scholarly journals Development of Potentiometric Sensors for C2H4 Detection

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2992 ◽  
Author(s):  
Fidel Toldra-Reig ◽  
Jose Serra
Keyword(s):  
Electrode Materials ◽  
Reference Electrode ◽  
Promising Material ◽  
Potentiometric Sensors ◽  
Cross Sensitivity ◽  
Working Electrode ◽  
Polycyclic Aromatic ◽  
High Concentrations ◽  
Ion Conducting ◽  
The Individual

Gas exhaust emissions in vehicles are increasingly restrictive in EU and USA. Diesel engines are particularly affected by limitation in hydrocarbons and NOx concentrations. This work presents a screening of working electrode materials to develop a potentiometric sensor, with the most promising material to detect being C2H4 at 550 °C. The device consists of a dense 8YSZ (8 mol% Y2O3 stabilized ZrO2) disk as oxide-ion conducting electrolyte, whereas platinum is screen-printed in the back face as reference electrode. As working electrode, several materials such as Fe0.7Cr1.3O3, ZnCr2O4, Fe2NiO4, La0.8Sr0.2CrO3−δ (LSC), La0.8Sr0.2MnO3 (LSM), and NiO+5%wt Au were tested to detect C2H4. Sensor voltage was measured for several concentrations of C2H4 and CO as these are two of the major oxidizable compounds in a diesel exhaust gas. Fe0.7Cr1.3O3 was selected as the most promising material because of its response to C2H4 and CO. Not only is the response to the individual analytes important, but the C2H4 cross-sensitivity toward CO is also important. Fe0.7Cr1.3O3 showed a good performance to C2H4, with low cross-sensitivity to CO. In addition, when 0.16 ppm of phenanthrene is added, the sensor still has a slightly better response to C2H4 than to CO. Nevertheless, the sensor exposure to high concentrations (>85 ppm) of polycyclic aromatic hydrocarbons led to signal saturation. On the other hand, the operation in wet conditions induces lower sensor sensitivity to C2H4 and higher cross-sensitivity toward CO increase, i.e., the sensor response becomes similar for C2H4 and CO.

scholarly journals Photoelectric current as a highly sensitive readout for potentiometric sensors

2020 ◽  
Vol 56 (27) ◽  
pp. 3879-3882 ◽  
Author(s):  
Xu Hun ◽  
Xiaoli Xiong ◽  
Jiawang Ding ◽  
Wei Qin
Keyword(s):  
Reference Electrode ◽  
Ion Selective Electrode ◽  
Potentiometric Sensors ◽  
Polymeric Membrane ◽  
Selective Electrode ◽  
Photoelectric Current ◽  
Working Electrode ◽  
Highly Sensitive

The photocurrent at a working electrode coated with a ZnSe/r-GO composite can be modulated by a polymeric membrane ion-selective electrode that works as a reference electrode.

Potential Contribution of Nutrients and Polycyclic Aromatic Hydrocarbons from the Creeks of Cootes Paradise Marsh

1996 ◽  
Vol 31 (3) ◽  
pp. 485-504 ◽  
Author(s):  
Patricia Chow-Fraser ◽  
Barb Crosbie ◽  
Douglas Bryant ◽  
Brian McCarry
Keyword(s):  
Aromatic Hydrocarbons ◽  
Laboratory Experiments ◽  
Dry Weight ◽  
Common Source ◽  
Potential Contribution ◽  
Nitrogen And Phosphorus ◽  
Engine Combustion ◽  
Polycyclic Aromatic ◽  
High Concentrations ◽  
Derivatives Of

Abstract During the summer of 1994, we compared the physical and nutrient characteristics of the three main tributaries of Cootes Paradise: Spencer, Chedoke and Borer’s creeks. On all sampling occasions, concentrations of CHL α and nutrients were always lowest in Borer’s Creek and highest in Chedoke Creek. There were generally 10-fold higher CHL α concentrations and 2 to 10 times higher levels of nitrogen and phosphorus in Chedoke Creek compared with Spencer Creek. Despite this, the light environment did not differ significantly between Spencer and Chedoke creeks because the low algal biomass in Spencer Creek was balanced by a relatively high loading of inorganic sediments from the watershed. Laboratory experiments indicated that sediments from Chedoke Creek released up to 10 µg/g of soluble phosphorus per gram (dry weight) of sediment, compared with only 2 µg/g from Spencer Creek. By contrast, sediment samples from Spencer Creek contained levels of polycyclic aromatic hydrocarbon that were as high as or higher than those from Chedoke Creek, and much higher than those found in Borer’s Creek. The distribution of normalized PAH concentrations suggests a common source of PAHs in all three tributaries, most likely automobile exhaust, since there were high concentrations of fluoranthene and pyrene, both of which are derivatives of engine combustion.

scholarly journals Environmental DNA preserved in marine sediment for detecting jellyfish blooms after a tsunami

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mizuki Ogata ◽  
Reiji Masuda ◽  
Hiroya Harino ◽  
Masayuki K. Sakata ◽  
Makoto Hatakeyama ◽  
...  
Keyword(s):  
Marine Sediment ◽  
Oil Spills ◽  
Sediment Cores ◽  
Environmental Dna ◽  
Target Species ◽  
Tank Experiment ◽  
Polycyclic Aromatic ◽  
Flow Through ◽  
High Concentrations ◽  
One Year

AbstractEnvironmental DNA (eDNA) can be a powerful tool for detecting the distribution and abundance of target species. This study aimed to test the longevity of eDNA in marine sediment through a tank experiment and to use this information to reconstruct past faunal occurrence. In the tank experiment, juvenile jack mackerel (Trachurus japonicus) were kept in flow-through tanks with marine sediment for two weeks. Water and sediment samples from the tanks were collected after the removal of fish. In the field trial, sediment cores were collected in Moune Bay, northeast Japan, where unusual blooms of jellyfish (Aurelia sp.) occurred after a tsunami. The samples were analyzed by layers to detect the eDNA of jellyfish. The tank experiment revealed that after fish were removed, eDNA was not present in the water the next day, or subsequently, whereas eDNA was detectable in the sediment for 12 months. In the sediment core samples, jellyfish eDNA was detected at high concentrations above the layer with the highest content of polycyclic aromatic hydrocarbons, reflecting tsunami-induced oil spills. Thus, marine sediment eDNA preserves a record of target species for at least one year and can be used to reconstruct past faunal occurrence.

scholarly journals The Composition of Cigarette Smoke. An Historical Perspective of Several Polycyclic Aromatic Hydrocarbons

2009 ◽  
Vol 23 (6) ◽  
pp. 384-410 ◽  
Author(s):  
A Rodgman ◽  
LC Cook
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Melting Point ◽  
Cigarette Smoke ◽  
Aromatic Hydrocarbons ◽  
Tobacco Smoke ◽  
Individual Component ◽  
Complex Mixtures ◽  
Polycyclic Aromatic ◽  
The Individual ◽  
Cigarette Mainstream Smoke

AbstractBecause of the significant advancements in fractionation, analytical, and characterization technologies since the early 1960s, hundreds of components of complex mixtures have been accurately characterized without the necessity of actually isolating the individual component. This has been particularly true in the case of the complex mixtures tobacco and tobacco smoke. Herein, an historical account of a mid-1950 situation concerning polycyclic aromatic hydrocarbons (PAHs) in cigarette smoke is presented. While the number of PAHs identified in tobacco smoke has escalated from the initial PAH, azulene, identified in 1947 to almost 100 PAHs identified by late 1963 to more than 500 PAHs identified by the late 1970s, the number of PAHs isolated individually and characterized by several of the so-called classical chemical means (melting point, mixture melting point, derivative preparation and properties) in the mid-1950s and since is relatively few, 14 in all. They were among 44 PAHs identified in cigarette mainstream smoke and included the following PAHs ranging from bicyclic to pentacyclic: Acenaphthylene, 1,2-dihydroacenaphthylene, anthracene, benz[a]anthracene, benzo[a]pyrene, chrysene, dibenz[a, h]anthracene, fluoranthene, 9H-fluorene, naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, phenanthrene, and pyrene. One of them, benzo[a]pyrene, was similarly characterized in another study in 1959 by Hoffmann.

scholarly journals Hazard indicators of urban soil contamination with polycyclic hydrocarbons on the example of monitoring results of the RUDN campus

2020 ◽  
Vol 28 (2) ◽  
pp. 112-130
Author(s):  
Margarita M. Redina ◽  
Alexander P. Khaustov ◽  
Xiangkai Li ◽  
Zhandos D. Kenzhin ◽  
Polina Yu. Silaeva
Keyword(s):  
Soil Contamination ◽  
Urban Areas ◽  
Carcinogenic Risk ◽  
Individual Characteristics ◽  
Forest Park ◽  
Pollution Levels ◽  
Sources Of Pollution ◽  
Functional Zones ◽  
Polycyclic Aromatic ◽  
The Individual

The characteristics of the hazard of urban soils pollution by polycyclic aromatic hydrocarbons (PAHs) are considered: naphthalene (Naph), anthracene (An), phenanthrene (Phen), pyrene (Py), fluoranthene (Flu), chrysene (Chr), benzo(a)anthracene (BaA), benzo[a]pyrene (BaP), benzo[b]fluoranthene (BbFlu), benzo[k]fluoranthene (BkFlu), dibenzo[ah]antracene (DBa), benzo[ghi]perylene (Bghi), indeno[1,2,3-c,d]pyrene). On the example of monitoring data on the RUDN University campus and the adjacent South-West Forest Park, modern approaches to assessing the hazard of pollution levels and the environmental risk of soil pollution are demonstrated: RQ indicators, total relative toxicity in comparison to BaP, carcinogenic risk, behavior of the representative PAHs. On the basis of a critical analysis of the pollution indicators, the optimal approaches to assessing the danger of the presence of polyarenes in the soils of urban areas are demonstrated. The leading sources of pollution (influence of vehicles) were identified. Different levels of environmental hazard of polyarene soil contamination in different functional zones of the analyzed territory are demonstrated: relatively clear territory in the middle zone of the park and a specific configuration of the pollution field on the rest of the territory. The necessity of developing ecosystem standards for urban natural complexes is justified, taking into account the individual characteristics of soils, the role of soil microbiota, the specificity of the use of the territory and the characteristics of pollution sources.

scholarly journals Design and development of a multichannel potentiometer for monitoring an electrode array and its application in flow analysis

2002 ◽  
Vol 24 (4) ◽  
pp. 105-110 ◽  
Author(s):  
Jarbas J. R. Rohwedder ◽  
Celio Pasquini ◽  
Ivo M. Raimundo, Jr. ◽  
M. Conceiçao ◽  
B. S. M. Montenegro ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Flow Analysis ◽  
Reference Electrode ◽  
Electrode Array ◽  
Ion Selective Electrodes ◽  
Electrode Arrays ◽  
Figures Of Merit ◽  
Flow Through ◽  
The Individual ◽  
Intense Signal

A versatile potentiometer that works with electrode arrays in flow injection and/or monosegmented flow systems is described. The potentiometer is controlled by a microcomputer that allows individual, sequential multiplexed or random accesses to eight electrodes while employing only one reference electrode. The instrument was demonstrated by monitoring an array of seven flow-through ion-selective electrodes for Ag+and for three electrodes for Cl-, Ca2+and K+. The figures of merit of the individual and multiplexed (summed) readings of the electrode array were compared. The absolute standard deviation of the measurements made by summing the potential of two or more electrodes was maintained constant, thus improving the precision of the measurements. This result shows that an attempt to combine the signals of the electrodes to produce a more intense signal in the Hadamard strategy is feasible and accompanied by a proportional improvement in the precision of individual measurements. The preliminary tests suggest that the system can allow for 270 determinations per hour, with a linear range from1.0×10−2to1.0×10−4mol l-1for the three di¡erent analytes. Detection limits were estimated as3.1×10−5,3.0×10−6and1.0×10−5mol l-1for Cl-, Ca2+and K+, respectively.

scholarly journals Overview and Insights into Carbapenem Allergy

Pharmacy ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 110 ◽  
Author(s):  
Yuman Lee ◽  
Nicole Bradley
Keyword(s):  
Case Reports ◽  
Review Article ◽  
Limited Data ◽  
Substantial Impact ◽  
Cross Sensitivity ◽  
Search Terms ◽  
Incidence Risk ◽  
Pubmed Search ◽  
The Individual ◽  
Insight Into

Understanding antibiotic allergies and the risk of cross-sensitivity between and within antibiotic classes can have a substantial impact on patient care. The purpose of this review article is to provide insight into carbapenem allergies, describing the overall incidence, risk factors, and in-class cross-sensitivity. A PubMed search was conducted using the following search terms: carbapenem, allergy, cross-sensitivity, incidence, imipenem/cilastatin, meropenem, ertapenem, and doripenem. Article bibliographies and relevant drug monographs were also reviewed. The overall reported incidence of carbapenem allergy is 0.3%–3.7%. Risk of cross-sensitivity between penicillins and carbapenems is less than 1% in patients with a positive penicillin skin test. Data on cross-sensitivity between cephalosporins and carbapenems are limited; however, the risk appears to also be low. No clinical studies have described cross-sensitivity between the carbapenem agents thus far. The limited data available from case reports demonstrates a lack of cross-sensitivity between the individual carbapenems, suggesting that an alternative carbapenem may cautiously be used in patients with a reported carbapenem allergy.

scholarly journals Wearable Potentiometric Sensors for Medical Applications

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 363 ◽  
Author(s):  
María Cuartero ◽  
Marc Parrilla ◽  
Gaston Crespo
Keyword(s):  
Sport Performance ◽  
Medical Utilization ◽  
Potentiometric Sensors ◽  
Sensor Calibration ◽  
Medical Applications ◽  
Sample Collection ◽  
Medical Settings ◽  
Wide Range ◽  
The Individual

Wearable potentiometric sensors have received considerable attention owing to their great potential in a wide range of physiological and clinical applications, particularly involving ion detection in sweat. Despite the significant progress in the manner that potentiometric sensors are integrated in wearable devices, in terms of materials and fabrication approaches, there is yet plenty of room for improvement in the strategy adopted for the sample collection. Essentially, this involves a fluidic sampling cell for continuous sweat analysis during sport performance or sweat accumulation via iontophoresis induction for one-spot measurements in medical settings. Even though the majority of the reported papers from the last five years describe on-body tests of wearable potentiometric sensors while the individual is practicing a physical activity, the medical utilization of these devices has been demonstrated on very few occasions and only in the context of cystic fibrosis diagnosis. In this sense, it may be important to explore the implementation of wearable potentiometric sensors into the analysis of other biofluids, such as saliva, tears and urine, as herein discussed. While the fabrication and uses of wearable potentiometric sensors vary widely, there are many common issues related to the analytical characterization of such devices that must be consciously addressed, especially in terms of sensor calibration and the validation of on-body measurements. After the assessment of key wearable potentiometric sensors reported over the last five years, with particular attention paid to those for medical applications, the present review offers tentative guidance regarding the characterization of analytical performance as well as analytical and clinical validations, thereby aiming at generating debate in the scientific community to allow for the establishment of well-conceived protocols.

scholarly journals Composition and mass size distribution of nitrated and oxygenated aromatic compounds in ambient particulate matter from southern and central Europe – implications for origin

2019 ◽  
Author(s):  
Zoran Kitanovski ◽  
Pourya Shahpoury ◽  
Constantini Samara ◽  
Aristeidis Voliotis ◽  
Gerhard Lammel
Keyword(s):  
Particulate Matter ◽  
Size Fraction ◽  
Ambient Air ◽  
Water Soluble ◽  
Atmospheric Particulate Matter ◽  
Polycyclic Aromatic ◽  
Mass Size ◽  
Water Soluble Organic Carbon ◽  
Soluble Organic Carbon ◽  
The Individual

Abstract. Nitro-monoaromatic hydrocarbons (NMAHs), such as nitrocatechols, nitrophenols and nitrosalicylic acids, are important constituents of atmospheric particulate matter (PM) water soluble organic carbon (WSOC) and humic-like substances (HULIS). Nitrated and oxygenated derivatives of polycyclic aromatic hydrocarbons (NPAHs, OPAHs) are toxic and ubiquitous in the ambient air; due to their light absorption properties, together with NMAHs they are part of aerosol brown carbon (BrC). We investigated the winter concentrations of these substance classes in size-resolved particulate matter (PM) from two urban sites in central and southern Europe, i.e. Mainz (MZ), Germany and Thessaloniki (TK), Greece. ∑11NMAH concentrations in PM10 and total PM were 0.51–8.38 and 12.1–72.1 ng m−3 at MZ and TK site, respectively, whereas ∑8OPAHs were 47–1636 and 858–4306 pg m−3, and ∑17NPAHs were ≤ 90 and 76–578 pg m−3, respectively. NMAHs and the water-soluble OPAHs contributed 0.4 and 1.8 %, and 0.0001 and 0.0002 % to the HULIS mass, at MZ and TK, respectively. The mass size distributions of the individual substances generally peaked in the smallest or second smallest size fraction i.e.,

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