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1.
J Am Soc Mass Spectrom ; 35(4): 714-727, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38433439

RESUMO

The microsynthesis of 32 dialkyl derivatives of ethylphosphonic acid and the same number of monoalkyl derivatives was carried out to perform comparative studies using gas chromatography combined with mass spectrometry in chemical ionization mode which is one of the analytical techniques recommended by the Organisation for the Prohibition of Chemical Weapons (OPCW). The huge number of possible representatives makes it difficult to have complete spectral libraries of all substances in this class. Therefore, we decided to synthesize and instrumentally analyze only representatives of the selected series of homologues in this work. The analysis of the obtained results allowed us to find the rules for predicting mass spectra and the factors determining the retention parameters. Symmetrical diesters and monoesters of ethylphosphonic acid were selected for this study. During the conducted experiments using chemical ionization with methane as the reaction gas, protonated analyte molecules with high relative intensities were obtained; in many cases, these are base peaks in the spectrum. The obtained results allow grouping of the synthesized compounds depending on the introduced alkyl substituent. Retention data of the tested analytes were collected during the research by using electron ionization. The retention parameters of the tested compounds from each homologous series were also summarized and compared. Chemical Warfare Agents (CWA) analysis continues to be an important issue, especially in the context of the regular Proficiency Tests organized by the OPCW for identifying chemical compounds that are of interest to the Chemical Weapons Convention. Five compounds were synthesized whose spectra were not available in EI mass spectral libraries, and their retention indices were unknown. The identification of these substances was supported by the CI mass spectra and retention data, using previously developed relationships. Therefore, it is reasonable to conclude that the research method used is useful and effective.

2.
Sci Rep ; 14(1): 4802, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38413693

RESUMO

With growing public concern about water quality particular focus should be placed on organic micropollutants, which are harmful to the environment and people. Hence, the objective of this research is to enhance the security and resilience of water resources by developing an efficient system for reclaiming industrial/military wastewater and protecting recipients from the toxic and cancerogenic explosive compound-2,4,6-trinitrotoluene (TNT), which has been widely distributed in the environment. This research used an anodic oxidation (AO) process on a boron-doped diamond (BDD) electrode for the TNT removal from artificial and real-life matrices: marine water and treated wastewater. During experiments, TNT concentrations were significantly decreased, reaching the anodic degradation efficiency of above 92% within two hours and > 99.9% after six hours of environmental sample treatment. The presented results show the great potential of AO performed on BDD anodes for full-scale application in the industry and military sectors for TNT removal.

3.
Ecotoxicol Environ Saf ; 262: 115116, 2023 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-37315364

RESUMO

During the 20th century, thousands of tons of munitions containing organoarsenic chemical warfare agents (CWAs) were dumped into oceans, seas and inland waters around the world. As a result, organoarsenic CWAs continue to leak from corroding munitions into sediments and their environmental concentrations are expected to peak over the next few decades. There remains, however, a lack of knowledge about their potential toxicity to aquatic vertebrates, such as fish. The aim of this study was to fill in this gap in research, by investigating the acute toxicity of organoarsenic CWAs on fish embryos, using the model species, Danio rerio. To estimate the acute toxicity thresholds of organoarsenic CWAs (Clark I, Adamsite, PDCA), a CWA-related compound (TPA), as well as four organoarsenic CWA degradation products (Clark I[ox], Adamsite[ox], PDCA[ox], TPA[ox]), standardized tests were performed following the OECD no. 236 Fish Embryo Acute Toxicity Test guidelines. Additionally, the detoxification response in D. rerio embryos was investigated by analysing the mRNA expression of five genes encoding antioxidant enzymes (CAT, SOD, GPx, GR and GST). During the 96 h of exposure, organoarsenic CWAs induced lethal effects in D. rerio embryos at very low concentrations (classified as 1st category pollutants according to GHS categorization), and were therefore deemed to be serious environmental hazards. Although TPA and the four CWA degradation products caused no acute toxicity even at their maximum solubility, the transcription of antioxidant-related genes was altered upon exposure to these compounds, indicating the need for further testing for chronic toxicity. Incorporating the results of this study into ecological risk assessments will provide a more accurate prediction of the environmental hazards posed by CWA-related organoarsenicals.

4.
Sensors (Basel) ; 23(4)2023 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-36850368

RESUMO

In the five years between 2017 and 2022, IP video traffic tripled, according to Cisco. User-Generated Content (UGC) is mainly responsible for user-generated IP video traffic. The development of widely accessible knowledge and affordable equipment makes it possible to produce UGCs of quality that is practically indistinguishable from professional content, although at the beginning of UGC creation, this content was frequently characterized by amateur acquisition conditions and unprofessional processing. In this research, we focus only on UGC content, whose quality is obviously different from that of professional content. For the purpose of this paper, we refer to "in the wild" as a closely related idea to the general idea of UGC, which is its particular case. Studies on UGC recognition are scarce. According to research in the literature, there are currently no real operational algorithms that distinguish UGC content from other content. In this study, we demonstrate that the XGBoost machine learning algorithm (Extreme Gradient Boosting) can be used to develop a novel objective "in the wild" video content recognition model. The final model is trained and tested using video sequence databases with professional content and "in the wild" content. We have achieved a 0.916 accuracy value for our model. Due to the comparatively high accuracy of the model operation, a free version of its implementation is made accessible to the research community. It is provided via an easy-to-use Python package installable with Pip Installs Packages (pip).

5.
Anal Chim Acta ; 1202: 339649, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35341520

RESUMO

Nanostructured polyaniline (PANI) was electrochemically obtained as a fiber coating of solid-phase microextraction (SPME) and then used in the analysis of selected organoarsenic and organophosphorus compounds in soil samples. Also, comparative studies of the obtained PANI fibers with seven commercially available fibers for varying miscellaneous polarity, and various absorption and/or adsorption natures, were carried out. Quantitative analysis of environmental samples was performed using a gas chromatograph coupled with a tandem mass spectrometer. During the analysis of organophosphorus compounds, the PANI fiber showed at least 20% greater sorption efficiency than any commercially available fiber, whereas, in the case of organoarsenic compounds, the sorption efficiency of the PANI fiber increased with the expansion in the number of phenyl rings in the molecule. The PANI coating material was characterised by N2 adsorption-desorption, scanning electron microscopy, infrared spectroscopy and thermogravimetric analysis. SEM imaging confirmed a nanostructured form of PANI. The repeatability for one fiber (n = 7), expressed as the relative standard deviation ranges from 3.2% to 4.4% depending on the kind of tested chemical compound. The reproducibility (calculated as relative standard deviation of the 9 prepared fibers) was not greater than 7.2% Under the optimized conditions, the proposed method was linear over approximately 4 orders for organophosphorus compounds (0.02-100 ng g-1) and 5 orders for organoarsenic compounds (0.12-5000 ng g-1) of magnitude for the tested compounds, with linear determination coefficients (R2) greater than 0.972, and the limit of detection for the home-made PANI fiber was relatively low (0.006-0.45 ng g-1). In comparison with all commercially available SPME fibers, the new PANI fiber was more selective for the tested aromatic and organophosphorus compounds and easily as well as inexpensively prepared. The resulting stationary phase allowed for quantitative analysis of selected organophosphorus and organoarsenic compounds from the group of warfare agents.


Assuntos
Substâncias para a Guerra Química , Poluentes Químicos da Água , Compostos de Anilina , Substâncias para a Guerra Química/análise , Reprodutibilidade dos Testes , Microextração em Fase Sólida/métodos , Poluentes Químicos da Água/análise
6.
Materials (Basel) ; 14(20)2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34683678

RESUMO

This article presents the results of investigations of the morphology and structure of carbon deposit formed as a result of ethanol decomposition at 500 °C, 600 °C, and 700 °C without water vapour and with water vapour (0.35 and 1.1% by volume). scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM) observations as well as energy dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD), and Raman spectroscopic analyses allowed for a comprehensive characterization of the morphology and structure of cylindrical carbon nanostructures present on the surface of the Ni3Al catalyst. Depending on the reaction mixture composition (i.e., water vapour content) and decomposition temperature, various carbon nanotubes/carbon nanofibres (CNTs/CNFs) were observed: multiwalled carbon nanotubes, herringbone-type multiwall carbon nanotubes, cylindrical carbon nanofibers, platelet carbon nanofibers, and helical carbon nanotubes/nanofibres. The discussed carbon nanostructures exhibited nickel nanoparticles at the ends and in the middle part of the carbon nanostructures as catalytically active centres for efficient ethanol decomposition.

7.
J Am Soc Mass Spectrom ; 32(10): 2552-2566, 2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34478285

RESUMO

Safflower (Carthamus tinctorius L.) petals, depending on the nature of a dyeing bath, dye fibers yellow or red. This is due to the presence of two kinds of components, water-soluble yellow colorants and alkali-soluble red compounds. In this study, safflower-yellow- and safflower-red-dyed silk, cotton, and wool fibers were investigated using high- or ultrahigh-performance liquid chromatography hyphenated with spectrophotometry and tandem mass spectrometry (HPLC-UV-vis-ESI-MS/MS) and high-resolution Orbitrap mass spectrometry (HPLC-HESI-HRMS) in order to identify the natural dye in historical textiles. This way, several quinochalcone C-glycosides were separated and characterized. Their low- and high-resolution MS/MS spectra expanded the database of natural colorants in cultural heritage objects. Moreover, the colorless ct-markers (with a hitherto unknown structure) present in all safflower-dyed fabrics, regardless of the color or preservation conditions, were revealed to be E/Z stereoisomers of N1,N5,N10-tri-p-coumaroylspermidine. Since most of the standards was not available, discussion on possible molecular structures was provided. As a consequence, the analytical investigation of the reference fibers dyed with safflower demonstrated that the dye composition varies, depending on the dyeing conditions and type of fiber. Moreover, it was proven that carthamin, although alkali soluble, can be successfully released with a mild extraction method, without its hydrolysis under these conditions. The results helped us to characterize threads sampled from 16th to 18thcentury textiles of European and Near Eastern origin. It has completed the picture of natural dyes used in the most valuable textiles availed in liturgical vestments from the collections of Krakow churches.

8.
Aquat Toxicol ; 230: 105693, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33310671

RESUMO

Sea dumping of chemical warfare (CW) took place worldwide during the 20th century. Submerged CW included metal bombs and casings that have been exposed for 50-100 years of corrosion and are now known to be leaking. Therefore, the arsenic-based chemical warfare agents (CWAs), pose a potential threat to the marine ecosystems. The aim of this research was to support a need for real-data measurements for accurate risk assessments and categorization of threats originating from submerged CWAs. This has been achieved by providing a broad insight into arsenic-based CWAs acute toxicity in aquatic ecosystems. Standard tests were performed to provide a solid foundation for acute aquatic toxicity threshold estimations of CWA: Lewisite, Adamsite, Clark I, phenyldichloroarsine (PDCA), CWA-related compounds: TPA, arsenic trichloride and four arsenic-based CWA degradation products. Despite their low solubility, during the 48 h exposure, all CWA caused highly negative effects on Daphnia magna. PDCA was very toxic with 48 h D. magna LC50 at 0.36 µg × L-1 and Lewisite with EC50 at 3.2 µg × L-1. Concentrations at which no immobilization effects were observed were slightly above the analytical Limits of Detection (LOD) and Quantification (LOQ). More water-soluble CWA degradation products showed no effects at concentrations up to 100 mg × L-1.


Assuntos
Arsênio/toxicidade , Substâncias para a Guerra Química/toxicidade , Daphnia/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Arsênio/análise , Arsenicais/análise , Substâncias para a Guerra Química/análise , Cloretos/análise , Ecossistema , Dose Letal Mediana , Limite de Detecção , Água do Mar/química , Testes de Toxicidade Aguda , Poluentes Químicos da Água/análise
9.
Mar Environ Res ; 161: 105079, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32877876

RESUMO

The leakage of any substances at the sea bottom consequently leads to contamination. The polluted area will strongly depend on the type of pollution which can be dissolved, material and the physical state of the bottom layers. Although the systems that monitor the particles or pollution on the sea surface already exists, there is no similar tool for the bottom area. This work aims at developing the High Resolution Dispersion Model (HRDM) that calculates transport of the pollution in case of potential leakage from chemical ammunition dumped into the Baltic Sea. The model has been embedded into existing operational system that covers the whole region of the Baltic Sea. Thus, it consists of the three main elements: operational atmospheric model that makes calculations every day, coupled ice-ocean model covering the whole Baltic Sea area and HRDM. The horizontal resolution of the atmospheric part is about 10 km, the coupled system is driven on 2.3 km grid and HRDM is implemented on 50 m horizontal resolution. The clients are able to make integration since 2014. Access to the system is granted via REpresentational State Transfer (REST) API that separates user interface from the server site. It is possible to make simulations for instantaneous and continuous type of leakage. The results are served in binary form (as a netcdf file) and as a georeferenced tiff picture. The temporal resolution of the output data is 1 h. The HRDM consists of half-life of sulfur mustard and the results for both - with and without half-life calculations are included in the output files. The HRDM has been created as a part of Decision Support System and is not (and will not be) available for public.


Assuntos
Substâncias para a Guerra Química , Países Bálticos , Substâncias para a Guerra Química/análise
10.
Mar Environ Res ; 161: 105077, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32853855

RESUMO

Sulphur mustard (HD) was the most widely produced chemical warfare agent (CWA) in the history of chemical warfare (CW). Simultaneously, the loads of HD account as by far the largest fraction of the sea-dumped CW. Nowadays its presence in the marine ecosystems recognized as a serious threat for marine users and maritime industries. Although, during over a decade of research much has been done to assess the environmental threats linked with underwater chemical munitions. There are, however, essential gaps in scientific knowledge including scarce information about the aquatic toxicity thresholds of HD and its degradation products. Standardized biotests were performed according to the Organisation for Economic Co-operation and Development (OECD) Test No. 202: Daphnia sp. Acute Immobilisation Test guidelines. Obtained results provide a solid foundation for comparison and categorisation of threats of HD and its degradation products. With the D. magna LC50 aquatic acute toxicity threshold at as low as 224 ± 12 µg × L-1, 1,2,5-trithiepane is very toxic, being one of the most toxic CWA degradation products that have been investigated up to date. It exhibits stronger effects than 1,4,5-oxadithiepane and diluted HD that turn out to be toxic. In total, the toxicity of 7 compounds has been estimated. Whenever possible, toxicity thresholds were compared with previously existing data originating from different biotests and mathematical modelling.


Assuntos
Substâncias para a Guerra Química , Gás de Mostarda , Poluentes Químicos da Água , Animais , Substâncias para a Guerra Química/análise , Substâncias para a Guerra Química/toxicidade , Daphnia , Ecossistema , Dose Letal Mediana , Gás de Mostarda/análise , Gás de Mostarda/toxicidade , Testes de Toxicidade Aguda , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
11.
Environ Pollut ; 266(Pt 3): 115142, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32750525

RESUMO

Chemical warfare agents (CWA) dumped worldwide in all types of aquatic reservoirs pose a potential environmental hazard. Leakage of CWAs from eroding containers at dumping sites had been observed, and their presence in the tissues of aquatic animals was confirmed. However, the ecological effects of CWA have not yet been studied. In standardized laboratory bioassays, we tested if sublethal concentration of Clark I, an arsenic based CWA, can affect life histories (somatic growth rate, fecundity, size at maturity), population growth rate and stable isotope signatures of a keystone crustacean grazer Daphnia magna. We found that the life histories and fitness of daphnids reared in the presence of Clark I differed from those reared in Clark-free conditions. The effects were observed when Clark I concentrations were no less than 5 µg×L-1. With increasing concentrations of the tested CWA, all of the tested parameters decreased linearly. The finding indicates that even sublethal concentrations of Clark I can affect crustacean populations, which should be taken into account when assessing the environmental risks of this particular CWA. We found intraspecific diversity in susceptibility to Clark I, with some clones being significantly less vulnerable than others. We also found that in the presence of Clark I, the ratio of heavy and light isotopes of nitrogen in the bodies of daphnids was affected - daphnids exhibited δ15N enrichment with increasing concentrations of this CWA. The isotopic composition of carbon was not affected by the presence of Clark I. The nitrogen isotopic signature may be used as an indicator of stress in zooplankton exposed to the presence of toxic xenobiotics.


Assuntos
Arsênio , Substâncias para a Guerra Química , Poluentes Químicos da Água/análise , Animais , Daphnia , Isótopos de Nitrogênio/análise
12.
Mar Environ Res ; 161: 105112, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32861968

RESUMO

About 50 000 tons of chemical weapons (CW) were dumped to the Baltic Sea after the Second World War. Munitions are located in the deep areas of the Baltic Sea, and there they act as a point source of contamination to the ecosystem. Corroded munitions release chemical warfare agents (CWAs) to nearby water and sediments. In this study we investigated known dumpsites (Bornholm, Gotland and Gdansk Deep) and dispersed chemical munitions, to evaluate the extent of contamination of nearby sediments, as well as to assess the degradation process of released CWA. It was found that CWA-related phenylarsenic chemicals (Clark I, Clark II and Adamsite) and sulfur mustard are released to the sediments and undergo environmental degradation to chemicals, of which some remain toxic. The extent of pollution of released CWAs and their corresponding degradation products reaches more than 250 m from the CW objects, and seem to follow a power curve decrease of concentration from the source. Bornholm Deep is characterised with the highest concentration of CWAs in sediments, but occasional concentration peaks are also observed in the Gdansk Deep and close to dispersed munitions. Detailed investigation of spreading pattern show that the range of pollution depends on bottom currents and topography.


Assuntos
Substâncias para a Guerra Química , Poluentes Químicos da Água , Países Bálticos , Substâncias para a Guerra Química/análise , Substâncias para a Guerra Química/toxicidade , Ecossistema , Sedimentos Geológicos , Poluentes Químicos da Água/análise
13.
J Imaging ; 6(3)2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-34460604

RESUMO

We need data sets of images and subjective scores to develop robust no reference (or blind) visual quality metrics for consumer applications. These applications have many uncontrolled variables because the camera creates the original media and the impairment simultaneously. We do not fully understand how this impacts the integrity of our subjective data. We put forward two new data sets of images from consumer cameras. The first data set, CCRIQ2, uses a strict experiment design, more suitable for camera performance evaluation. The second data set, VIME1, uses a loose experiment design that resembles the behavior of consumer photographers. We gather subjective scores through a subjective experiment with 24 participants using the Absolute Category Rating method. We make these two new data sets available royalty-free on the Consumer Digital Video Library. We also present their integrity analysis (proposing one new approach) and explore the possibility of combining CCRIQ2 with its legacy counterpart. We conclude that the loose experiment design yields unreliable data, despite adhering to international recommendations. This suggests that the classical subjective study design may not be suitable for studies using consumer content. Finally, we show that Hoßfeld-Schatz-Egger α failed to detect important differences between the two data sets.

14.
Sci Total Environ ; 708: 135198, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31812376

RESUMO

After World War II, conventional and chemical ammunition containing mainly secondary and primary explosives was dumped in the sea. Explosives have medium toxicity to aquatic organisms, earthworms and indigenous soil microorganisms. Therefore, environmental monitoring is required, especially for dumped munitions. The main aspect of this work was to analyse the samples of lumps and sediments taken from the Baltic seabed. These samples were potentially explosives. The main goal of the study was to identify the type and composition of studied materials. In order to determine the chemical composition of samples of explosives, we used as follows: GC-MS/MS, LC-HRMS and NMR. Additionally, to determine the energetic properties we performed microcalorimetric-thermogravimetric analysis. Based on the obtained results, the composition of this explosive was TNT (41%), RDX (53%), aluminium powder (5%), and degradation products (below 1%). The resulting composition indicates that the analysed material can be classified in the "torpex" family, widely used during World War II. Regarding the results of the microcalorimetric analysis, we can conclude that excavated fragments of explosives are in very good condition and they still can detonate after being initiated. Therefore, there is a threat that they could be used for criminal or terrorist purposes.

15.
Mar Pollut Bull ; 135: 397-410, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30301051

RESUMO

Large amounts of ammunition containing 2,4,6-trinitrotoluene (TNT) and other substances were dumped in the Baltic Sea after WWII. Considering progressive corrosion processes, studying the transformation of TNT occurring in the environment constitutes an important aspect of a possible associated risk. This study focused on the transformations of TNT in simulated conditions of the Baltic Sea bottom sediment. Methods of analysis of TNT and selected products of its transformations were developed for that purpose. The developed methods allowed for the determination of selected compounds below 1 ng/g. Systematic monitoring of TNT transformations in the environment of the bottom sediment was performed. This allowed for the determination of the kinetics of TNT degradation and identification of degradation reaction products. Based on the obtained results, the TNT decay half-time in conditions present in the Baltic Sea was estimated to be 16.7 years for the abiotic environment and 5.6 for the biotic environment.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Sedimentos Geológicos/análise , Trinitrotolueno/análise , Poluentes Químicos da Água/análise , Oceano Atlântico , Biodegradação Ambiental , Substâncias Explosivas/análise , Substâncias Explosivas/metabolismo , Cromatografia Gasosa-Espectrometria de Massas/instrumentação , Cinética , Espectrometria de Massas em Tandem/métodos , Trinitrotolueno/metabolismo , Poluentes Químicos da Água/metabolismo
16.
Anal Chim Acta ; 933: 103-16, 2016 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-27497003

RESUMO

After World War II approximately 50,000 tons of chemical weapons were dumped in the Baltic Sea by the Soviet Union under the provisions of the Potsdam Conference on Disarmament. These dumped chemical warfare agents still possess a major threat to the marine environment and to human life. Therefore, continue monitoring of these munitions is essential. In this work, we present the application of new solid phase microextraction fibers in analysis of chemical warfare agents and their degradation products. It can be concluded that the best fiber for analysis of sulfur mustard and its degradation products is butyl acrylate (BA), whereas for analysis of organoarsenic compounds and chloroacetophenone, the best fiber is a co-polymer of methyl acrylate and methyl methacrylate (MA/MMA). In order to achieve the lowest LOD and LOQ the samples should be divided into two subsamples. One of them should be analyzed using a BA fiber, and the second one using a MA/MMA fiber. When the fast analysis is required, the microextraction should be performed by use of a butyl acrylate fiber because the extraction efficiency of organoarsenic compounds for this fiber is acceptable. Next, we have elaborated of the HS-SPME-GC-MS/MS method for analysis of CWA degradation products in environmental samples using laboratory obtained fibers The analytical method for analysis of organosulfur and organoarsenic compounds was optimized and validated. The LOD's for all target chemicals were between 0.03 and 0.65 ppb. Then, the analytical method developed by us, was used for the analysis of sediment and pore water samples from the Baltic Sea. During these studies, 80 samples were analyzed. It was found that 25 sediments and 5 pore water samples contained CWA degradation products such as 1,4-dithiane, 1,4-oxathiane or triphenylarsine, the latter being a component of arsine oil. The obtained data is evidence that the CWAs present in the Baltic Sea have leaked into the general marine environment.


Assuntos
Substâncias para a Guerra Química/análise , Poluentes Químicos da Água/análise , Cromatografia Gasosa , Microextração em Fase Sólida , Espectrometria de Massas em Tandem
17.
Anal Chim Acta ; 837: 52-63, 2014 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-25000858

RESUMO

Novel solid-phase microextraction (SPME) fibres containing methyl, ethyl, butyl acrylate and methacrylate were first prepared by a sol-gel technique and investigated for determination of selected organoarsenic compounds (lewisite, methyldichloroarsine, phenyldichloroarsine, diphenylchloroarsine and triphenylarsine) from water samples. The influence of sorption and desorption temperature and time for extraction efficiency were examined. The best new fibre coatings (methyl acrylate (MA), methyl methacrylate (MMA) and combination of methyl acrylate and methacrylate (MA/MMA)) for analysis of organoarsenic compounds were selected and compared with commercial fibres. The distribution coefficients Kfs were determined for the best novel fibres and for absorption commercial fibres. The highest Kfs value were obtained for MA/MMA and MMA fibres and were respectively 9458 and 6561 for lewisite and 6458 and 5884 for triphenylarsine. The limit of detection and quantification were determined for the three laboratory obtained fibres (MA, MMA and MA/MMA). LODs for tested fibres, at a signal-to-noise of 3, were 0.03-0.3 ng mL(-1). LOQs for selected coatings, at signal-to-noise of 10, were 0.1-0.8 ng mL(-1). The relative standard deviations (RSD) for all measurements were 4.3-6.5% (n=9) and relative errors were 2.5-5%. The laboratory obtained fibres were used for environmental analysis of pore water samples from the Baltic Sea.


Assuntos
Acrilatos/química , Arsenicais/química , Cromatografia Gasosa/instrumentação , Metacrilatos/química , Microextração em Fase Sólida/instrumentação , Substâncias para a Guerra Química/química , Cromatografia Gasosa/métodos , Reprodutibilidade dos Testes , Água do Mar , Sensibilidade e Especificidade , Microextração em Fase Sólida/métodos , Temperatura , Poluentes Químicos da Água/química
18.
Anal Chem ; 86(12): 5865-72, 2014 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-24831983

RESUMO

A method for detecting mustard gas degradation products thiodiglycol (TDG) and thiodiglycol sulfoxide (TDGO) in water and sediment samples using gas chromatography-tandem mass spectrometry (GC-MS/MS) after derivatization with 1-(trifluoroacetyl)imidazole (TFAI) was described. Selected reaction monitoring mode (SRM) of tandem mass spectrometry was developed for analysis of TDG and TDGO derivatives while analysis by gas chromatography-atomic emission detector (GC-AED) was performed using the 181 nm sulfur canal. TFAI derivatization conditions were optimized and the method validated. Two derivatization agents were compared, TFAI and N,O-bis(trimethylsilyl) trifluoroacetamide (BSTFA), where derivatization using TFAI occurred quicker and under milder conditions than using BSTFA. Water samples containing TDG and TDGO were evaporated to dryness under nitrogen, dissolved in organic solvent followed by reaction with TFAI. The limit of detection (LOD) for TDG and TDGO were 0.01 and 5 ng/mL, respectively. The limit of detection for TDG was decreased by two orders of magnitude if TFAI is used for derivatization rather than silyl derivatizing agents (e.g., BSTFA). TFAI has three major advantages in comparison to BSTFA, the first is much higher sensitvity, the second is a very clean background of chromatograms, and the last one is very mild conditions of derivatization. Moreover, by-products are not formed during derivatization of TDGO by TFAI in comparison to derivatization by silylating agents.

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