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Analytical and Bioanalytical Chemistry

Frank Neugebauer, Annekatrin Dreyer, Nina Lohmann, Jan Koschorreck
The extensive application of halogenated flame retardants has led to their widespread distribution in the environment. Recently, concerns emerged regarding their potential persistence, (bio)accumulation, and/or toxicity. Particularly halogenated flame retardants based on norbornene structures, like Dechlorane Plus as well as other brominated PBDE replacements, generically called emerging, novel, or alternative flame retardants, are in the focus of interest. A comprehensive analytical method for the determination of 21 halogenated flame retardants (HFRs) of different substance classes (dechloranes, brominated aromates, brominated ethers, cyclic BFR) in a broad variety of matrices (tree leaves, fish fillet, birds eggs, suspended particles) was developed in order to assess their environmental levels as well as temporal trends, especially for the use within environmental specimen banks (ESBs)...
December 13, 2017: Analytical and Bioanalytical Chemistry
Uri Keshet, Paulina Goldshlag, Aviv Amirav
We explored the use of pulsed flow modulation (PFM) two-dimensional comprehensive gas chromatography (GCxGC) mass spectrometry with supersonic molecular beams (SMB) (also named Cold electron ionization (EI)) for achieving universal pesticide analysis in agricultural products. The use of GCxGC serves as an alternative to MS-MS in the needed reduction of matrix interference while enabling full-scan MS operation for universal pesticide analysis with reduced number of false negatives. Matrix interference is further reduced with Cold EI in view of the enhancement of the molecular ions...
December 13, 2017: Analytical and Bioanalytical Chemistry
Maria Montes-Bayón
No abstract text is available yet for this article.
December 12, 2017: Analytical and Bioanalytical Chemistry
Laping Liu, Zhengmeng Wang, Sihan Zhao, Jiahui Duan, Hu Tao, Wenji Wang, Shuhui Liu
A simple sample preparation method requiring minimal organic solvents is proposed for the determination of the total phthalate content in cosmetics by high-performance liquid chromatography-tandem mass spectrometry. The hydrolysis of phthalates and purification of interfering substances were performed in a three-phase system that included an upper n-hexane phase, a middle ethanol phase, and a lower aqueous alkali solution. This three-phase system utilized an incremental purification strategy. The apolar ingredients were extracted with n-hexane, the polar pigments accumulated in the ethanol phase, and the hydrolysis product, phthalic acid, remained in the hydrolysate...
December 9, 2017: Analytical and Bioanalytical Chemistry
P Abdul Rasheed, Jae-Seung Lee
We developed a highly sensitive and selective sensor based on the nanoprobe conjugates of catalytic nanoparticles and double-stranded DNA (dsDNA) for the colorimetric detection of NF-κB protein. The sensing mechanism takes advantage of the catalytic activity of nanoparticle surfaces and the specific binding of NF-κB to a dsDNA sequence. In the presence of NF-κB, the highly selective interactions between dsDNA and NF-κB lead to the passivation of the catalytic nanoparticle surfaces, impeding the sodium borohydride-mediated reduction rate of 4-nitrophenol...
December 9, 2017: Analytical and Bioanalytical Chemistry
Lee L Yu, Joseph F Browning, Carolyn Q Burdette, George C Caceres, Kaitlyn D Chieh, W Clay Davis, Brittany L Kassim, Stephen E Long, Karen E Murphy, Rabia Oflaz, Rick L Paul, Katherine E Sharpless, Laura J Wood, James H Yen, Rolf Zeisler
A Standard Reference Material (SRM) of seaweed, SRM 3232 Kelp Powder (Thallus laminariae) has been developed to support food and dietary supplement measurements in compliance with the Food Safety Modernization Act (FSMA) and the Dietary Supplement Health and Education Act of 1994 (DSHEA). The material was characterized for nutritional minerals, arsenic species, isomers of vitamin K1, proximates, and toxic elements. Kelp is a rich source of vitamins and minerals, and it is an excellent source of dietary iodine...
December 9, 2017: Analytical and Bioanalytical Chemistry
Juris Meija, Michelle M G Chartrand
Isotope delta measurements are normalized against international reference standards. Although multi-point normalization is becoming a standard practice, the existing uncertainty evaluation practices are either undocumented or are incomplete. For multi-point normalization, we present errors-in-variables regression models for explicit accounting of the measurement uncertainty of the international standards along with the uncertainty that is attributed to their assigned values. This manuscript presents framework to account for the uncertainty that arises due to a small number of replicate measurements and discusses multi-laboratory data reduction while accounting for inevitable correlations between the laboratories due to the use of identical reference materials for calibration...
December 7, 2017: Analytical and Bioanalytical Chemistry
Bartosz Setner, Zbigniew Szewczuk
Quaternary ammonium salts (QAS), both linear and bicyclic, are often utilized to improve the mass spectrometry (MS) analysis of peptides by fixing a permanent positive charge on the analyzed molecule. However, during collision-induced dissociation (CID) experiments, QAS undergo unwanted side reactions-Hofmann elimination as well as a tertiary amine loss- rendering the data interpretation complicated. In this work, we present 2-thia- and 2-oxa-5-azoniaspiro[4.4]nonyl groups as heterocyclic derivatives of the highly stable ionization group, 5-azoniaspiro[4...
December 6, 2017: Analytical and Bioanalytical Chemistry
Yuanyuan Li, Nan Zhu, Yulong Ma, Qiang Li, Peng Li
Material with a core-shell structure based on a porous silica core and Ag nanoparticles (AgNPs) as shell (SiO2@Ag) was prepared with the seed growth method. Cellulose derivatives as chiral selectors were coated on the surfaces of SiO2@Ag particles by means of coating and intermolecular polycondensation as chiral stationary phases (CSPs), respectively. Fifteen racemates were used to evaluate their chiral recognition ability by high-performance liquid chromatography (HPLC). The results implied that the CSPs based on SiO2@Ag particles obtained stronger interaction with the analytes leading to better enantioseparation due to the existence of AgNPs on the surfaces of silica gel, compared with a cellulose derivative-modified silica column...
December 6, 2017: Analytical and Bioanalytical Chemistry
Pedro José Barroso, Julia Martín, Juan Luis Santos, Irene Aparicio, Esteban Alonso
In this work, an analytical method, based on sonication-assisted extraction, clean-up by dispersive solid-phase extraction and determination by liquid chromatography-tandem mass spectrometry, has been developed and validated for the simultaneous determination of 15 emerging pollutants in leaves from four ornamental tree species. Target compounds include perfluorinated organic compounds, plasticizers, surfactants, brominated flame retardant, and preservatives. The method was optimized using Box-Behnken statistical experimental design with response surface methodology and validated in terms of recovery, accuracy, precision, and method detection and quantification limits...
December 6, 2017: Analytical and Bioanalytical Chemistry
Samaneh Akbarzade, Mahmoud Chamsaz, Gholam Hossein Rounaghi, Mahdi Ghorbani
A selective and sensitive magnetic dispersive solid-phase microextraction (MDSPME) coupled with gas chromatography-mass spectrometry was developed for extraction and determination of organophosphorus pesticides (Sevin, Fenitrothion, Malathion, Parathion, and Diazinon) in fruit juice and real water samples. Zero valent Fe-reduced graphene oxide quantum dots (rGOQDs@ Fe) as a new and effective sorbent were prepared and applied for extraction of organophosphorus pesticides using MDSPME method. In order to study the performance of this new sorbent, the ability of rGOQDs@ Fe was compared with graphene oxide and magnetic graphene oxide nanocomposite by recovery experiments of the organophosphorus pesticides...
December 6, 2017: Analytical and Bioanalytical Chemistry
Mohsen Talebi, Rahul A Patil, Leonard M Sidisky, Alain Berthod, Daniel W Armstrong
Twelve bis- or dicationic ionic liquids (ILs) including eight based on imidazolium, a single one based on phosphonium, and three based on pyrrolidinium cationic units were prepared with the bis(trifluoromethyl sulfonyl) imide anion. The two identical cationic moieties were attached by different alkyl spacers having three or five carbons and differing alkyl substituents attached to the spacer. The SLB-IL111 column, as the most polar commercial stationary phase known, was included in the study for comparison...
December 6, 2017: Analytical and Bioanalytical Chemistry
Astrid Tannert, Anuradha Ramoji, Ute Neugebauer, Jürgen Popp
Despite the strong decline in the infection-associated mortality since the development of the first antibiotics, infectious diseases are still a major cause of death in the world. With the rising number of antibiotic-resistant pathogens, the incidence of deaths caused by infections may increase strongly in the future. Survival rates in sepsis, which occurs when body response to infections becomes uncontrolled, are still very poor if an adequate therapy is not initiated immediately. Therefore, approaches to monitor the treatment efficacy are crucially needed to adapt therapeutic strategies according to the patient's response...
December 6, 2017: Analytical and Bioanalytical Chemistry
Leire Mijangos, Haizea Ziarrusta, Maitane Olivares, Olatz Zuloaga, Monika Möder, Nestor Etxebarria, Ailette Prieto
A new procedure using polyethersulfone (PES) microextraction followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis was developed in this work for the simultaneous determination of 41 multiclass priority and emerging organic pollutants including herbicides, hormones, personal care products, and pharmaceuticals, among others, in seawater, wastewater treatment plant (WWTP) effluents, and estuary samples. The optimization of the analysis included two different chromatographic columns and different variables (polarity, fragmentor voltage, collision energy, and collision cell accelerator) of the mass spectrometer...
December 6, 2017: Analytical and Bioanalytical Chemistry
Amani Y Alhalwani, John E Repine, Michelle K Knowles, J Alex Huffman
Lactoferrin (LF) is an important multifunctional protein that comprises a large fraction of the protein mass in certain human fluids and tissues, and its concentration is often used to assess health and disease. LF can be nitrated by multiple routes, leading to changes in protein structure, and nitrated proteins can negatively impact physiological health via nitrosative stress. Despite an awareness of the detrimental effects of nitrated proteins and the importance of LF within the body, cost-effective methods for detecting and quantifying nitrated lactoferrin (NLF) are lacking...
December 6, 2017: Analytical and Bioanalytical Chemistry
Javier Izquierdo, Peter Knittel, Christine Kranz
Scanning electrochemical microscopy (SECM) has evolved from an electrochemical specialist tool to a broadly used electroanalytical surface technique, which has experienced exciting developments for nanoscale electrochemical studies in recent years. Several companies now offer commercial instruments, and SECM has been used in a broad range of applications. SECM research is frequently interdisciplinary, bridging areas ranging from electrochemistry, nanotechnology, and materials science to biomedical research...
December 6, 2017: Analytical and Bioanalytical Chemistry
Richard Bade, Jason M White, Cobus Gerber
The combination of qualitative and quantitative bimonthly analysis of pharmaceuticals and illicit drugs using liquid chromatography coupled to mass spectrometry is presented. A liquid chromatography-quadrupole time of flight instrument equipped with Sequential Window Acquisition of all THeoretical fragment-ion spectra (SWATH) was used to qualitatively screen 346 compounds in influent wastewater from two wastewater treatment plants in South Australia over a 14-month period. A total of 100 compounds were confirmed and/or detected using this strategy, with 61 confirmed in all samples including antidepressants (amitriptyline, dothiepin, doxepin), antipsychotics (amisulpride, clozapine), illicit drugs (cocaine, methamphetamine, amphetamine, 3,4-methylenedioxymethamphetamine (MDMA)), and known drug adulterants (lidocaine and tetramisole)...
December 6, 2017: Analytical and Bioanalytical Chemistry
Jing Zhang, Lijia Liang, Xin Guan, Rong Deng, Huixin Qu, Dianshuai Huang, Shuping Xu, Chongyang Liang, Weiqing Xu
A surface-enhanced Raman scattering (SERS) method for in situ detection and analysis of the intranuclear biomolecular information of a cell has been developed based on a small, biocompatible, nuclear-targeting alkyne-tagged deoxyribonucleic acid (DNA) probe (5-ethynyl-2'-deoxyuridine, EDU) that can specially accumulate in the cell nucleus during DNA replications to precisely locate the nuclear region without disturbance in cell biological activities and functions. Since the specific alkyne group shows a Raman peak in the Raman-silent region of cells, it is an interior label to visualize the nuclear location synchronously in real time when measuring the SERS spectra of a cell...
December 6, 2017: Analytical and Bioanalytical Chemistry
Xiangpeng Li, Christopher J Easley
Recent breakthroughs in organ-on-a-chip and related technologies have highlighted the extraordinary potential for microfluidics to not only make lasting impacts in the understanding of biological systems but also to create new and important in vitro culture platforms. Adipose tissue (fat), in particular, is one that should be amenable to microfluidic mimics of its microenvironment. While the tissue was traditionally considered important only for energy storage, it is now understood to be an integral part of the endocrine system that secretes hormones and responds to various stimuli...
December 6, 2017: Analytical and Bioanalytical Chemistry
Tingting Xu, Anna Young, Enolia Marr, Gary Sayler, Steven Ripp, Dan Close
An autonomously bioluminescent Saccharomyces cerevisiae BLYAhS bioreporter was developed in this study for the simple and rapid detection of dioxin-like compounds (DLCs) and aryl hydrocarbon receptor (AhR) agonists. This recombinant yeast reporter was based on a synthetic bacterial luciferase reporter gene cassette (lux) that can produce the luciferase as well as the enzymes capable of self-synthesizing the requisite substrates for bioluminescent production from endogenous cellular metabolites. As a result, bioluminescent signal production is generated continuously and autonomously without cell lysis or exogenous reagent addition...
December 6, 2017: Analytical and Bioanalytical Chemistry
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