Lignin and Lignin-Derived Compounds for Wood Applications—A Review

Improving the environmental performance of resins in wood treatment by using renewable chemicals has been a topic of interest for a long time. At the same time, lignin, the second most abundant biomass on earth, is produced in large scale as a side product and mainly used energetically. The use of lignin in wood adhesives or for wood modification has received a lot of scientific attention. Despite this, there are only few lignin-derived wood products commercially available. This review provides a summary of the research on lignin application in wood adhesives, as well as for wood modification. The research on the use of uncleaved lignin and of cleavage products of lignin is reviewed. Finally, the current state of the art of commercialization of lignin-derived wood products is presented.     

Determination of volatile organic compounds in human breath for Helicobacter pylori detection by SPME-GC/MS

Helicobacter pylori living in the human stomach release volatile organic compounds (VOCs) that can be detected in expired air. The aim of the study was the application of breath analysis for bacteria detection. It was accomplished by determination of VOCs characteristic for patients with H. pylori and the analysis of gases released by bacteria in suspension. Solid-phase microextraction was applied as a selective technique for preconcentration and isolation of analytes. Gas chromatography coupled with mass spectrometry was used for the separation and identification of volatile analytes in breath samples and bacterial headspace. For data calculation and processing, discriminant and factor analyses were used. Endogenous substances such as isobutane, 2-butanone and ethyl acetate were detected in the breath of persons with H. pylori in the stomach and in the gaseous mixture released by the bacteria strain but they were not identified in the breath of healthy volunteers. The canonical analysis of discrimination functions showed a strong difference between the three examined groups. Knowledge of substances emitted by H. pylori with the application of an optimized breath analysis method might become a very useful tool for noninvasive detection of this bacterium.     

Recent Advances and Prospects in Design of Hydrogen Permeation Barrier Materials for Energy Applications—A Review

The hydrogen infrastructure involves hydrogen production, storage and delivery for utilization with clean energy applications. Hydrogen ingress into structural materials can be detrimental due to corrosion and embrittlement. To enable safe operation in applications that need protection from hydrogen isotopes, this review article summarizes most recent advances in materials design and performance characterization of barrier coatings to prevent hydrogen isotopes’ absorption ingress and permeation. Barriers are crucial to prevent hydride formation and unwanted hydrogen effects to increase safety, materials’ lifetime and reduce cost for applications within nuclear and renewable energy. The coating may be applied on a material that requires protection from hydrogen pick-up, transport and hydride formation in hydrogen storage containers, in pipelines, spent nuclear fuel storage or in nuclear reactors. While existing, commercial coatings that have been much in use may be satisfactory for various applications, it is desirable to evaluate whether alternative coating concepts can provide a greater resistance to hydrogen isotope permeation along with other improved properties, such as mechanical strength and thermal resistance. The information presented here is focusing on recent findings within the past 5–7 years of promising hydrogen barriers including oxides, nitrides, carbon, carbide, MAX-phases and metals and their mechanical strength, hydrogen pick-up, radiation resistance and coating manufacturing techniques. A brief introduction to hydrogen permeation is provided. Knowledge gaps were identified to provide guidance for material’s research prospects.     

Development of a Water Matrix Certified Reference Material for Volatile Organic Compounds Analysis in Water

Water matrix certified reference material (MCRM) of volatile organic compounds (VOCs) is used to provide quality assurance and quality control (QA/QC) during the analysis of VOCs in water. In this research, a water MCRM of 28 VOCs was developed using a “reconstitution” approach by adding VOCs spiking, methanol solution into pure water immediately prior to analysis. The VOCs spiking solution was prepared gravimetrically by dividing 28 VOCs into seven groups, then based on ISO Guide 35, using gas chromatography-mass spectrometry (GC-MS) to investigate the homogeneity and long-term stability. The studies of homogeneity and long-term stability indicated that the batch of VOCs spiking solution was homogeneous and stable at room temperature for at least 15 months. Moreover, the water MCRM of 28 VOCs was certified by a network of nine competent laboratories, and the certified values and expanded uncertainties of 28 VOCs ranged from 6.2 to 17 μg/L and 0.5 to 5.3 μg/L, respectively.     

饮用水中挥发性有机物(VOCs)的GC-MS分析

用顶空－毛细管气相色谱－质谱联用仪测定了北京主要区域的自来水,北京目前市场销售的瓶装饮用水（包括天然矿泉水,纯净水等）中２３种挥发性有机物（ＶＯＣｓ）（包括有机氯化物,有机溴代物及苯系物等）的浓度,并与其它城市（如天津,上海,兰州等地）的自来水中ＶＯＣｓ的浓度进行了比较,结果表明北京市区内自来水及大多数市售瓶瓶饮用水中ＶＯＣｓ含量很低。     

水性涂料中挥发性有机化合物的气相色谱-质谱法测定

建立了内墙涂料中24种挥发性有机化合物(VOCs)的GC-MS检测方法,重点研究了现有检测方法分离度差和回收率低的问题,采用无水硫酸钠净化、二氯甲烷超声和膜过滤提取体系,改善了各种化合物的回收率,特别是提高了二元醇类化合物的回收率,优化后的实验条件下,样品的加标回收率为70%~94%,相对标准偏差不大于6.8%,检出限为3.1~10.6 mg/L。在30~300 mg/L范围内,方法的线性关系良好,相关系数大于0.99。该方法简便、快速、灵敏、精密度好,完全满足进出口水性涂料中常见的24种挥发性有机化合物的检测要求。     

Droplet Microfluidics—A Tool for Single‐Cell Analysis

Droplet microfluidics allows the isolation of single cells and reagents in monodisperse picoliter liquid capsules and manipulations at a throughput of thousands of droplets per second. These qualities allow many of the challenges in single‐cell analysis to be overcome. Monodispersity enables quantitative control of solute concentrations, while encapsulation in droplets provides an isolated compartment for the single cell and its immediate environment. The high throughput allows the processing and analysis of the tens of thousands to millions of cells that must be analyzed to accurately describe a heterogeneous cell population so as to find rare cell types or access sufficient biological space to find hits in a directed evolution experiment. The low volumes of the droplets make very large screens economically viable. This Review gives an overview of the current state of single‐cell analysis involving droplet microfluidics and offers examples where droplet microfluidics can further biological understanding.     

Searching for Potential Markers of Glomerulopathy in Urine by HS-SPME-GC×GC TOFMS

Volatile organic compounds (VOCs) exiting in urine are potential biomarkers of chronic kidney diseases. Headspace solid phase microextraction (HS-SPME) was applied for extraction VOCs over the urine samples. Volatile metabolites were separated and identified by means of two-dimensional gas chromatography and time of flight mass spectrometry (GC × GC TOF MS). Patients with glomerular diseases (n = 27) and healthy controls (n = 20) were recruited in the study. Different VOCs profiles were obtained from patients and control. Developed methodology offers the opportunity to examine the metabolic profile associated with glomerulopathy. Four compounds found in elevated amounts in the patients group, i.e., methyl hexadecanoate; 9-hexadecen-1-ol; 6,10-dimethyl-5,9-undecadien-2-one and 2-pentanone were proposed as markers of glomerular diseases.     

Biomaterials Based on Chitosan and Its Derivatives and Their Potential in Tissue Engineering and Other Biomedical Applications—A Review

In the times of dynamically developing regenerative medicine, more and more attention is focused on the use of natural polymers. This is due to their high biocompatibility and biodegradability without the production of toxic compounds, which means that they do not hurt humans and the natural environment. Chitosan and its derivatives are polymers made most often from the shells of crustaceans and are biodegradable and biocompatible. Some of them have antibacterial or metal-chelating properties. This review article presents the development of biomaterials based on chitosan and its derivatives used in regenerative medicine, such as a dressing or graft of soft tissues or bones. Various examples of preparations based on chitosan and its derivatives in the form of gels, films, and 3D structures and crosslinking products with another polymer are discussed herein. This article summarizes the latest advances in medicine with the use of biomaterials based on chitosan and its derivatives and provides perspectives on future research activities.     

静态顶空/气相色谱-质谱法同时测定化妆品中22种有毒挥发性有机溶剂残留

以2015版《化妆品安全技术规范》中规定的常见禁用及限用有毒挥发性有机溶剂为研究对象,建立了静态顶空/气相色谱-质谱法(SHS/GC-MS)同时测定化妆品中22种有毒挥发性有机溶剂(VOC)(二氯甲烷、顺式-1,2-二氯乙烯、反式-1,2-二氯乙烯、2-氯-1,3-丁二烯、三氯甲烷、1,2-二氯乙烷、苯、四氯化碳、三氯乙烯、甲苯、四氯乙烯、氯苯、乙苯、三溴甲烷、间二甲苯、对二甲苯、苯乙烯、邻二甲苯、异丙苯、1,4-二氯苯、1,2-二氯苯、六氯丁二烯)残留的检测方法。试样在80℃下30 min静态顶空,经DB-1柱分离后,采用选择离子监测模式(SIM)进行定性定量分析。优化了顶空、色谱和质谱参数,结果表明:22种VOC在0.5~50 ng/m L浓度范围内均呈良好的线性关系,相关系数均大于0.99,在1.0,2.0,5.0 ng/m L 3个浓度加标水平下的平均回收率为80.3%~102.7%,相对标准偏差(RSD,n=6)为6.4%~9.9%,检出限为0.2~5.0 ng/g。结果表明,该方法简便、灵敏、准确,具有良好的重现性和稳定性,适合于化妆品中22种VOC残留的筛查和确证检测。     

Determination of Cyanide in Blood for Forensic Toxicology Purposes—A Novel Nci Gc-Ms/Ms Technique

One of the recently evolving methods for cyanide determination in body fluids is GC-MS, following extractive alkylation with pentafluorobenzyl bromide or pentafluorobenzyl p-toluenesulfonate. The aim of this study was to improve previous GC methods by utilizing a triple quadrupole mass spectrometer, which could enhance selectivity and sensitivity allowing for the reliable confirmation of cyanide exposure in toxicological studies. Another purpose of this study was to facilitate a case investigation including a determination of cyanide in blood and to use the obtained data to confirm the ingestion of a substance, found together with a human corpse at the forensic scene. The blood samples were prepared following extractive alkylation with a phase transfer catalyst tetrabutylammonium sulfate and the PFB-Br derivatization agent. Optimal parameters for detection, including ionization type and multiple reaction monitoring (MRM) transitions had been investigated and then selected. The validation parameters for the above method were as follows—linear regression R² = 0.9997 in the range of 0.1 µg/mL to 10 µg/mL; LOD = 24 ng/mL; LOQ = 80 ng/mL and an average recovery of extraction of 98%. Our study demonstrates the first attempt of cyanide determination in blood with gas chromatography-tandem mass spectrometry. The established method could be applied in forensic studies due to MS/MS confirmation of organic cyanide derivative and low matrix interferences owning to utilizing negative chemical ionization.     

N_2-DART-Orbitrap中的特征气相离子反应及在西药快速检测中的应用

采用实时直接分析(DART)离子源串联高分辨质谱Orbitrap技术(DART-Orbitrap MS),对8种市售常见西药进行有效成分分析,建立了一种快速、简便、准确测定西药中有效成分的方法.对DART离子源的离子化温度、扫描模式、操作气体种类、辅助溶剂种类及其酸碱性等实验条件进行了优化,得到最佳实验条件.实验结果表明,正谱条件下,采用N_2气作为操作气体时,待测组分准分子离子峰[M+H]+同样具有较高的灵敏度和谱图辨识度.因此,N2气可以替代昂贵的He气作为DART离子源的操作气体用于8种药物有效成分的现场实时检测.该方法具备成本低、快速和操作简便的特点.通过分析待测组分的特征碎片离子,发现了N2-DART离子源中的特征离子反应,包括氧化反应和重排反应.根据获得的特征碎片离子对N_2-DART-MS中发生的反应机理进行推导,并结合理论计算对其进行验证.N_2-DART-MS技术有望应用于复杂基质混合物的现场快速检测中.     

New Ceramics Precursors Containing Si and Ge Atoms—Cubic Germasilsesquioxanes—Synthesis,Thermal Decomposition and Spectroscopic Analysis

Compounds of the silsesquioxane type are attractive material precursors. High molecular weights and well-defined structures predestine them to create ceramics with a controlled composition at the molecular level. New molecular precursors of ceramic materials with the ratio of Si:Ge = 7:1 atoms were obtained. The influence of organic substituents on the thermal decomposition processes of germasilsesquioxanes was investigated. Some of the structures obtained are characterized by a high non-volatile residue after the thermal decomposition process. The introduction of the germanium atom to the structure of the silsesquioxane molecular cage reduces the thermal stability of the obtained structures.     

气相色谱-质谱技术分析姜油树脂中的挥发性及非挥发性成分

用超临界CO2萃取生姜根茎中的姜油树脂,并用气相色谱-质谱联用技术对其进行了成分分析。从姜油树脂中分析出77种化合物,其中挥发油成分50种,主要是α-姜烯(22.29%)、 β-倍半水芹烯(8.58%)、α-法尼烯(3.93%)、 β-没药烯(3.87%)和α-姜黄烯(2.63%)等倍半萜类化合物;姜辣素成分27种,主要成分为6-姜酚(9.38%)、6-姜烯酚(7.59%)和分析过程中由姜酚类或姜烯酚类化合物受热分解而形成的姜油酮(9.24%)。在姜辣素成分中,6-异姜酚、(Z)-10-异姜烯酚和(E)-10-异姜烯酚3种化合物是新发现的未见报道的化合物。实验中对这3种新化合物进行了质谱裂解分析。     

Membrane Introduction Mass Spectrometry (MIMS): A Versatile Tool for Direct,Real‐Time Chemical Measurements

Membrane introduction mass spectrometry (MIMS) is a direct, continuous, on‐line measurement technique. It utilizes a membrane to semi‐selectively transfer analyte mixtures from a sample to a mass spectrometer, rejecting the bulk of the sample matrix, which can be a gas, liquid or solid/slurry. Analyte selectivity and sensitivity are affected by optimizations at the membrane, ionization and the mass spectrometer levels. MIMS can be roughly classified by the acceptor phase that entrains analyte(s) to the mass spectrometer after membrane transport, either a gaseous acceptor phase (GP‐MIMS) or condensed acceptor phase (CP‐MIMS). The aim of this article is to provide an introduction to MIMS as a technique and to explore current variants, recent developments and modern applications, emphasizing examples from our group, the Applied Environmental Research Laboratories as well as selected work from others in this emerging area. Also provided is a synopsis of current and future directions for this versatile analytical technique. Copyright © 2014 John Wiley & Sons, Ltd.     

Automation and Standardization—A Coupled Approach towards Reproducible Sample Preparation Protocols for Nanomaterial Analysis

Whereas the characterization of nanomaterials using different analytical techniques is often highly automated and standardized, the sample preparation that precedes it causes a bottleneck in nanomaterial analysis as it is performed manually. Usually, this pretreatment depends on the skills and experience of the analysts. Furthermore, adequate reporting of the sample preparation is often missing. In this overview, some solutions for techniques widely used in nano-analytics to overcome this problem are discussed. Two examples of sample preparation optimization by automation are presented, which demonstrate that this approach is leading to increased analytical confidence. Our first example is motivated by the need to exclude human bias and focuses on the development of automation in sample introduction. To this end, a robotic system has been developed, which can prepare stable and homogeneous nanomaterial suspensions amenable to a variety of well-established analytical methods, such as dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), field-flow fractionation (FFF) or single-particle inductively coupled mass spectrometry (sp-ICP-MS). Our second example addresses biological samples, such as cells exposed to nanomaterials, which are still challenging for reliable analysis. An air–liquid interface has been developed for the exposure of biological samples to nanomaterial-containing aerosols. The system exposes transmission electron microscopy (TEM) grids under reproducible conditions, whilst also allowing characterization of aerosol composition with mass spectrometry. Such an approach enables correlative measurements combining biological with physicochemical analysis. These case studies demonstrate that standardization and automation of sample preparation setups, combined with appropriate measurement processes and data reduction are crucial steps towards more reliable and reproducible data.     

热脱附-气相色谱-三重四极杆串联质谱法测定环境空气中的挥发性有机物

采用热脱附(TD)结合气相色谱-三重四极杆串联质谱(GC-MS/MS)建立了环境空气中23种挥发性有机物(VOCs)同时检测的分析方法。空气样品通过主动采样的方式富集到装有Tenax-TA填料的热脱附管中,热解吸后在选择反应监测(SRM)模式下用GC-MS/MS进行检测,内标法定量。结果表明,23种VOCs在0.01~1 ng和1~100 ng低、高两个范围内线性关系良好,相关系数(r²)均大于0.99,方法定量限为0.00008~1 μ g/m³。加标水平为2、10和50 ng时,23种VOCs的平均回收率为77%~124%。除了最低加标水平的氯苯,相对标准偏差(RSD, n=6)均小于20%。对市内3个采样点的环境空气进行测定,其中苯、甲苯、乙苯、二甲苯、苯乙烯、1,2,4-三甲基苯和六氯丁二烯均有检出。实验证明,该TD和GC-MS/MS相结合的检测方法具有准确、可靠、灵敏度高等优点,适用于环境空气中VOCs的同时测定。     

GC-MS与交互移动窗口因子分析法(AMWFA)用于3种陈皮挥发油成分的比较分析

将GC-MS法与新近提出的用于二维数据比较和解析的交互移动窗口因子分析法(AMWFA)结合, 对3种不同原植物来源的陈皮挥发油成分的共性和差异性进行分析, 并对重叠峰进行解析, 总共分辨出138个峰, 定性出78个峰, 其中共有组分44个.     

环境中多溴联苯醚(PBDEs)预处理技术研究进展

多溴联苯醚(PBDEs)是一类具有生态风险的新型环境有机污染物。PBDEs作为阻燃剂已愈来愈广泛地被添加到工业产品中,并对大气、水体、沉积物、土壤等环境介质产生污染,最终危害生物和人类健康。本文概述了环境样品中PBDEs分析方法研究进展,对样品前处理技术作了评述和比较,并从不同离子源和质谱类型的角度分析比较了气相色谱-质谱联用在PBDEs检测中的应用。