在线净化加速溶剂萃取–气相色谱–质谱法测定土壤中11种半挥发性有机物

采用加速溶剂萃取法对样品进行在线净化和萃取,气相色谱–质谱法测定土壤中11种半挥发性有机物.考察了净化条件、萃取剂、浓缩条件等因素对土壤中11种半挥发性有机物测定的影响,分析了在线净化和离线净化的差异以及在线净化的优势.以弗罗里硅土和石墨化碳黑为净化剂,石英砂为分散剂,土壤样品经快速溶剂萃取仪在线净化萃取,浓缩后采用气...     

分散固相萃取净化/高效液相色谱-串联质谱法测定水产品中的5种硝基咪唑类药物残留

建立了水产品中5种硝基咪唑类药物的高效液相色谱-串联质谱检测方法。样品经含0.1%氨水乙腈提取,加无水硫酸钠、C18-N以及NH2-PSA净化剂后涡旋振荡对样品进行净化,以Merck Chromolith Performance RP-18e(4.6 mm×100 mm)色谱柱分离,甲醇和0.1%甲酸水溶液为流动相梯度洗脱,正离子模式电喷雾电离,配合多反应离子扫描(MRM)定性定量分析目标化合物。考察了提取剂中氨水和净化剂的用量对加标回收率的影响,在优化实验条件下,5种硝基咪唑类药物在20~500μg/L范围内线性关系良好,r2≥0.998 9;3个加标水平下的方法回收率为77.2%~94.8%;定量下限为0.7~2.0μg/kg。该方法快速、简单、准确,适用于水产品中5种硝基咪唑类药物残留的检测。     

超高效液相色谱-串联质谱法检测花生中36种农药及其代谢物残留

建立了花生中36种农药及其代谢物残留的超高效液相色谱-串联质谱(UHPLC-MS/MS)快速检测技术。采用乙腈提取,增强型脂质去除净化剂(EMR-Lipid)净化,正离子多反应监测(MRM)模式测定。结果表明,所有农药的线性相关系数均大于0.994,在0.005,0.01,0.10 mg/kg 3个加标水平下,36种农药的平均回收率为70.4%~119%,相对标准偏差(RSDs)为1.3%~19.4%,方法的定量下限为0.002 5~0.05 mg/kg。该方法简便、快速,灵敏度高、净化效果好,适用于花生中农药多残留的快速检测分析。     

用玫瑰茎制备多孔炭及其水溶液中对铬(Ⅵ)的吸附研究

以玫瑰茎为原料,制备了多孔炭材料,并将其应用于含Cr(VI)的污染水净化。研究结果表明,用玫瑰茎制备的炭材料具有多孔结构,且具有较高的比表面积。应用EDS分析和傅立叶红外光谱分析进一步证明了该炭材料具有含氧官能团活性位点,是一种潜在的吸附材料。将其应用于含Cr(VI)污染水净化研究结果表明,净化过程符合准二级动力学,最大吸附量可达344.83 mg/g,明显高于市售污水净化用炭材料Norit CGP(最大吸附量305.81 mg/g)。这种炭材料有望成为性能优异的含Cr(VI)污水的净化剂。     

风化煤处理含金属离子废水的研究 Ⅰ.风化煤对金属离子的吸附

风化煤是一种良好的金属离子吸附剂。它对不同金属离子的净化顺序为:Pb~(2 )>Cd~(2 )>Cu~(2 )>Zn~(2 )>Ni~(2 )。钙型净化剂的吸附容量比氢型净化剂大一倍。本文还讨论了风化煤吸附金属离子的影响因素。废水中其它共存的阳离子对金属离子的吸附有干扰作用,其中H~ 的影响十分明显,而二价金属阳离子的影响比一价金属的大。     

分散固相萃取-超高效液相色谱-串联质谱法测定禽蛋中氟虫腈及其代谢产物

建立了分散固相萃取-超高效液相色谱-串联质谱检测禽蛋中氟虫腈及其代谢产物氟甲腈、氟虫腈硫醚和氟虫腈砜的方法。样品用含1%(体积分数)乙酸的乙腈提取后,加无水硫酸钠、十八烷基键合硅胶(C18-N)及氨基-丙基乙二胺(NH2-PSA)3种净化剂,旋涡振荡,对样品进行净化。以Shim-pack GIST C18色谱柱(50 mm×2.1 mm,2μm)进行分离,以甲醇和1 mmol/L乙酸铵水溶液为流动相进行梯度洗脱,在电喷雾离子源负离子模式和多反应检测(MRM)模式下进行定性定量分析。考察了净化剂中无水硫酸钠、C18-N和NH2-PSA的用量对加标回收率的影响,优化了实验条件。结果表明:4种化合物在0.4~100μg/L范围内线性关系良好,相关系数r2≥0.998 9;回收率为95.09%~103.26%;定量限为0.2μg/kg。该方法前处理简单,回收率高,重复性好,可作为禽蛋中氟虫腈及其代谢产物的有效检测方法。     

新型QuEChERS结合固相萃取-高效液相色谱法测定水产品中6种麻醉剂

建立了新型QuEChERS结合固相萃取-高效液相色谱法同时测定水产品中普鲁卡因、利多卡因、布比卡因、3-氨基苯甲酸乙酯甲基磺酸盐(MS-222)、苯佐卡因、丁卡因等6种麻醉剂的检测方法。样品用磷酸盐缓冲液(pH4.4)-乙腈溶液提取,增强型脂质去除净化剂(EMR-Lipid)净化,再经HLB固相萃取柱净化,高效液相色谱-二极管阵列检测器测定,外标法定量。结果表明,6种卡因类麻醉剂在0.20~10.00μg/mL范围内呈良好的线性关系,相关系数(R2)均大于0.9998;方法检出限(LODs)均为0.06 mg/kg,方法定量限(LOQs)均为0.20 mg/kg。3种不同添加水平下的样品加标平均回收率为71.8%~95.3%,相对标准偏差(RSDs)为2.3%~8.1%。     

猪骨基多孔炭对六价铬吸附性能的分析

以废弃的猪骨为原料制备的多孔炭作为吸附剂,分析了其对含Cr工业废水的净化作用,并对其吸附机理进行探讨。结果表明,吸附体系的pH、吸附时间、Cr(Ⅵ)初始浓度对多孔炭吸附Cr(Ⅵ)的能力影响较大,多孔炭材料的比表面积对其吸附水溶液中的Cr(Ⅵ)起决定性作用。该吸附过程符合二级动力学吸附模型,并且可用Langmuir吸附等温线来描述。所以猪骨基多孔炭有望成为含Cr(Ⅵ)废水的良好净化剂。     

气相色谱-串联质谱技术分析烟草中的132种农药残留

利用气相色谱-串联质谱(GC-MS/MS)检测技术,建立了检测烟草中的132种农药残留的高灵敏度方法。分析过程中考察了不同萃取溶剂、不同缓冲盐体系、不同净化剂对目标物回收率的影响。最终确定烟草样品以乙腈进行提取,以N-丙基乙二胺(PSA)与碳18(C18E)的混合净化剂进行净化,氮气吹近干后用正己烷-丙酮(9:1, v/v)复溶,过有机滤膜后进行GC-MS/MS测定,内标法定量。132种农药在20～2000 μg/kg之间线性关系良好(r2 ＞0.99);所有农药的方法定量限(LOQ, S/N=10)均低于20 μg/kg;在50、200、500 μg/kg的加标水平下,除灭蚁灵及六氯苯回收率稍低外,其他农药的平均回收率为68.10%～123.15%,相对标准偏差(RSD)为1.79%～19.88%。对国际烟草科学研究合作中心(CORESTA)2012年共同实验的烟草样品进行检测,对比本方法与已有的标准方法,其结果一致性较好。该方法准确、可靠,灵敏度好,适用于烟草中132种农药残留的快速筛查与定性、定量分析。     

基于真菌毒素污染差异的液相色谱-串联质谱法鉴别板栗粉中掺假小麦粉

建立了分散固相萃取-超快速液相色谱-串联质谱法同时测定板栗粉和小麦粉中43种真菌毒素的方法,对48份板栗粉和80份小麦粉样品的污染状况进行调查,筛选出5种专属于小麦粉的标志性真菌毒素.样品采用84％(v/v)乙腈水溶液提取,提取液采用C18结合增强型脂质去除净化剂(EMR-Lipid)净化,采用响应曲面-中心组合设计优...     

离子色谱法测定净水产品中F-、Cl-、NO-2、No-3、HPO2-4和SO2-4

建立了离子色谱法测定净水产品中的F<'->、Cl<'->、NO<'-><,2>、No<'-><,3>、HPO<'2-><,4>和SO<'2-><,4>6种阴离子.根据净水产品的类型分别选择配制水浸提和直接净化配制水两种方法处理样品,选用IonPac As9-HC色谱柱(250 mm×4 mm),8.0 mm0L/L N...     

Bilayer rGO-Based Photothermal Evaporator for Efficient Solar-Driven Water Purification[]**

Interfacial evaporation has emerged as a promising approach to produce freshwater. However, an urgent concern is that, due to the illegal discharge of industrial wastewater, most water bodies are polluted by trace volatile organic compounds (VOCs), which are easily volatilized and enriched in the collected water during the interfacial evaporation process. Herein, a bilayer photothermal evaporator was reasonably designed for contaminated water purification. The bottom hydrophilic rGO-sodium alginate (SA) sheets purposefully disintegrate water transport channels, thus quickly removing VOCs through physical adsorption. The rGO-SA-TiO₂ upper layer sufficiently absorbs incident light and therefore persistently generates reactive oxidizing species to degrade upward VOCs. Notably, the oriented microchannels inside the evaporator allow sustained light reflections to improve the utilization of solar energy. The evaporation rate can reach 1.63 kg m⁻² h⁻¹ with a considerably high VOC removal efficiency of up to 96 %. Such an integrated bilayer evaporator provides an effective strategy to obtain clean water via solar distillation.     

Removal of Multiple Contaminants from Water by Polyoxometalate Supported Ionic Liquid Phases (POM‐SILPs)

The simultaneous removal of organic, inorganic, and microbial contaminants from water by one material offers significant advantages when fast, facile, and robust water purification is required. Herein, we present a supported ionic liquid phase (SILP) composite where each component targets a specific type of water contaminant: a polyoxometalate‐ionic liquid (POM‐IL) is immobilized on porous silica, giving the heterogeneous SILP. The water‐insoluble POM‐IL is composed of antimicrobial alkylammonium cations and lacunary polyoxometalate anions with heavy‐metal binding sites. The lipophilicity of the POM‐IL enables adsorption of organic contaminants. The silica support can bind radionuclides. Using the POM‐SILP in filtration columns enables one‐step multi‐contaminant water purification. The results show how multi‐functional POM‐SILPs can be designed for advanced purification applications.     

Water Purification and Microplastics Removal Using Magnetic Polyoxometalate‐Supported Ionic Liquid Phases (magPOM‐SILPs)

Filtration is an established water‐purification technology. However, due to low flow rates, the filtration of large volumes of water is often not practical. Herein, we report an alternative purification approach in which a magnetic nanoparticle composite is used to remove organic, inorganic, microbial, and microplastics pollutants from water. The composite is based on a polyoxometalate ionic liquid (POM‐IL) adsorbed onto magnetic microporous core–shell Fe₂O₃/SiO₂ particles, giving a magnetic POM‐supported ionic liquid phase (magPOM‐SILP). Efficient, often quantitative removal of several typical surface water pollutants is reported together with facile removal of the particles using a permanent magnet. Tuning of the composite components could lead to new materials for centralized and decentralized water purification systems.     

Continuous flow microfluidic device for cell separation, cell lysis and DNA purification

A novel integrated microfluidic device that consisted of microfilter, micromixer, micropillar array, microweir, microchannel, microchamber, and porous matrix was developed to perform sample pre-treatment of whole blood. Cell separation, cell lysis and DNA purification were performed in this miniaturized device during a continuous flow process. Crossflow filtration was proposed to separate blood cells, which could successfully avoid clogging or jamming. After blood cells were lyzed in guanidine buffer, genomic DNA in white blood cells was released and adsorbed on porous matrix fabricated by anodizing silicon in HF/ethanol electrolyte. The flow process of solutions was simulated and optimized. The anodization process of porous matrix was also studied. Using the continuous flow procedure of cell separation, cell lysis and DNA adsorption, average 35.7 ng genomic DNA was purified on the integrated microfluidic device from 1 μL rat whole blood. Comparison with a commercial centrifuge method, the miniaturized device can extract comparable amounts of PCR-amplifiable DNA in 50 min. The greatest potential of this integrated miniaturized device was illustrated by pre-treating whole blood sample, where eventual integration of sample preparation, PCR, and separation on a single device could potentially enable complete detection in the fields of point-of-care genetic analysis, environmental testing, and biological warfare agent detection.     

Isolation and Purification of Fucoxanthin from Brown Seaweed Sargassum horneri Using Open ODS Column Chromatography and Ethanol Precipitation

As an abundant marine xanthophyll, fucoxanthin (FX) exhibits a broad range of biological activities. The preparation of high-purity FX is in great demand, however, most of the available methods require organic solvents which cannot meet the green chemistry standard. In the present study, a simple and efficient purification approach for the purification of FX from the brown seaweed Sargassum horneri was carried out. The FX-rich ethanol extract was isolated by octadecylsilyl (ODS) column chromatography using ethanol–water solvent as a gradient eluent. The overwhelming majority of FX was successfully eluted by the ethanol–water mixture (9:1, v/v), with a recovery rate of 95.36%. A parametric study was performed to optimize the aqueous ethanol precipitation process by investigating the effects on the purity and recovery of FX. Under the optimal conditions, the purity of FX was 91.07%, and the recovery rate was 74.98%. Collectively, the eco-friendly method was cost-efficient for the purification of FX. The developed method provides a potential approach for the large-scale production of fucoxanthin from the brown seaweed Sargassum horneri.     

CsPbI3钙钛矿量子点的精细纯化及其高效发光二极管的研究

钙钛矿量子点发光二极管(QLEDs)因其色纯度高、颜色控制精准、色域广以及溶液可加工等特点,在显示和照明等领域有着极大的应用前景.针对红光钙钛矿CsPbI3量子点纯化过程中相变和表面配体损失造成的荧光退化问题,本工作发展了一种甲苯和乙酸乙酯协同的混合溶剂纯化策略,能够避免纯化过程中的相变问题,获得了纯立方相的CsPbI...     

Polymeric materials for solar water purification

Solar-based desalination or water purification is regarded as one of the promising solutions to global water scarcity as the only energy input is abundant and sustainable solar light. Interfacial solar vapor generation (SVG), which converts natural sunlight into clean water vapor, has attracted extensive research interests due to its high-energy utilization efficiency and simple implementation. With tunable molecular structures and tailorable physical properties, polymers have demonstrated great potential as candidate materials for solar evaporators. In this review, we summarize the recent progress on polymer materials for solar-powered water purification. First, we present functional polymers with highly tunable molecular composition and morphology as high-efficiency solar absorbers. Next, the recent development of various polymeric materials and structural engineering strategies for adequate water supply and efficient thermal management are discussed, along with their excellent desalination and purification performance. Last, we outline the challenges and future directions on the further development of polymer materials for solar water purification technologies.     

The Role and Efficiency of Ammonium Sulphate Precipitation in Purification Process of Papain Crude Extract

It has been common to do fractionation (for example using ammonium sulphate as a precipitating agent) before doing a more sophisticated method for purification of a protein. The logic behind this is easy to understand, but in fact, the precipitation step often causes severe loss in yield and activity of the protein, making the whole purification effort too costly. In this work we evaluated the specific activity (thus, purification factor) and total activity (yield) during the purification process of papain from a crude extract using ion exchange chromatography (IEC), with and without prior fractionation using ammonium sulphate. Detail assays in each step were recorded and SDS-PAGE was also done to reveal the protein profile of the purification products.     

The distinctive separation attributes of mixed-mode resins and their application in monoclonal antibody downstream purification process

Increased upstream productivity and the continuous pressure to deliver high quality drug product have resulted in the development of new separation technologies and platform strategies for downstream purification processes of monoclonal antibodies (mAb). In this study, the separation attributes of three mixed-mode resins, Mercapto-Ethyl-Pyridine (MEP) hydrophobic charge induction resin, Capto adhere multi-modal anion exchange resin, and ceramic hydroxyapatite/fluoroapatite (CHT/CFT) resins, were investigated to define their roles in monoclonal antibody purification processes. We demonstrated that the multi-modal nature of ligands on mixed-mode resins allows the separation resolution to be honed, either through a single dominant mechanism or through mix-modal balanced purification strategies. In addition, the three mixed-mode resins present different purification powers for different types of impurities. We also demonstrated that besides enhancing chromatography separation and improve product quality, especially for high molecular weight (HMW) aggregate reduction, mixed-mode resins can also help to improve process efficiency in industrial-scale mAb drug manufacturing. Our results underscore the importance of selecting appropriate chromatography resins during DSP design to obtain the best overall process outcome.