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  • Recent progressive preparations and applications of the SERS substrates based on silver
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-07-12
    Qing Tong, Weijia Wang, Yining Fan, Lin Dong

    In recent years, considerable interest has been focused on the development of novel surface-enhanced Raman spectroscopy (SERS) techniques. Previous studies have shown that the structures of the substrates are critical for taking advantage of strong Raman signal enhancement. This review summarizes the recent trends and developments of SERS substrates with various structures and their applications based on silver.

    更新日期:2018-07-14
  • Multi-column trajectory to advanced methods in comprehensive two-dimensional gas chromatography
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-06-30
    Yada Nolvachai, Chadin Kulsing, Khan M. Sharif, Yong Foo Wong, Sung-Tong Chin, Blagoj Mitrevski, Philip J. Marriott

    Comprehensive two-dimensional gas chromatography (GC×GC) and multidimensional GC (MDGC) offer high performance separation capability towards multi-component samples, and improved sample characterisation. Recent advances, particularly with new GC×GC methodologies, which apply additional columns to GC×GC, along with hyphenation with mass spectrometry, potentially have a tremendous impact on the analysis of various applications such as food, petrochemicals, fragrances, drugs and environmental samples. The present review highlights the new experimental designs in GC×GC coupled with MDGC to offer significant changes in operational performance, and applications of these technologies which have been developed since 2000.

    更新日期:2018-07-12
  • Multiplexed immunochemical techniques for the detection of pollutants in aquatic environments
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-07-04
    Ana Sanchis, J.-Pablo Salvador, M.-Pilar Marco

    The present article gives an overview of the situation of the aquatic ecosystem in respect to contamination by chemical pollutants and the different multiplexed techniques used to detect, identify and quantify water pollutants. A brief comparison between chromatographic and immunochemical methods is described at the beginning of this article, as an introduction of the increasing interest for multidetection of pollutants in these environments. The information regarding multiplexed immunochemical and biosensors technologies is presented emphasizing all aspects, from the importance of the design of immunizing haptens and the production of antibodies with different specificity potentials, to the establishment of different approaches to fulfill the multiplexation needs the actual environmental monitoring requires. For each class of platforms described a brief description of the physical principle, specific features, and basic concepts is presented providing additionally specific examples.

    更新日期:2018-07-12
  • The divide and conquer strategies for deep phosphoproteomics analysis
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-30
    Mingming Dong, Yating Yao, Yan Wang, Yan Jin, Mingliang Ye

    With the advance of mass spectrometry based proteomics techniques, thousands of phosphorylation sites can be identified from a single cell line or a single tissue sample by large scale global analysis. However, such large scale analysis is time consuming. And, due to the high complexity of the phosphoproteome sample, this approach is often unable to identify low abundance regulatory phosphorylation sites. Alternatively, the “divide and conquer” strategy by targeted analysis of a subset of phosphoproteome, i.e. subphosphoproteome, can improve the detection sensitivity of these phosphorylation sites. In this review, we summarized the analytical methods in this field. The enrichment approaches for the analysis of subphosphoproteomes generated by tyrosine kinases and basophilic kinases were introduced. The strategies for the analysis of the subphosphoproteomes composed by endogenous phosphopeptides, multiply phosphorylated peptides, etc., were also reviewed.

    更新日期:2018-07-12
  • On-field Raman spectroscopy of Patagonian prehistoric rock art: Pigments, alteration products and substrata
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-26
    Anastasia Rousaki, Emmanuel Vargas, Cristina Vázquez, Verónica Aldazábal, Cristina Bellelli, Mariana Carballido Calatayud, Adam Hajduk, Oscar Palacios, Luc Moens, Peter Vandenabeele

    An extensive in situ Raman spectroscopic campaign was performed on archaeological sites in three different provinces in Patagonia, Argentina (Neuquén, Río Negro and Chubut). 16 open air shelters located in different environments (forests, ecotones, steppes) were investigated and interpreted in terms of pigments used and the identification of substrata. Special attention was given to the alteration products and accretions that were found on the rock art paintings of the shelters and on the surface of the rock walls, as they can affect and damage this magnificent works of art. Haematite (α-Fe2O3) was the main chromophore that was found on the red paintings of the most of the shelters studied. The green earth glauconite, was identified only in one case, by using a red (785 nm) and a green laser (532 nm). Other minerals and silicates were found on the coloured areas but also on the rock support. Calcite (CaCO3) and gypsum (CaSO4 • 2H2O) crystallization was identified on the paintings, crusts and rock surfaces, in combination or alone, and are associated with weathering. In some cases the shelters were so severely degraded that no Raman signal of pigments and/or other components could be retrieved. Calcium oxalates were also detected in several figures and motifs in different shelters.

    更新日期:2018-07-12
  • Ionic liquid stationary phases for multidimensional gas chromatography
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-28
    He Nan, Jared L. Anderson

    Ionic liquids (ILs) are a class of organic salts that meet many of the requirements of GC stationary phases including high thermal stability, high viscosity, and tunable selectivity through the modification of the chemical structure. IL-based columns, when incorporated either in the first or second dimension, can offer unique selectivity compared to polydimethyl(siloxane) and poly(ethyleneglycol) derived GC stationary phases for the separation of complex samples by multidimensional gas chromatography. In addition, IL-based columns are emerging as superior choices for applications requiring high polarity as well as high thermal stability. The present contribution provides an overview on IL-based stationary phases for multidimensional gas chromatography with an emphasis on developments in the period from 2012 to early 2018. The analysis of various analytes (e.g., fatty acids, polycyclic aromatic sulfur heterocycles, and biodiesels) in complex matrices as well as the developments of new IL-based stationary phases for multidimensional gas chromatography are described.

    更新日期:2018-07-12
  • Current state of comprehensive two-dimensional gas chromatography-mass spectrometry with focus on processes of ionization
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-31
    Peter Q. Tranchida, Ivan Aloisi, Barbara Giocastro, Luigi Mondello

    The present article contains information on current trends in the field of the hyphenated technology comprehensive two-dimensional gas chromatography-mass spectrometry, namely the most powerful analytical tool today-available for the analysis of mixtures formed of volatile compounds. The information herein reported relates mainly to a four-year time period (2014–2017). Focus is devoted to various aspects of mass spectrometry, in particular to ionization methodologies. Apart from critical considerations on past and present research, a future perspective on processes of ionization is given.

    更新日期:2018-07-12
  • Comprehensive two-dimensional gas chromatography in forensic science: A critical review of recent trends
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-31
    B. Gruber, B.A. Weggler, R. Jaramillo, K.A. Murrell, P.K. Piotrowski, F.L. Dorman

    Comprehensive two-dimensional gas chromatography (GC × GC) has become accepted as one of the most powerful separation techniques in several application areas. In forensic investigations, however, it has not yet been entirely established due to limitations regarding standardized methodology, data interpretation and consistency of results. Nevertheless, GC × GC allows for target analysis, compound class analysis and chemical fingerprinting of samples and is therefore increasingly applied in forensic analytics. In this review, recent and significant advances in GC × GC for application to forensic studies including human scent, arson investigations, security-relevant substances and environmental forensics are discussed. The discussion includes a brief overview of the latest trends and evolutions with regard to the various forensic applications and data evaluation as well as limitations. This leads to the conclusion that the full potential of the comprehensive data sets can only be achieved by implementing standardized analysis and data processing methods.

    更新日期:2018-07-12
  • The impact of comprehensive two-dimensional gas chromatography on oil & gas analysis: Recent advances and applications in petroleum industry
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-18
    Breno J. Pollo, Guilherme L. Alexandrino, Fabio Augusto, Leandro W. Hantao

    Comprehensive two-dimensional gas chromatography (GC × GC) has impacted the workflow of GC-based methods used in petroleum industry. Application of GC × GC to petroleomic investigations have guided sample preparation to faster, cleaner, and more reliable formats. For instance, solvent consumption has been drastically reduced when using miniaturized devices in routine applications. Furthermore, flow-modulation has enabled cost-effective analysis and powerful separations of gases, fuels, and crude oils. Hyphenation of GC × GC to conventional and high resolution mass spectrometry has enabled the detection and identification of hundreds of compounds in a single analysis. Pixel-based methods enabled efficient handling of big data generated by GC × GC in forensic and geochemical investigations. This review has highlighted an ever-growing demand for modern and powerful analytical methods for oil & gas industry. Here, we described the most recent advances to sample preparation, GC × GC instrumentation, and multivariate data analysis in petroleum industry, including microextractions, high temperature GC × GC, and pixel-based data analysis.

    更新日期:2018-07-12
  • Current and future impact of 3D printing on the separation sciences
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-06-21
    Umme Kalsoom, Pavel N. Nesterenko, Brett Paull

    The potential of 3D printing to transform the field of separation science is becoming clear, based upon an increasing capacity to create highly customised devices, materials and structures, with complex geometries. The constantly improving print resolution and increasing variety of available print materials, including functional and composite materials, mean devices can be printed today, which would be extremely challenging to achieve using traditional manufacturing techniques. This review covers the majority of 3D printed devices to-date designed for use within the separation sciences, categorised under application within pre-separation, separation, and post-separation stages of analysis. It describes the impact 3D printing is having on the field, both current and future, recent achievements and challenges, and improvements required to reach its maximum potential as a transformative technology.

    更新日期:2018-07-12
  • Electrochemical biosensing using N-GQDs: Recent advances in analytical approach
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-06-23
    Ayub Karimzadeh, Mohammad Hasanzadeh, Nasrin Shadjou, Miguel de la Guardia

    This review is meant to provide an overview of the electrochemical biosensors based on Nitrogen doped graphene quantum dots (N-GQDs) for analytical approaches, along with significant advances over the last several years in related technologies. In addition, this review described: i) Most frequently applied principles in biosensing based on of N-GQDs ii) The aspects of fabrication in the perspective of biosensing applications iii) The potential of various electrochemical, biosensors for the determination of target analytes within sub-micromolar range and the circumvention of the most serious problem in biosensing will be discussed. iv) Some of multiplex electrochemical biosensors have been discussed with and without labels. v) We also summarize the latest developments in the applications of biosensors methods for detection of important analytes in real samples. vi) The development trends of biosensors are also introduced, including newly developed integrated biosensors based on (N-GQDs).

    更新日期:2018-07-12
  • 更新日期:2018-07-12
  • Wastewater-based epidemiology biomarkers: Past, present and future
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-06-23
    Phil M. Choi, Ben J. Tscharke, Erica Donner, Jake W. O'Brien, Sharon C. Grant, Sarit L. Kaserzon, Rachel Mackie, Elissa O'Malley, Nicholas D. Crosbie, Kevin V. Thomas, Jochen F. Mueller
    更新日期:2018-07-12
  • DNA-templated copper nanoparticles: Versatile platform for label-free bioassays
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-06-12
    Rui Liu, Chaoqun Wang, Jianyu Hu, Yingying Su, Yi Lv

    Label strategies are the mainstream techniques and gain great success for the sensitive quantification of biomolecules. However, they sometimes suffer from the inconveniences of time-consuming labeling, low stability of bioconjugates, and the function disorder of labeled-biomolecules. Recently, DNA-templated Cu nanoparticles (NPs) exhibit great potential for label-free fluorescent bioassays, thanks to the advantages of outstanding fluorescent properties, low toxicity, low price, good biocompatibility, and more importantly, instantaneous reaction, and facile integration with nucleic acid-based signal amplification and target-recognition strategies. In this review, we aim to discuss major developments and applications of DNA-CuNPs-based label-free assays for biomolecules. The DNA structures were manipulated for amplified sensing, multimode sensing, and versatile applications including cancer cell analysis, polyacrylamide gel electrophoresis, logic circuit, genotyping etc. Emerging analytical strategies were also discussed in detail. We address the advantages, applicable situations, and limitations of DNA-CuNPs-based label-free strategies and propose suggestions for future developments.

    更新日期:2018-07-12
  • MXene: An emerging material for sensing and biosensing
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-06-07
    Ankita Sinha, Dhanjai, Huimin Zhao, Yujin Huang, Xianbo Lu, Jiping Chen, Rajeev Jain
    更新日期:2018-07-12
  • Differential mobility spectrometers with tuneable separation voltage – Theoretical models and experimental findings
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-06-01
    Osmo Anttalainen, Jarosław Puton, Kaleva Peräkorpi, Edyta Budzyńska, Gary Eiceman, Mika Sillanpää

    Differential mobility spectrometry (DMS) is a method for identification of ions based on the nonlinear dependence of ion velocity on electric field intensity. The most important parameters characterising sensitivity and selectivity of DMS detectors are signal intensity, position of the peak in the DMS spectrum and the width of the peak. These parameters depend on the detector construction and on its control method. The shape and amplitude of the supplying (separation) voltage waveform are also very important. In this work, four different models of a DMS detector are studied. The models are based on simple algebra, partial differential equations, finite elements method and a statistical approach. All considered models give an opportunity for determining the key DMS parameters. Theoretical data are compared with the results of measurements performed with a detector of a simple structure for which tuning the parameters of separation voltage is possible.

    更新日期:2018-07-12
  • Manifold methods for telomerase activity detection based on various unique probes
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-06-07
    Chunlei Wang, Haitang Yang, Shuangshuang Wu, Yuanjian Liu, Wei Wei, Yuanjian Zhang, Min Wei, Songqin Liu

    Telomerase is a basic nuclear protein reverse transcriptase and responsible for the elongation of telomeres in cells. It has attracted a lot of attentions and acted as an important sally port for cancer diagnosis and clinical therapy. Hence, accurate and efficient determination of telomerase activity is significant. In recent years, numerous sensitive and accurate techniques have been developed for in vitro or in situ detection of telomerase activity. These methods were mainly dependent on three unique properties of elongated telomerase primer (TS primer): 1) Plenty of negative charges play important role to change interactions between biomolecules and signal probes; 2) G-rich sequences have excellent peroxidase-like catalytic activity; 3) They can be used for DNA hybridization or strand displacement reaction, which are beneficial to construct biosensors. In this review, we conclude and enumerate these advanced methods for telomerase activity detection in recent years. Development trends of telomerase detection are also prospected.

    更新日期:2018-07-12
  • Recent advances in the construction and analytical applications of metal-organic frameworks-based nanozymes
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-06-08
    Siqi Li, Xidong Liu, Hongxiang Chai, Yuming Huang

    The nanozymes are a kind of synthetic nanomaterials with enzyme-like properties. Metal–organic frameworks (MOFs) are an important class of inorganic–organic hybrid crystals. Their unique composition, structural diversity and size tailorability enable them to be promising for the construction of novel nanozymes. This review intends to summarize the recent advance for the construction of MOFs-based nanozymes and their primary applications in chemical sensing and biosensing. Based on their synthetical strategies, the MOFs-based nanozymes are categorized into four classes: pristine MOFs, MOFs with chemical modification, MOFs-based composites and MOF derivatives. In each categorization, the design and enzyme mimetic activity are discussed. Moreover, the analytical applications of these nanozymes are covered, such as the detection of H2O2, small biomolecules releasing H2O2, reductive small biomolecules, biomacromolecules, heavy metal ions, toxic metabolite of fungi, antibiotics, and so on. Finally, a summary and future perspective on the applications of MOFs-based nanozymes are briefly discussed.

    更新日期:2018-07-12
  • Opportunities and challenges of isotopic analysis by laser ablation ICP-MS in biological studies
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-06-06
    Lara Lobo, Rosario Pereiro, Beatriz Fernández

    Measurement of natural isotopic abundances and isotope ratio variations in hard tissues (such as bone, tooth, coral skeletons and otoliths) either from radiogenic and/or stable isotopes can provide important information about human evolution, palaeoenvironmental reconstructions and provenance. Besides, the addition of stable isotopically-enriched isotopes to vegetables, animals, or even humans, allows the design of a wide variety of studies to track, understand or improve biological systems. Within this context, laser ablation (LA) coupled to inductively coupled plasma - mass spectrometry (ICP-MS) is being increasingly employed for direct isotopic analysis of solids, offering the possibility to perform analyses with high spatial resolution. In this review current research and instrumental developments devoted to isotope ratio analysis by LA-ICP-MS in hard and soft biological tissues are described together with some representative applications. An outlook of challenges and research opportunities within the field is also given.

    更新日期:2018-07-12
  • Molecular modeling and prediction accuracy in Quantitative Structure-Retention Relationship calculations for chromatography
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-06-02
    Ruth I.J. Amos, Paul R. Haddad, Roman Szucs, John W. Dolan, Christopher A. Pohl

    Quantitative Structure-Retention Relationship (QSRR) methodology is a useful tool in chromatography of all kinds, allowing the prediction of analyte retention time and providing insight into the mechanisms of separation. The prediction of retention is useful in reducing method development time and identifying analytes in Non-Targeted Analysis. The varying methods used for geometry optimization, descriptor calculation, feature selection, and model generation in many different QSRR settings are investigated and compared. It is found that the method of geometry optimization and descriptor selection is of less importance than the chromatographic similarity of compounds in the training sets used for model building in order to reduce the error of the model.

    更新日期:2018-07-12
  • Towards fully integrated liquid chromatography on a chip: Evolution and evaluation
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-23
    Farideh Haghighi, Zahra Talebpour, Amir Sanati Nezhad

    Miniaturization of liquid chromatography (LC) is at the leading edge of the research topics and offers a wide range of applications in chemistry, biology, pharmaceutical, clinical diagnosis, and food analysis. The state-of-the-art “lab-on-chip” or “micro-total analysis systems” gathered scientists all over the world to provide systems with the aim of portability, reliability, reduced analysis time and cost of operation and analysis. From the hardware equipment point of view, the LC system is made by the primary compartments of solvent reservoir, pump, injector, column, and detector. In this work, we surveyed the development of LC systems and advances in each of the integrated components (i.e. pumping systems, injectors, separation channels, and detector) and the materials used for their fabrication from the beginning up to now. Finally, we summarize the application of fully integrated LC systems and exemplify about the multidimensional LCs on a chip development.

    更新日期:2018-07-12
  • Metal-organic framework (MOF)-based advanced sensing platforms for the detection of hydrogen sulfide
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-30
    Kumar Vikrant, Vanish Kumar, Yong Sik Ok, Ki-Hyun Kim, Akash Deep

    Hydrogen sulfide (H2S) is and a colorless, corrosive, flammable, and toxic gas with a characteristic rotten egg smell. Although its detection can be conducted by conventional methods (like gas chromatography), highly effective and sensitive detection of H2S has been realized with the usage of various nanomaterials (e.g., carbon nanostructures, metal nanoparticles, metal oxide nanoparticles, and quantum dots). Metal-organic frameworks (MOFs), as employed for such applications either in their pristine or modified forms, have been recognized as the effective media for sensing of H2S due to synergistic effects in addition to their well-known merits (e.g., the large specific surface). This review has been organized to describe the potential applicability of MOF-based sensing against H2S through comparative evaluation of their capability against other materials or tools. We also discuss the present obstacles and outline the future scope of research on MOF-based sensing tools.

    更新日期:2018-07-12
  • Monoelemental 2D materials-based field effect transistors for sensing and biosensing: Phosphorene, antimonene, arsenene, silicene, and germanene go beyond graphene
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-25
    Imrich Gablech, Jan Pekárek, Jaroslav Klempa, Vojtěch Svatoš, Ali Sajedi-Moghaddam, Pavel Neužil, Martin Pumera

    Graphene has been of immense interest for its interesting electronic properties, such as being a zero-band gap semiconductor. However, to be able to usefully employ graphene for electronics and electronic-transduction system sensors and biosensors, one needs to open this band gap. This proofs to be challenging on reproducible, scalable way. There are other 2D monoelemental materials that exhibit useful band gap and which can be used for field effect transistor- (FET-) based sensing and biosensing. Here we discuss trends in the development of FET-based sensors utilizing 2D phosphorene, arsenene, antimonene, silicene, and germanene.

    更新日期:2018-07-12
  • Recent trends in analytical approaches for detecting neurotransmitters in Alzheimer's disease
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-29
    Roopkumar Sangubotla, Jongsung Kim

    Alzheimer's disease is a progressive neurodegenerative disease that involves loss of memory, thinking, and reasoning and several behavioral characteristics. Alzheimer's disease affects an individual in a drastic manner by exhibiting its impact on the individual's daily routine. A completely accurate diagnosis can be achieved only after the death of a patient by observing the plaques and tangles in the brain. Hence, it is important that researchers develop robust diagnostic tools for detecting Alzheimer's disease. Neurotransmitters are suitable biomarkers for various neurological disorders, such as Parkinson's disease, Alzheimer's disease, and depression. In recent years, various analytical techniques for the detection of neurotransmitters have emerged. In this review article, we discuss the recent trends of such techniques and their limitations in the detection of various biomarkers involved in Alzheimer's disease. Furthermore, we investigate the recent progress in nanotechnology-based methods and future perspectives for the detection of neurotransmitters.

    更新日期:2018-07-12
  • Extraction techniques with deep eutectic solvents
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-09
    Sara C. Cunha, José O. Fernandes
    更新日期:2018-07-12
  • Nanozyme: An emerging alternative to natural enzyme for biosensing and immunoassay
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-26
    Qingqing Wang, Hui Wei, Zhiquan Zhang, Erkang Wang, Shaojun Dong

    Nanozyme, a term defined for nanomaterial with enzyme-like properties, has attracted significant research attention owing to its striking merits. Recently, a surge of nanozymes have been demonstrated to catalyze some typical enzymatic reactions mimicking oxidase, peroxidase and catalase. Especially, nanozymes with peroxidase-like activity have grown into a big family due to their broad range of applications in the field of biosensing and immunoassay. Since inorganic nanoparticles possess the advantages of high stability and easy surface modification, nanozymes have been emerging alternatives to natural enzymes to some extent. In this Review, we briefly summarize several typical nanozymes and then focus our attention on their enormous applications with respect to analytical chemistry. Representative examples would be discussed in detail from the literatures of last 10 years. Additionally, the current challenges and future directions about nanozymes are speculated at the end of this review.

    更新日期:2018-07-12
  • Chemometrics in forensic science
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-23
    Raj Kumar, Vishal Sharma

    This review represents a detailed discussion of the multivariate methods used in the examination of forensic exhibits; their advantages, disadvantages, and efficiency are compared. The last decade has seen the application of the chemometric methods combined with analytical techniques for characterization and discrimination of samples, which leads to the informative and representative examinations of the samples. Many research articles with reference to the use of chemometrics in forensic science have been published. This review has been divided into various sections which include chemometrics, its history, multivariate methods, and the application of chemometrics in various disciplines of forensic science. It is suggested that these new techniques and mathematical/statistical methods should be utilized in forensic science casework to get statistical confidence in the results.

    更新日期:2018-07-12
  • Food quality control by Surface Enhanced Raman Scattering
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-18
    Raymond Gillibert, Jiao Qi Huang, Yang Zhang, Wei Ling Fu, Marc Lamy de la Chapelle

    The Surface Enhanced Raman Scattering (SERS) is a powerful method to observe and detect a large panel of molecules. Through the highly enhanced Raman signal, it is possible to identify a very low concentration of molecules and to improve the limit of detection in sensor applications. In this paper, we propose a review on the use of SERS as sensor for the detection of food contaminants. We describe the different approaches and methods proposed in the literature for such detection as well as the main sensing characteristics provided by the use of this technique. All these results will be discussed and compared with other detection methods.

    更新日期:2018-07-12
  • Main complications connected with detection, identification and determination of trace organic constituents in complex matrix samples
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-30
    N. Szczepańska, M. Rutkowska, K. Owczarek, J. Płotka-Wasylka, J. Namieśnik

    It is well known that some problems with the determination of organic analytes at trace level can occur. This issue is connected with contamination during each stage of the analytical procedure from sampling to sample preparation up to chromatographic analysis, which often leads to false-positive or overestimated results. Another problem associated with determination of analytes occurs at trace- and ultra-trace level is a background problem which is mainly dictated by techniques, glassware and solvents. This review provides information on main complications connected with determination of trace organic constituents in complex matrix samples. Error sources in the field of determination of trace analytes are described in detail. In addition, the type of the background in each of the stapes of analytical procedure is summarized.

    更新日期:2018-07-12
  • Explosive detection by Surface Enhanced Raman Scattering
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-17
    Raymond Gillibert, Jiao Qi Huang, Yang Zhang, Wei Ling Fu, Marc Lamy de la Chapelle

    The Surface Enhanced Raman Scattering (SERS) has demonstrated its high efficiency to increase the Raman signal of chemical and biological species and to be able to observe and identify a very low quantity of molecules paving the way to the single molecule sensitivity. Its application to molecular detection is now intensively developed to set-up various kind of highly sensitive sensors. In this paper, we propose a review on the SERS technique and on its use as sensor for the detection of explosives, since it is of first importance in the framework of public safety. After a description of the SERS principle, we report on the different methods developed for such detection (substrates, detection principles…) and on the results obtained (targeted analytes, sensitivity, limit of detection…). We discuss all these results and compared them with other current analytical methods.

    更新日期:2018-07-12
  • In the pursuit of the holy grail of forensic science – Spectroscopic studies on the estimation of time since deposition of bloodstains
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-04-21
    Grzegorz Zadora, Alicja Menżyk

    Bloodstains can serve as a source of high-value information, allowing for the reconstruction of bloodshed events or identification of the sample donor. However, from the forensic perspective, the evidential potential of blood traces is not fully exploited. This is because despite significant research efforts, to date, no reliable method for estimating time elapsed since bloodstain deposition has been established. Nonetheless, over the last few years (2011–2017), some noteworthy advances have been made in the field of bloodstain dating, therefore the objective of the following paper is to provide a critical review of recently developed methods, with a particular emphasis on spectroscopy-based approaches. Finally, impediments to applying established procedures in routine forensic practice, along with perspectives to improve the future developments of bloodstain dating techniques, are also discussed.

    更新日期:2018-07-12
  • Recent trends in microextraction techniques used in determination of arsenic species
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-15
    Justyna Werner, Tomasz Grześkowiak, Agnieszka Zgoła-Grześkowiak, Ewa Stanisz

    The determination of arsenic species is of great importance for human health, but it is still a challenge for analytical chemistry. Complete characterization of arsenic compounds is necessary due to different toxicological effects demonstrated by particular arsenic species. Modern analytical procedures include mainly usage of microextraction techniques which tend to reduce solvent consumption, e.g. liquid phase microextraction (LPME), or employ solvent free methods, e.g. solid phase microextraction (SPME). SPME development focuses on synthesis of new sorbents and application of on-line sample preparation while in LPME usage of new solvents is studied. Among these solvents mainly ionic liquids were applied in LPME, mostly in different dispersive liquid-liquid microextraction procedures but also in hollow fibre liquid phase microextraction. As the ionic liquids are not always environmentally friendly other solvents were also proposed but only limited number of papers were devoted to usage of deep eutectic solvents or surfactants.

    更新日期:2018-07-12
  • Recent progress on surface chemistry of plasmonic metal nanoparticles for colorimetric assay of drugs in pharmaceutical and biological samples
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-26
    Suresh Kumar Kailasa, Janardhan Reddy Koduru, Mittal L. Desai, Tae Jung Park, Rakesh Kumar Singhal, Hirakendu Basu

    Plasmonic metal nanoparticles have been explored as a new class of chemical read-outs for assaying of a variety of chemical and biological species because of their unique physico-chemical and size dependent properties. Metal nanoparticles-based optical technologies are based on either new class of organic molecular assembly or with aggregation-induced optical changes features, which can also improve the sensitivity of drug assays in pharmaceutical analysis. This review describes the advantages of surface chemistry of plasmonic metal nanoparticles (e.g., silver, copper, gold, and platinum) for tuning of their colorimetric sensing applications in various drugs assays in pharmaceutical and biological samples. It provides insights of various plasmonic metal nanoparticles-based sensing strategies for the selective, sensitive and simultaneous colorimetric assay of drugs in pharmaceutical samples. Finally, we listed some research challenges to accelerate the development of plasmonic metal nanoparticles-based colorimetric sensors that are directly applicable for assaying drugs in pharmaceutical samples.

    更新日期:2018-07-12
  • How can analysts use multicriteria decision analysis?
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-11
    Marta Bystrzanowska, Marek Tobiszewski

    Proper decision making in multifacitated situation is very challenging task. It is especially difficult if there are many alternatives and criteria that are often contradictory. Analytical chemistry and related sciences involve many situations where decisions on complex problems are made. The support tools may be the use of MCDA (Multi-criteria Decision Analysis) algorithms. They formalize the decision process, make it transparent in all its aspects. In this review the application of MCDA methods in analytical and some related sciences is presented. The main areas of utilization are selection of proper materials and selection or optimization of processes. Their potential areas of applications are far from being fully explored. This review provides useful insights into the MCDA methods usage in analytical chemistry field that can stimulate the application of these tools in complex decision making processes.

    更新日期:2018-07-12
  • Determination of salivary cotinine as tobacco smoking biomarker
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-08
    Adlin N. Ramdzan, M. Inês G.S. Almeida, Michael J. McCullough, Marcela A. Segundo, Spas D. Kolev
    更新日期:2018-07-12
  • Recent advances in graphene-based freestanding paper-like materials for sensing applications
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-04
    Yao Yao, Jianfeng Ping

    There has an increasing demand on the fabrication of flexible, light-weight, robust, cost-effective, and eco-friendly freestanding paper-like materials in view of their promising applications in energy devices, sensors, actuators, and chemical filters. With the unique planar structure and outstanding properties, graphene has been recognized as the most promising building block for the development of freestanding paper-like materials for various specific applications. Here, we highlight recent progress of graphene-based freestanding paper-like materials for sensing applications. The fabrication methods for graphene-based freestanding paper-like materials are introduced completely. Three main characteristics of graphene-based freestanding paper-like materials, including mechanical performance, electrical conductivity, and biological property, are also present. The sensing applications of graphene-based freestanding paper-like materials such as electrochemical sensors, resistance sensors, and deformation sensors are discussed in details.

    更新日期:2018-07-12
  • From method validation to result assessment: Established facts and pending questions
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-04-30
    Serge Rudaz, Max Feinberg

    This paper aims to present a critical discussion of existing strategies to emphasize possible pitfalls and expected trends that arise from method validation to result assessment. It critically presents some aspects of the three main historical steps, namely terminology, method validation and quality of results. In addition to the formal link between method validation and measurement uncertainty that was recently demonstrated, the abundance of propositions also leads to some problems of consistency. Particular interest is given to the use of tolerance intervals as an appropriate tool to make decisions in method validation, control charts and determination of measurement uncertainty, considering various possibilities regarding adjustments of coverage percentage that can present difficulty for most analytical scientists.

    更新日期:2018-07-12
  • Frontiers in highly sensitive molecularly imprinted electrochemical sensors: Challenges and strategies
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-04-24
    Bin Yang, Cong Fu, Jianping Li, Guobao Xu

    Sensitivity is an important parameter of molecularly imprinted electrochemical sensors, and various methods have been extensively investigated to improve this parameter. This review focuses on recent reports about different methods that can enhance the sensitivity of these sensors. To a great extent, the sensitivity of the molecularly imprinted sensor is limited by the number of cavities formed in a molecularly imprinted polymer on an electrode after elution. To enhance sensitivity and fabricate sensing devices, researchers employ signal amplification by labels, amplification by functional materials doped in imprinted membranes, sensitive film amplification, and other methods. Some perspectives in this research area, current problems, and challenges are also outlined.

    更新日期:2018-07-12
  • Nanomaterials-based electrochemical detection of heavy metals in water: Current status, challenges and future direction
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-04-28
    Abdul Waheed, Muhammad Mansha, Nisar Ullah

    The existence of heavy metals in the natural waters poses serious threats to human health and the environment. Therefore, development of detection methods for monitoring of these heavy metals is crucial. The nanomaterial-based electrochemical sensors have been extensively employed for heavy metal ions detection. The fabricated electrodes offer several advantages and improved performance due to the design of electrode surface at the nanoscale that render increased catalytic activity and conductivity, active large surface area and fast electrode kinetics. Moreover, integration of electrochemical devices in automatic fluidic structures has also been used for a wide range of heavy metals monitoring. This review will provide a detailed account of recent progress in the development of nanomaterial-based electrochemical sensors for the detection of heavy metals in real water samples from 2013 onwards. The design of these sensors is based on the deployment of nanoparticles-modified electrodes, microelectrode and nanoelectrode arrays, and microfluidic electrochemical devices.

    更新日期:2018-07-12
  • Applications of ionic liquids in analytical chemistry with a particular emphasis on their use in solid-phase microextraction
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-04-23
    Jakub Nawała, Barbara Dawidziuk, Daniel Dziedzic, Diana Gordon, Stanisław Popiel

    Nowadays, analytical research is an indispensable factor in the lives of people. Attempts are made to improve quality, speed or safety of analytical procedures. Recently, research on ionic liquids has become a trend. This is due to the possibility of their application in many fields. In this paper, the properties and diversity of ionic liquid application have been described, especially application in advanced analytical techniques such as various electrochemical techniques, chromatography or in sample preparation. From the analytical point of view, the use of ionic liquids in solid phase microextraction is very interesting and important. In the article there are many links to research that led to the creation of a broad summary concerning these unusual chemicals. The relatively large amount of research work on the topic provides only a small peak of the potential of ionic liquids. This provides motivation for further action towards development on the topic.

    更新日期:2018-07-12
  • Advancement and prospects of bioinformatics analysis for studying bioactive peptides from food-derived protein: Sequence, structure, and functions
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-04-13
    Maolin Tu, Shuzhen Cheng, Weihong Lu, Ming Du

    Food-derived bioactive peptides, as potential ingredients in health-promoting functional foods targeting diet-related chronic diseases, have attracted increasing attention because of their high biological activities, low toxicity, and easy of metabolism in human body. However, conventional methods for analyzing the bioactive peptides are not only expensive but also time-consuming; these drawbacks limited detailed studies and rapid development of bioactive peptides. Emerging bioinformatics approaches may overcome these problems to enable bioactive peptide research. The aim of this review is to provide an overview of research progress in the bioinformatics methods used for identifying, characterizing, elaborating bioactive mechanisms of, and producing food-derived bioactive peptides, and also to present an effective workflow. The workflow has been integrated in silico and traditional methods to predict, validate, and modify bioactive peptides.

    更新日期:2018-07-12
  • Recent advances in microfluidic models for cancer metastasis research
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-04-19
    Hui Xu, Xinyao Liu, Weidong Le

    Cancer metastasis is the process of tumour cells invading from the primary tumour site to other tissues or organs in the body, which significantly increases the morbidity and mortality of cancer patients. Conventional approaches to probe cancer metastasis have several limitations: (1) invasion assays based on petri dishes are of low physiological relevance and lack the specific character of the microenvironment; (2) transwell-based transmigration assays are only semi-quantitative; and (3) animal experiments are time-consuming and lack of appropriate controls. To improve these shortcomings, microfluidic devices are developed to investigate the mechanisms of cancer metastasis, which can significantly enhance the physiological relevance and improve real-time quantitative analysis. In this paper, we review recent progress in microfluidic devices used for probing cancer metastasis. We highlight the unique features of the updated microfluidic devices and their broad application to cancer metastasis research.

    更新日期:2018-07-12
  • Nanomaterials for the sensing of narcotics: challenges and opportunities
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-07-10
    Vanish Kumar, Pawan Kumar, Anastasia Pournara, Kowsalya Vellingiri, Ki-Hyun Kim

    In recent years, nanomaterials have become a rapidly developing material technology due to their numerous advantages (e.g., high surface area, tunable surface structures, and advanced optical/electrical/mechanical features) and tremendous potential in biomedical, environmental, and energy applications. Here, we offer a comprehensive review on the advances, challenges, and opportunities of nanomaterial-based sensing technology for narcotics. To this end, the synthesis and applicability of nanomaterials (e.g., carbon-based nanostructures, semiconductor nanoparticles, metal nanoparticles, and polymer nanostructures) for narcotics sensing are described in detail along with their diverse principles/mechanisms (e.g., electrochemical, colorimetric,fluorescent, surface plasmon resonance (SPR), and surface enhanced Raman spectroscopy (SERS)). Recent progress in the development of nanomaterials has been evaluated based on sensing performance and operational conditions including parameters related to efficiency, sensitivity, accuracy, precision, reusability, and economic viability. We concluded this review by discussing the future research and development needed for nanomaterial-based sensors for narcotics.

    更新日期:2018-07-12
  • Fabrication of Fluorescent Biosensing Platform Based on Graphene Oxide-DNA and Their Application in Biomolecule Detection
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-07-09
    Si-Ying Wang, Chen-Feng Wang, Yun-Kai Lv, Shi-Gang Shen

    During the past few years, graphene oxide (GO) becomes increasingly significant in fluorescent biosensing due to its unique heterogeneous structure that offers it potential applications in various fields. Based on the transformation of affinities between GO and DNA, plenty of assays for bioanalysis have been developed rapidly, in which GO generally functions as a quencher. In this review, the current status and design mechanism of fluorescent biosensing platform based on graphene oxide-DNA are introduced in detail; the latest research progress of biomolecular fluorescence sensing has been summarized, classified and compared in this paper. Some unique and elegant ideas are introduced.

    更新日期:2018-07-12
  • Carbon nanomaterial-enabled pesticide biosensors: design strategy, biosensing mechanism, and practical application
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-07-07
    Fengnian Zhao, Jian Wu, Yibin Ying, Yongxin She, Jing Wang, Jianfeng Ping

    Due to overuse or abuse, pesticides can bring about severe residue problems, which will lead to potential toxicity for environment and human health. Consequently, it is of great importance to establish simple, rapid, robust, and reliable methods for monitoring pesticides. With outstanding properties like high electrical conductivity, catalytic activity, optical property, and favorable biocompatibility, carbon nanomaterials have been regarded as a promising candidate for the development of high-performance biosensors since they appeared. This review highlights the recent advances and new trends in carbon nanomaterial-enabled biosensors for the detection of pesticides, including the application of graphene, carbon nanotubes, carbon dots, and other carbon nanomaterials with two main biosensing ways, i.e. enzyme and enzyme-free biosensors. In addition, we briefly discuss the current challenges and future prospects for the development and application of carbon nanomaterial-enabled biosensors for pesticides analysis.

    更新日期:2018-07-12
  • Dealing with strong mass interferences of chlorinated paraffins and their transformation products: An analytical guide
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-07-07
    Lena Schinkel, Sandro Lehner, Norbert V. Heeb, Philippe Marchand, Ronan Cariou, Kristopher McNeill, Christian Bogdal

    Chlorinated paraffins (CPs) are high production volume chemicals. Their analysis is demanding and becomes even more challenging in presence of CP transformation products. Chlorinated olefins (COs) are expected thermal CP transformation products that are present in technical CP products and in the environment. Thus, a specific analysis of CPs and COs is important. Commonly, CPs are analysed by gas chromatography electron capture negative ionisation mass spectrometry (GC-ECNI-MS). It was shown that GC-ECNI-MS suffers from in-source formation of COs. Further, selected ion monitoring can lead to false quantification of COs as CPs. Alternative methods based on liquid chromatography and soft ionisation techniques can solve the CP/CO problem. Non-interfered CP data is inevitable for CP transformation studies and non-biased degradation kinetics. Data about CP transformation is urgently needed, but respective studies are challenging. In here, we provided an analytical guide to deal with severe mass interferences of CPs and their transformation products.

    更新日期:2018-07-12
  • Comprehensive Two-Dimensional Gas Chromatography in Environmental Analysis
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-07-07
    Alina M. Muscalu, Tadeusz Górecki

    Comprehensive two-dimensional gas chromatography (GC×GC) offers increased peak capacity and selectivity relative to conventional one dimensional separations. The analysis of persistent organic pollutants in environmental matrices is very challenging due to the large number of compounds with varying chemical and physical properties that are typically present in the sample at the same time at concentrations ranging from ultra-trace to percent levels. GC×GC is steadily gaining in popularity in environmental analysis and the number of publications citing the use of this technique has been increasing significantly in the recent years. An overview of the latest applications in the environmental field is presented in this paper, emphasizing the advances for targeted and non-targeted analysis in complex matrices. In addition, instrumentation, data interpretation approaches, as well as the quality assurance and control for routine analyzes are discussed.

    更新日期:2018-07-12
  • Comprehensive overview and recent advances in proteomics MS based methods for food allergens analysis
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-07-05
    Linda Monaci, Elisabetta De Angelis, Nicola Montemurro, Rosa Pilolli

    Food allergies are a serious health concern with increasing worldwide prevalence. Food legislation in place in several countries, requires detailed declaration of allergens in foods implying capability of methodologies to reliably trace food allergens. However, detecting and quantifying food allergens remains a challenge. Current common methods for food allergen analysis utilize antibody-based assays although some drawbacks are encountered such as matrix/processing effects and epitope masking especially when dealing with complex and processed foods. Therefore, sensitive, reliable, robust, fast, reproducible, and standardized methods are necessary for improved allergen analysis and reduce the risk of allergen contamination. In the last decade, mass spectrometry (MS) techniques have been developed and applied with success to food allergen detection. This review compares different aspects of food allergen quantification using advanced MS techniques including multiple reaction monitoring. The latter provides low limits of quantification for multiple allergens in complex food matrices, while being robust and reproducible.

    更新日期:2018-07-12
  • 3D-Printed Miniaturized Fluidic Tools in Chemistry and Biology
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-07-05
    C.K. Dixit, K. Kadimisetty, J. Rusling

    3D printing (3DP), an additive manufacturing (AM) approach allowing for rapid prototyping and decentralized fabrication on-demand, has become a common method for creating parts or whole devices. The wide scope of the AM extends from organized sectors of construction, ornament, medical, and R&D industries to individual explorers attributed to the low cost, high quality printers along with revolutionary tools and polymers. While progress is being made but big manufacturing challenges are still there. Considering the quickly shifting narrative towards miniaturized analytical systems (MAS) we focus on the development/rapid prototyping and manufacturing of MAS with 3DP, and application dependent challenges in engineering designs and choice of the polymeric materials and provide an exhaustive background to the applications of 3DP in biology and chemistry. This will allow readers to perceive the most important features of AM in creating (i) various individual and modular components, and (ii) complete integrated tools.

    更新日期:2018-07-12
  • X-ray fluorescence analysis of milk and dairy products: a review
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-07-03
    Galina V. Pashkova, Antonina N. Smagunova, Alexandr L. Finkelshtein

    A small mineral fraction substantially determines the nutrition value and quality of milk. The X-ray fluorescence spectrometry (XRF) is an expanding method in the field of elemental analysis of milk. Different configurations of XRF spectrometers are commercially available, and they are known as providing cheap and fast analyses of minerals and some trace elements with the accuracy and reproducibility required for food products. This research review particularly concerns the XRF instrumentation, sample preparation, calibration and quantification procedures. The practical examples of using XRF techniques for determination of minerals and trace elements in milk samples are also demonstrated.

    更新日期:2018-07-12
  • Liquid-phase microextraction – The different principles and configurations
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-06-30
    Yadollah Yamini, Maryam Rezazadeh, Shahram Seidi

    Liquid-phase microextraction is a miniaturized form of traditional liquid–liquid extraction in which the extracting organic phase is limited to a few microliters for extraction of target analytes. Despite the advantages of solid-phase microextraction, liquid-phase microextraction was also rapidly become a popular method due to its unique characteristics. Different liquid-phase microextraction systems have been introduced in order to simplify the extraction approach, increase the selectivity and sample cleanup, efficiency enhancement and make the extraction of various classes of analytes possible. Herein, different microextraction methods, including single drop microextraction, dispersive liquid–liquid microextraction, solidified floating organic drop and hollow fiber based liquid-phase microextraction were reviewed and their principles and configurations were compared. This review is mostly focused on the characteristics of present liquid-phase microextraction techniques and compares the efficiencies of these techniques over each other.

    更新日期:2018-07-12
  • Conformational Analysis of Complex Protein States by Hydrogen/Deuterium Exchange Mass Spectrometry (HDX-MS): Challenges and Emerging Solutions
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-06-27
    Esben Trabjerg, Zeinab E. Nazari, Kasper D. Rand

    Hydrogen/deuterium mass spectrometry (HDX-MS) has within the last 25 years evolved to become a well-established technique for analysing the solution-phase conformational dynamics and molecular interactions of proteins, attributes that can be difficult to access by other methods for structural analysis. This reviews present the latest development within HDX-MS with a special focus on how improvements in instrumentation, methodology and data analysis have expanded the capability of HDX-MS to analyse complex and hitherto elusive protein states. Such protein states include large or multi-protein complexes, lipid-associated or integral membrane proteins, proteins with highly dynamic regions, disulfide-bonded proteins, heavily glycosylated proteins and proteins in formulations.

    更新日期:2018-07-12
  • Characterization of odorant patterns by comprehensive two-dimensional gas chromatography: A challenge in omic studies
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-06-14
    Chiara Cordero, Johannes Kiefl, Stephen E. Reichenbach, Carlo Bicchi

    Sensomics, like other “omics” fields, cuts across chemistry and biology and so requires holistic strategies capable of comprehensively mapping the set of all potential ligands (e.g., sensometabolome) that trigger the multimodal perception of food flavor. These complex mixtures when directed to odor receptors in the nose, define the so-called Chemical Odor Code. Analytical chemistry is challenged to comprehensively map the complex volatile fractions of real samples, including odorants and interferents, and define univocal odor patterns for correlative studies. This review critically discusses state-of-the-art research in the field of odorants and volatiles characterization in food by comprehensive two-dimensional gas chromatography, illustrating how hyphenation with mass spectrometry and olfactometry, accurate quantitation, suitable sample preparation, and dedicated data mining can capture essential information on odor patterns exploiting the higher level of information on sample sensory features.

    更新日期:2018-07-12
  • Recent advances in modulator technology for comprehensive two dimensional gas chromatography
    Trends Anal. Chem. (IF 7.034) Pub Date : 2018-05-05
    H. Daniel Bahaghighat, Chris E. Freye, Robert E. Synovec

    One of the greatest advancements in the field of gas chromatography (GC) has been the development of comprehensive two-dimensional gas chromatography (GC × GC). As the field of GC evolved from one-dimensional gas chromatography (1D-GC) to heart cutting (GC–GC), followed by the advent of GC × GC, the critical component at the center of this evolution has been the interface between the separation columns. The interface, referred to as the modulator for GC × GC, links the primary and secondary columns. This review covers the evolution of modulator systems from the founding of GC × GC in 1991 by Liu and Phillips, while focusing on the last six years. Since its inception, modulators have evolved into two distinct categories: thermal, and valve-based. The advantages and shortcomings of each category will be covered. Recent developments in the research, development, and commercialization of these various modulators is provided, with a glimpse into future modulator designs.

    更新日期:2018-07-12
  • Trends on (elemental and molecular) mass spectrometry based strategies for speciation and metallomics
    Trends Anal. Chem. (IF 7.034) Pub Date : 2017-10-03
    M. Montes-Bayón, M. Sharar, M. Corte-Rodriguez

    The capabilities of electrospray ionization (ESI) and matrix assisted laser desorption/ionization (MALDI) to permit species identification in combination with inductively coupled plasma (ICP) mass spectrometry to conduct element-tagged species monitoring have been exploited for a number of applications in speciation studies over the years. In this review, we report the new trends in the combined application of these techniques to address the structural and quantitative insights for different speciation/metallomics issues including the monitoring of natural elemental labels and drug metabolism products as well as the characterization of metallic nanoparticles and their corresponding metal ions. In addition, the trends on the analysis of trace elements in single cells by elemental MS together with the exponential growth of the imaging experiments, are also covered.

    更新日期:2018-07-08
  • Advances in electrospray mass spectrometry for the selenium speciation: Focus on Se-rich yeast
    Trends Anal. Chem. (IF 7.034) Pub Date : 2017-10-20
    Katarzyna Bierla, Simon Godin, Ryszard Lobinski, Joanna Szpunar

    Selenium is an essential element of which the deficiency is often compensated for by supplementation with products based on yeast grown on Se-rich media. Advances in HPLC with element- and molecule-specific detection by mass spectrometry have resulted in evidence of the presence of hundreds of selenocompounds in Se-rich yeast, with different properties and in a large concentration range. This spurs interest in extending –omics-type approaches to selenium speciation analysis to other samples with the ultimate goal to confer biological significance to the obtained data. This review critically evaluates the recent advances in selenium speciation analysis, especially in terms of sensitivity and specificity of ICP-MS and electrospray-MS, and, in terms of resolution, mass accuracy and multistage fragmentation by electrospray-MS. A focus is made on the evolution of the perception of the competitiveness and complementarity of ICP-MS and electrospray-MS detection in HPLC for qualitative and quantitative Se speciation analysis.

    更新日期:2018-07-08
  • Advances in mass spectrometry for iron speciation in plants
    Trends Anal. Chem. (IF 7.034) Pub Date : 2017-11-10
    Ghaya AlChoubassi, Justyna Aszyk, Paulina Pisarek, Katarzyna Bierla, Laurent Ouerdane, Joanna Szpunar, Ryszard Lobinski

    Iron is an important nutrient essential for plants and critical for human health. The state-of-the art of methods for iron speciation in cereal grains and plant fluids is critically reviewed. Particular attention is given to the latest developments in the coupling of HPLC with the parallel ICP MS and electrospray ionization (ESI) MS/MS detection, usually QTOF MS or Q-Orbitrap MS, for the identification and quantification of iron species. The coupled techniques allow the direct microanalysis of plant intracellular fluids (xylem and phloem) and complement X-ray absorption spectroscopy (XANES and EXAFS). The increasing resolution and sensitivity of electrospray mass spectrometers and emergence of software allowing extraction of iron specific data from large chromatographic data sets are responsible for the growing role of electrospray MS/MS in speciation studies. The use of stable isotopes for the probing of the reactivity and stability of endogenous metal complexes and quantitative analysis are rising in importance.

    更新日期:2018-07-08
  • Recent trends in element speciation analysis of crude oils and heavy petroleum fractions
    Trends Anal. Chem. (IF 7.034) Pub Date : 2017-10-28
    Sara Gutiérrez Sama, Caroline Barrère-Mangote, Brice Bouyssière, Pierre Giusti, Ryszard Lobinski

    Medium and heavy crude oils and high-boiling distillation fractions which are increasingly used in petroleum industry contain high concentrations of sulfur and metals. Their behavior in refining processes is critically dependent on the speciation. Recent analytical developments, especially on the level of coupled techniques and high-resolution mass spectrometry, start allowing the speciation of individual metal compounds in crude oil known for its extreme complexity. These developments include: (i) GC stationary phases of high thermal stability and the high-temperature interfaces with ICP-MS and TOF-MS; (ii) high-efficiency microcolumn gel-permeation chromatography with detection by sector-field ICP-MS; (iii) thin layer chromatography coupling with laser ablation ICP-MS detection; and (iv) two-dimensional separation protocols increasing the purity of heteroelement containing fractions. Progress in electrospray and atmospheric-pressure photoionization Fourier Transform MS allows resolutions of above 1,000,000 to be achieved making it possible to identify by accurate mass measurement individual sulfur and metal species directly in crude oils.

    更新日期:2018-07-08
  • Critical assessment of hexavalent chromium species from different solid environmental, industrial and food matrices
    Trends Anal. Chem. (IF 7.034) Pub Date : 2017-12-29
    F. Séby, V. Vacchina

    The accurate determination of Cr(VI), the most hazardous form of chromium, is an analytical challenge because of its facility to be reduced during all steps of the analytical procedure. This review presents a synthesis of the available studies for the analysis of Cr species in different solid samples (soils/wastes, working atmosphere, industrial and food samples). A particular attention has been paid on Cr(III) and Cr(VI) interconversions that can occur during extraction and efforts made to avoid these reactions. Although the use of NaOH/Na2CO3 solutions with heating at 90–95°C is the more widespread procedure, species transformation can still occur and several studies suggest that speciated isotope dilution (SID) could be a suitable tool for correction of these interconversions.

    更新日期:2018-07-08
  • Speciation of technologically critical elements in the environment using chromatography with element and molecule specific detection
    Trends Anal. Chem. (IF 7.034) Pub Date : 2017-09-22
    Justyna Wojcieszek, Joanna Szpunar, Ryszard Lobinski

    The growing release of technology-critical elements (TCEs): Ga, Ge, In, Nb, Ta, Te, Tl, and most of the platinum group elements (PGEs), and rare earth elements (REEs) requires the understanding of their mobility, reactivity and chemical transformations in the environment which are critically dependent on their chemical form (speciation). The total concentrations of these elements at the trace levels make their speciation analysis challenging. Coupled techniques combining a high resolution chromatographic separation with ultrasensitive element-specific detection by inductively coupled plasma mass spectrometry (ICP MS) often offer the unique possibility of accessing the information on the identities and concentrations of individual metal species present in environmental samples. This paper reviews the advantages and limitations of these techniques to TCEs speciation and highlights the development trends in analytical methodology that may contribute to our understanding of the risks associated with the increasing environmental presence of TCEs.

    更新日期:2018-07-08
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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