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Szczurek A.,Wroclaw University of Technology | Maziejuk M.,Military Institute of Chemistry and Radiometry | Maciejewska M.,Wroclaw University of Technology | Pietrucha T.,Wroclaw University of Technology | Sikora T.,Military Institute of Chemistry and Radiometry
Sensors and Actuators, B: Chemical | Year: 2017

Benzene, toluene, and xylene, called BTX compounds, are broadly distributed in the environment. They frequently co-occur in air, water and soil because of common emission sources. However, these compounds differ considerably in terms of impact, in particular on human health. Due to this fact, measurement techniques are needed, which allow for identification of individual BTX compounds in the environment. The aim of the work was to show that differential ion mobility spectrometry (DMS) is capable of recognizing benzene, toluene or xylene in filtered air containing various amount of water vapor. For this purpose, the compounds recognition was represented as the classification problem. The discriminative power of DMS spectra, obtained for negative and positive ions, were explored as the basis for classification. We demonstrated that benzene, toluene, or xylene may be recognized with 100% success rate, in filtered air with varying humidity (from 0 to 77% RH). The best results, achieved with a relatively simple k-nearest neighbor classifier, were based on DMS spectrum for negative ions, recorded in full range of separation and compensation voltages. We believe, that the demonstration of a successful coupling of DMS and classification technique will contribute to further development of this analytical technique as well as its application in the environmental assessment. © 2016


Bratek W.,Wroclaw University of Technology | Swiatkowski A.,Military University of Technology | Pakula M.,Naval University of Gdynia | Biniak S.,Nicolaus Copernicus University | And 2 more authors.
Journal of Analytical and Applied Pyrolysis | Year: 2013

Poly(ethylene)terephthalate (PET) waste was subjected to carbonization in a nitrogen stream at 1098 K. The coke was then activated in a carbon dioxide stream under various conditions: temperatures of 1173, 1198 and 1213 K as well as process times of 4, 5, 6 and 8 h. The activated carbons were characterized using various methods: the structure from Raman and XRD measurements, the porosity from low temperature nitrogen adsorption, the surface properties from cyclic voltammetry and the hydrogen storage capacity from the low temperature adsorption isotherm of H2. The results demonstrated the importance of the temperature and the duration of the process. Higher temperatures result in the etching of graphitic domains of better crystallinity. A relatively small increase in activation time at the highest temperature used yielded a significant increase in the degree of burn-off and porous structure development. The microporosity of these carbons is similar to that of commercial activated carbons. They also have a similar capacity to adsorb water pollutants (e.g. 4-chlorophenol). The PET carbon sample with maximum burn-off exhibited higher values of the microporous structure parameters and the electric double layer capacity in electrolyte solution than the other three samples. The same sample exhibits a sufficient hydrogen storage capacity, which after optimization of the activation conditions should yield an effective storage material. This confirms the possibility of producing activated carbon from waste PET with satisfactory properties by the simple processes of carbonization and activation. The activated carbons obtained have potential use as water pollutant adsorbents, low-cost materials for hydrogen storage and electrode materials in supercapacitors or fuel cells. © 2012 Elsevier B.V.


Maziejuk M.,Military Institute of Chemistry and Radiometry | Puton J.,Military University of Technology | Szyposzynska M.,Military Institute of Chemistry and Radiometry | Witkiewicz Z.,Military University of Technology
Talanta | Year: 2015

The subject of the work is the use of differential mobility spectrometry (DMS) for the detection of chemical warfare agents (CWA). Studies were performed for mustard gas, i.e., bis(2-chloroethyl)sulfide (HD), sarin, i.e., O-isopropyl methylphosphonofluoridate (GB) and methyl salicylate (MS) used as test compounds. Measurements were conducted with two ceramic DMS analyzers of different constructions allowing the generation of an electric field with an intensity of more than 120 Td. Detector signals were measured for positive and negative modes of operation in a temperature range from 0 to 80 °C. Fragmentations of ions containing analyte molecules were observed for all tested compounds. The effective temperatures of fragmentation estimated on the basis of dispersion plots were equal from about 148 °C for GB to 178 °C for MS. It was found that values of separation voltage (SV) and compensation voltage (CV) at which the fragmentation of sample ions is observed may be the parameters improving the certainty of detection for different analytes. The DMS analyzers enabling the observation of ion fragmentation can be successfully used for effective CWA detection. © 2015 Published by Elsevier B.V.


Dziura A.,Military University of Technology | Marszewski M.,Kent State University | Choma J.,Military University of Technology | De Souza L.K.C.,Kent State University | And 3 more authors.
Industrial and Engineering Chemistry Research | Year: 2014

A series of microporous carbons was obtained through carbonization of Saran polymer (poly(vinylidene chloride-co-vinyl chloride)) at various temperatures. The resulting carbons were also activated with KOH to obtain highly microporous carbons. The activated carbons possessed well-developed porous structures: specific surface area in the range 1460-2200 m2/g, micropore volume in the range of 0.65-0.96 cm3/g, and ultramicropore volume in the range of 0.18-0.25 cm3/g. The well-developed porous structure of these carbons resulted in high CO2 and benzene uptakes: CO2 uptake of 6.7 mmol/g at 0 °C and 3.9 mmol/g at 25 °C (both at ca. 800 mmHg) and benzene uptake of 11.6 mmol/g at 20 °C (at a pressure close to the saturation vapor pressure). This study shows that simple but controlled carbonization and activation of commercially available polymers such as Saran can afford high surface area carbon sorbents for CO2 and benzene adsorption and for related environment remediation applications. © 2014 American Chemical Society.


Choma J.,Military University of Technology | Marszewski M.,Kent State University | Osuchowski L.,Military Institute of Chemistry and Radiometry | Jagiello J.,Micromeritics Instrument Co. | And 2 more authors.
ACS Sustainable Chemistry and Engineering | Year: 2015

Two sets of activated carbons have been prepared from waste CDs and DVDs by carbonization and subsequent activation with either KOH or CO2. The resulting activated carbons had specific surface area in the range of 500-2240 m2 g-1, total pore volume in the range of 0.18-1.36 cm3 g-1, volume of micropores and small mesopores (w < ∼2.9 nm) in the range of 0.17-1.25 cm3 g-1, and volume of small micropores (w < ∼1.2 nm) in the range of 0.14-0.71 cm3 g-1. Both KOH and CO2 activation resulted in 5-45-fold improvement in the structural properties, depending on the conditions used. The resulting carbons showed good adsorption properties toward carbon dioxide, hydrogen, and benzene. The best uptakes for these adsorptives were 5.8 mmol g-1 of CO2 at 0 °C and 800 mmHg, 3.3 mmol g-1 of CO2 at 25 °C and 850 mmHg, 13.9 mmol g-1 of H2 at -196 °C and 850 mmHg, and 15.4 mmol g-1 of C6H6 at 20 °C and saturation pressure. The excellent adsorption properties of the prepared carbons render them as potential adsorbents in CO2 capture and storage, VOCs adsorption/separation, and hydrogen storage. © 2015 American Chemical Society.


PubMed | Military Institute of Chemistry and Radiometry and Military University of Technology
Type: | Journal: Talanta | Year: 2015

The subject of the work is the use of differential mobility spectrometry (DMS) for the detection of chemical warfare agents (CWA). Studies were performed for mustard gas, i.e., bis(2-chloroethyl)sulfide (HD), sarin, i.e., O-isopropyl methylphosphonofluoridate (GB) and methyl salicylate (MS) used as test compounds. Measurements were conducted with two ceramic DMS analyzers of different constructions allowing the generation of an electric field with an intensity of more than 120 Td. Detector signals were measured for positive and negative modes of operation in a temperature range from 0 to 80 C. Fragmentations of ions containing analyte molecules were observed for all tested compounds. The effective temperatures of fragmentation estimated on the basis of dispersion plots were equal from about 148 C for GB to 178 C for MS. It was found that values of separation voltage (SV) and compensation voltage (CV) at which the fragmentation of sample ions is observed may be the parameters improving the certainty of detection for different analytes. The DMS analyzers enabling the observation of ion fragmentation can be successfully used for effective CWA detection.


Pawlik-Skowronska B.,Joseph W. Jones Ecological Research Center | Pawlik-Skowronska B.,Lublin University of Life Sciences | Kornijow R.,Lublin University of Life Sciences | Kornijow R.,Polish National Marine Fisheries Research Institute | And 2 more authors.
Polish Journal of Ecology | Year: 2010

Recent history of numerous lakes is, among others, a consequence of anthropogenic activity that led to water eutrophication and excessive phytoplankton development. In nutrient- rich lakes both biomass of cyanobacteria and cyanotoxins, that may have a substantial impact on aquatic biocenoses, are present not only in water column but also in the bottom sediments. This study demonstrates vertical distribution of microcystins (MC) traces in sediments of two eutrophic lakes. one phytoplankton/macrophyte-dominated and the other phytoplankton-dominated. The sediments (1-40/50 cm depth) were sampled from central part of lakes and content of MC traces was determined by means of GC-MS in 1cm core slices. In the sediment profile (1-40 cm depth) of the phytoplankton/ macrophyte-dominated lake the MC contents ranged from 0.011 in deep layer (35 cm) to 0.910 μg equival. MC-LR g-1 d.w. in the surface layer (1 cm) and indicated gradual increase in eutrophication. connected with mass development of cyanobacteria over time. In phytoplanktondominated lake, MC contents (0.0-0.335 μg equival. MC-LR g-1 d.w.) oscillated through the core (1- 50 cm depth) and were relatively similar in older, deeper (20-50 cm) and younger (1-20 cm) layers what suggests long-lasting but variable intensity of cyanobacteria mass development. The obtained results indicate that traces of microcystins persist and are detectable for several dozens years not only in surface but also in deep sediment layers of lakes affected by former cyanobacterial blooms. They seem to be a reliable tool to follow eutrophication and its consequence. excessive development of cyanobacteria in the past time.


Maziejuk M.,Military Institute of Chemistry and Radiometry | Lisowski W.,Military Institute of Chemistry and Radiometry | Szyposzynska M.,Military Institute of Chemistry and Radiometry | Sikora T.,Military Institute of Chemistry and Radiometry | Zalewska A.,Military Institute of Chemistry and Radiometry
Solid State Phenomena | Year: 2015

Ion mobility spectrometry (IMS) is a technique used for the detection of chemical warfare agents (CWA), drugs, toxic industrial compounds (TIC), and explosives, when rapid detection should be performed (from a few to several seconds) for trace amounts of these substances. An important development of IMS technology is differential ion mobility spectrometry (DMS). DMS is also known as Field Asymmetric Waveform Ion Mobility Spectrometry (FAFMS). Detection possibilities of apparatus using the DMS method are based on the occurrence of the different mobilities of ions (K) in the alternating electric field. This dependence is characterized by the alpha function (α).This presentation shows methods and examples of the identification of chosen substances. The results for the dependence of coefficient α are specific for different types of substances. This specificity is used to identify vapours and gases. © (2015) Trans Tech Publications, Switzerland.


Zalewska A.,Military Institute of Chemistry and Radiometry | Sikora T.,Military Institute of Chemistry and Radiometry | Buczkowska A.,Military Institute of Chemistry and Radiometry
Proceedings - International Carnahan Conference on Security Technology | Year: 2014

In the past few years terrorism became one of the biggest threat for the public life and that why in now days one of most important civilization problems is to guarantee safety for the civilians. Most often occurring form of terrorism is usage of explosives, which result is definitely greater number of casualties per year than in case of use biological, chemical or even radiological substances. Explosives for the reason that are easy to reach, have wide and specific range of use, belong to the group of substances widely used in military operations as well as in acts of terrorism. Because of this it is crucial to effective and fast detection even in traces amount, what is directly connected with necessity providing analytical apparatus using technical novelties. There are many known techniques used for explosives detection but diverse places and ways of their use as well as requirement of really low detection limit allowing for detection on the 'dog's nose' level are reason for their continues improvement. One of the methods used for detection of traces amount of explosives is differential ion mobility spectrometry (DMS) which allows for detection of very low concentration analyzed substances. In Military Institute of Chemistry and Radiometry was made portable contamination signaling device (PRS-1) used for detection and identification wide range of chemical substances. PRS-1 was constructed based on the technique of gluing ceramic tiles and technology of depositing sensor electrodes on them. It is designed for the detection of chemical warfare agents, and initial testing of the detection explosives yielded positive results and form the basis for the concept of further research. Innovative solutions applied to the device PRS-1 cause that its technical parameters are very high - one of the best in the world. © 2014 IEEE.


PubMed | Military Institute of Chemistry and Radiometry and Wroclaw University of Technology
Type: | Journal: Talanta | Year: 2016

Benzene, toluene and xylene (BTX compounds) are chemicals of greatest concern due to their impact on humans and the environment. In many cases, quantitative information about each of these compounds is required. Continuous, fast-response analysis, performed on site would be desired for this purpose. Several methods have been developed to detect and quantify these compounds in this way. Methods vary considerably in sensitivity, accuracy, ease of use and cost-effectiveness. The aim of this work is to show that differential ion mobility spectrometry (DMS) may be applied for determining concentration of BTX compounds in humid air. We demonstrate, this goal is achievable by applying multivariate analysis of the measurement data using partial least squares (PLS) regression. The approach was tested at low concentrations of these compounds in the range of 5-20 ppm and for air humidity in a range 0-12 g/kg. These conditions correspond to the foreseeable application of the developed approach in occupational health and safety measurements. The average concentration assessment error was about 1 ppm for each: benzene, toluene and xylene. We also successfully determined water vapor content in air. The error achieved was 0.2 g/kg. The obtained results are very promising regarding further development of DMS technique as well as its application.

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