, designed as the bridge between HPLC and UPLC method, is specifically engineered to respond to the needs of analytical scientists and can enable them to efficiently replicate or improve the established HPLC method, or easily transfer to UPLC performance just with the flip of a switch. The components, the usage and daily maintenance of Waters ACQUITY Arc liquid chromatographic system is introduced in detail. The article provides experience and direction for the beginners. The common faults and solutions of using the instrument are summarized, in order to ensure the accuracy and stability of the testing results and to extend the service life of the instrument.