基于显微光谱法的双壳类海洋生物中微塑料的检测方法研究

建立准确、高效的微塑料分析方法是研究微塑料在环境中的迁移、转化、归趋和生态毒理效应的前提.该研究系统优化了4种消解条件和滤膜种类,建立了用显微红外和拉曼光谱检测海产品中微塑料的方法,确定使用氢氧化钾在40℃下消解36 h,并用混合纤维素滤膜过滤的前处理方法.结果显示,大颗粒微塑料可使用显微红外全反射(ATR)、成像模式...     

土壤样品中微塑料的分析方法研究进展

微塑料作为一种新型污染物,因其粒径小、难以降解、本身含有多种污染物、且易吸附疏水性有机污染物和重金属等产生复合污染,已成为国内外学者研究的热点问题.微塑料广泛存在于土壤环境中,进入土壤中的微塑料会影响土壤理化性质,同时影响土壤动物生长、植物生长和微生物活动等,并且,微塑料会在土壤中发生迁移或沿食物链传递从而对人类健康构...     

More Convenient and Suitable Methods for Sphere Tensiometry

Two new convenient and suitable gravimetric methods of measuring surface and interfacial tensions of liquids and contact angles of liquids on a spherical surface by pulling a sphere through the interface were examined. First, the accuracy of numerical integration was increased. Second, two methods which treat the experimental data were presented and compared. Both methods can be used for determination of the contact angle and interfacial tension at the same time.     

Selection of A Suitable Solvent System for the Separation and Quantitation of Histamine

Abstract

The suitability of 79:21, 85:15 and, 90:10 of phosphate buffer: 50% methanol, as mobile phases, to separate and quantitate histamine in small plasma volume (<300 μl) was investigated by using a Dionex BioLC System coupled to a pulsed amperometric detector. Also, special attempts were made to reduce the time of analysis of each sample. Methylhistamine was used as an internal standard. the best results were obtained with the 79:21 mobile phase with concommittant reduction in analysis time from the current 1 sample per 90 min to 5 samples per 60 min suggesting that the method is suitable and cost effective.     

Analytical Methods for Speciation of Organotins in the Environment

The growing awareness over the environmental fate of organotin compounds is reflected in the large number of analytical methods developed for their separation. Organotin compounds have varying degrees of toxicological properties, depending on the nature and number of alkyl groups bonded to the tin atom. Most of the analytical speciation methods applied to actual environmental media have involved prior derivatization to transform organotin compounds into volatile hydrophobic analytes amenable to separation and identification by gas chromatography coupled to a sensitive and selective tin-detector. Evidence exists that members of the same homologous series are related by environmental degradation pathways. Chemical treatment prior to analysis, or high temperatures associated with gas chromatography separation, may alter the relative amounts of organotins in samples and blur the true environment picture. To avoid species redistribution that may occur during derivatization or gas speciation analysis, methods based on liquid chromatography and supercritical fluid chromatography have been investigated. This review documents analytical methods for determination of tin and speciation of organotin compounds, in the hope that it will be of value to those interested in initiating a programme for assessing the impact of such species on the environment.     

Labeling Microplastics with Fluorescent Dyes for Detection,Recovery, and Degradation Experiments

Staining microplastics (MPs) for fluorescence detection has been widely applied in MP analyses. However, there is a lack of standardized staining procedures and conditions, with different researchers using different dye concentrations, solvents, incubation times, and staining temperatures. Moreover, with the limited types and morphologies of commercially available MPs, a simple and optimized approach to making fluorescent MPs is needed. In this study, 4 different textile dyes, along with Nile red dye for comparison, are used to stain 17 different polymers under various conditions to optimize the staining procedure. The MPs included both virgin and naturally weathered polymers with different sizes and shapes (e.g., fragments, fibers, foams, pellets, beads). We show that the strongest fluorescence intensity occurred with aqueous staining at 70 °C for 3 h with a dye concentration of 5 mg/mL, 55 mg/mL, and 2 µg/mL for iDye dyes, Rit dyes, and Nile red, respectively. Red fluorescent signals are stronger and thus preferred over green ones. The staining procedure did not significantly alter the surface, mass, and chemical characteristics of the particles, based on FTIR and stereomicroscopy. Stained MPs were spiked into freshwater, saltwater, a sediment slurry, and wastewater-activated sludge; even after several days, the recovered particles are still strongly fluoresced. The approach described herein for producing customized fluorescent MPs and quantifying MPs in laboratory-controlled experiments is both straightforward and simple.     

Symmetry-adapted Localized Wannier Functions Suitable for Periodic Local Correlation Methods

A scheme for the a posteriori symmetrization of a set of localized Wannier functions is presented and illustrated with some examples. The method has been implemented in the periodic code CRYSTAL using the LCAO approach and it is shown that they can be useful in the computational implementation of periodic local correlation methods. The resulting functions feature very accurate symmetry correspondences without a significant loss of the original localization properties.     

环境中纳米材料的分离与分析方法

随着纳米科技的发展和纳米材料的广泛应用,进入环境中的纳米材料必将随之增加。由于纳米材料可能对生态环境和人体健康带来潜在的危害,了解环境中纳米材料的浓度水平和行为有助于正确认识和评价纳米材料的环境风险,并做出相应的防治对策。然而,纳米材料所具有的诸多特殊性质直接影响它们的环境行为和生态毒性,因此,环境中纳米材料的分析不仅包括浓度的定量测定,还包括对其组成、粒径和表面电荷等性质的表征,是一项具有挑战性的工作。本文综述了近年来关于环境纳米材料分离、表征及检测的相关手段和方法,重点包括场流分离、色谱分离和电泳分离在纳米材料分离以及显微和谱学技术在纳米材料分析中的应用;提出了一些思考和展望,希望能够增进对环境中纳米材料分离和分析方法的了解,有助于纳米材料环境分析方法的建立和推动纳米材料环境行为和生态毒理研究的进一步规范。     

端粒酶检测新方法研究进展

端粒酶是一种核蛋白逆转录酶,能以自身的RNA为模板添加重复序列(TTAGGG)n至染色体末端,稳定端粒长度。端粒酶在85%～90%的癌细胞中处于激活状态,已经引起了人们的广泛关注,成为肿瘤诊断和临床治疗的重要突破口。因此,准确、高效地测定端粒酶活性具有重要意义。近年来,许多灵敏、准确的体外或原位检测技术在端粒酶活性检测方面得到了发展。该文综述了近年来端粒酶活性检测的最新进展,并对其发展趋势进行了展望。     

鹅膏毒肽检测方法的研究进展

一直以来毒蘑菇中毒在全球范围内频发,成为最常见的食物中毒事件之一,也是食物中毒致死的最主要原因.毒蘑菇中含量最高、致死性最强的毒素为鹅膏毒肽.因此,鹅膏毒素准确快捷的检测对鉴别中毒源、患者后续治疗及预防有着重要意义.目前,鹅膏毒肽的常用检测方法包括色谱-质谱联用技术以及一些基于免疫识别和特殊化学结构的检测技术.而不断开...     

环境中氯苯类化合物的分析研究进展

氯苯类化合物（邻二氯苯、对二氯苯、间二氯苯、三氯苯、氯甲苯、二氯甲苯和三氯甲苯等）是环境中需要重点监测的致癌污染物,文章介绍了近年来国内外环境中氯苯类化合物的分析研究进展。主要的分析测定方法有：普通气相色谱法、固相微萃取．毛细管气相色谱法、吹扫捕集．气相色谱法、顶空气相色谱法、高效液相色谱法、光度法和红外光谱法等。分析测定方法和结果对评价环境污染具有重要意义。     

基于石墨烯的真菌毒素检测方法研究进展

近年来,二维纳米材料石墨烯成为生物毒素检测领域的研究热点。该文对真菌毒素的检测现状作了简要介绍,对基于该类纳米材料的真菌毒素检测技术研究进行综述,并展望了真菌毒素检测技术发展的新趋势。     

Microplastics occurrence and fate in the environment

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In situ Detection of Microplastics: Single Microparticle‐electrode Impacts

Particle‐impact electrochemistry is employed to study spherical polyethylene microparticles suspended in an aqueous solution. This electrochemical method detects polyethylene microparticles impacting on a carbon fiber electrode generating a transient current response or “spike”. We interpret the physio‐chemical origin of the spikes and accurately identify particle size distributions and concentrations for microparticles of sizes 1–10 μm.     

Simply Applicable Method for Microplastics Determination in Environmental Samples

Microplastics (MPs) have gained significant attention in the last two decades and have been widely researched in the marine environment. There are, however, less studies on their presence, routes of entry, and impacts on the biota in the soil environment. One of the main issues in the study of MPs is a lack of standardized methods for their identification in environmental samples. Currently the most commonly used techniques are thermal desorption gas chromatography–mass spectrometry (GC–MS) methods and pyrolysis followed by GC–MS. In this study, headspace-solid phase microextraction followed by GC–MS is proposed as a simple and widely applicable method for the determination of commonly present polymer MPs (polyethylene terephthalate, polystyrene, polyvinyl chloride, polyethylene, and polypropylene) in environmental samples, for analytical laboratories with basic equipment worldwide. The proposed method is based on the identification of compounds, which are formed during the well-controlled melting process of specific coarse (1–5 mm) and fine fraction (1 mm–100 μm) MPs. The method was upgraded for the identification of individual polymer type in blends and in complex environmental matrices (soil and algae biomass). The successful application of the method in complex matrices makes it especially suitable for widescale use.     

血指印检测研究进展

犯罪现场血指印的发现和提取在案件侦破中起着非常重要的作用,是最有效的个人身份鉴定手段之一。血指印检测方法依据反应原理的不同分为化学方法、物理方法、生物染色和光学方法等4类。本文重点综述了血指印的检测技术、常用试剂及其优缺点,并展望了血指印检测方法的方向和前景。     

食品中铝检测方法研究进展

介绍了食品中铝的来源,并综述了近十年中食品中铝测定方法的研究进展,包括电感耦合等离子体原子发射光谱法、电感耦合等离子体质谱法、石墨炉原子吸收光谱法、电化学分析法以及分光光度法等方法(引用文献75篇)。     

紫外光离子源-高场不对称波形离子迁移谱检测环境中挥发性有机物

本研究采用紫外光离子源-高场不对称波形离子迁移谱(UV-FAIMS)快速检测环境中挥发性有机物.选取苯和对二甲苯为研究对象,并分析了分离电压、流速等因素对其分离识别的影响.实验结果表明:当分离电压值为0～1200 V时,苯和对二甲苯信号强度逐渐降低,而特征补偿电压值却逐渐增加.实验选取分离电压值为900 V,当载气流速为0～240 L/h时,苯和对二甲苯的特征离子峰信号强度逐渐增加,当载气流速为0～120 L/h时,苯和对二甲苯团簇峰信号强度增加,当载气流速为120～240 L/h时,苯的团簇峰信号强度增加,而对二甲苯的团簇峰信号强度降低.此外,对样品浓度、信号强度与噪声的比值进行探讨,获得UV-FAIMS检测苯的检测限为0.011mg/m3.     

非洲猪瘟病毒检测方法的研究进展

非洲猪瘟是一种影响各个品种与年龄段猪的毁灭性传染病,其特征包括高烧,皮肤发绀,淋巴严重出血,死亡率接近100％,被世界动物卫生组织列为必须及时通报的动物疫病,而我国也将其列为主要的外来动物疾病.自20世纪90年代被报道流行于非洲撒哈拉沙漠以南的国家以来,非洲猪瘟逐步流行于欧洲、南美、俄罗斯高加索地区,并在全球各地爆发,...     

K金饰品中金含量的检测方法比对

目前实验室对金首饰金含量的主要检测方法为火试金法、X射线荧光光谱（XRF）法和电感耦合等离子体-原子发射光谱（ICP-AES）法.当测试结果出现争议时,国家标准GB 11887-2012中以火试金法作为仲裁方法.采用上述3种不同的金含量测试方法分别对14K、18K和22K饰品的金含量进行测定,并对3种方法检测结果进行比对.结果发现,在3种方法均可满足样品分析对准确度的要求时,以火试金法为基准,XRF法与ICP-AES法对同纯度的金首饰检测结果的相对误差差异较大,XRF法的结果可满足检测要求,而ICP-AES法的结果无法满足检测要求.其中,XRF法的相对误差为0.05%~0.77%,ICP-AES法的相对误差为1.24%~3.89%.从结果来看,低纯度的K金饰品使用XRF法的检测结果要更接近于火试金法.