Low Concentrations Of Acetone Research Articles

Acetone sensing properties and mechanism of nano-LaFeO3 thick-films

LaFeO3 nanocrystalline powders prepared by sol–gel method with annealing at 800°C for 4h can sensitively detect low concentration of acetone. When exposed to 0.5ppm acetone, the response of LaFeO3 thick film at 260°C is 2.068 with response time of 62s and recovery time of 107s, respectively. The possible acetone sensing mechanisms for LaFeO3 sensor are investigated with first principles calculations. Calculated results demonstrate that acetone could release electrons to the surface of LaFeO3 (010) pre-adsorbed with oxygen species O− and O2−. The acetone molecule reacts with oxygen species in the following ways: (1) adsorbs on oxygen species O− or (2) replaces of the weakly pre-adsorbed oxygen species O2− on Fe site, accompanying the formation of oxygen molecule. These above two processes may play important roles in acetone sensing for LaFeO3. We also find that the acetone molecule can be directly adsorbed on Fe site, transferring some electrons to the LaFeO3 (010) surface. The latter processes may also provide additional contribution to acetone sensing.

Investigation of hybrid plasma-catalytic removal of acetone over CuO/γ-Al2O3 catalysts using response surface method

In this work, plasma-catalytic removal of low concentrations of acetone over CuO/γ-Al2O3 catalysts was carried out in a cylindrical dielectric barrier discharge (DBD) reactor. The combination of plasma and the CuO/γ-Al2O3 catalysts significantly enhanced the removal efficiency of acetone compared to the plasma process using the pure γ-Al2O3 support, with the 5.0 wt% CuO/γ-Al2O3 catalyst exhibiting the best acetone removal efficiency of 67.9%. Catalyst characterization was carried out to understand the effect the catalyst properties had on the activity of the CuO/γ-Al2O3 catalysts in the plasma-catalytic reaction. The results indicated that the formation of surface oxygen species on the surface of the catalysts was crucial for the oxidation of acetone in the plasma-catalytic reaction. The effects that various operating parameters (discharge power, flow rate and initial concentration of acetone) and the interactions between these parameters had on the performance of the plasma-catalytic removal of acetone over the 5.0 wt% CuO/γ-Al2O3 catalyst were investigated using central composite design (CCD). The significance of the independent variables and their interactions were evaluated by means of the Analysis of Variance (ANOVA). The results showed that the gas flow rate was the most significant factor affecting the removal efficiency of acetone, whilst the initial concentration of acetone played the most important role in determining the energy efficiency of the plasma-catalytic process.

A gas sensor made from a graphite paper with a nanotube film

A technique for obtaining gas sensor samples from graphite paper with a nanotube film is described. Current-induced annealing of the graphite paper and additional evaporation of a nanotube graphite film in a hydrogen atmosphere are combined in the developed technique. The current−voltage characteristics of the samples have been measured at room temperature in air, in vacuum, and at low concentrations of NH3, ethanol, and acetone. Experiments demonstrate that these samples containing carbon multiwall nanotubes can be used as a gas sensor to detect the presence of NH3 and acetone. They are characterized by high sensitivity and selectivity, fast response, restoration, and stability of the characteristics. The estimated sensor sensitivities to NH3, acetone, and ethanol at a current of 96.8 mA are ~15, ~12, and ~1 mV/Torr, respectively. Their sensitivity is determined by the difference in the behavior of their current−voltage characteristics under exposure to NH3, ethanol, and acetone. The sensor features fast response (5–20 s) and restoration (within 5 min, restoration to the initial state before the exposure to NH3 is 100.2%), as well as the stability of its characteristics (the pressure ranges from 1 × 10–6 to 760 Torr).

Optical Acetone Vapor Sensors Based on Chiral Nematic Liquid Crystals and Reactive Chiral Dopants

Accurate monitoring of exposure to organic vapors, such as acetone, is an important part of maintaining a safe working environment and adhering to long‐ and short‐term exposure limits. Here, a novel acetone vapor detection system is described based on the use of a reactive chiral dopant in a nematic liquid crystal thin film, which can accurately monitor the total exposure over a given time frame through changes in the reflection band of the film. It is found that films exposed to 1000 parts per million by volume (ppmv) of acetone vapor for 2 h exhibit a shift in reflection band of 12 nm, with smaller shifts observed at lower concentrations of acetone. Such sensors have potential applications in industrial hygiene.

An unnatural death by propan-1-ol and propan-2-ol

A fatality of an inpatient ingesting a disinfectant containing ethanol, propan-1-ol, and propan-2-ol is reported. The alleged survival time was about 1h. Major findings at autopsy were an extended hemorrhagic lung edema, an edematous brain, and shock kidneys. Concentrations of alcohols and acetone, a major metabolite of propan-2-ol, were determined from body fluids (blood from the heart and the femoral vein, urine, gastric contents) and tissues (brain, muscle, liver, kidneys, lungs) by headspace/gas chromatography using 2-methylpropan-2-ol as the internal standard. All samples investigated were positive for propan-1-ol, propan-2-ol, ethanol, and acetone except stomach contents, where acetone was not detectable. The low concentration of acetone compared to propan-2-ol likely supports the short survival time. The concentration ratios estimated from the results are in accordance with the physico-chemical properties of the particular alcohols, their different affinities towards alcohol dehydrogenase as well as their interdependence during biotransformation. Autopsy did not reveal the cause of death. According to the few published data, blood concentrations of 1.44 and 1.70mg/g of propan-2-ol and propan-1-ol, respectively, are considered sufficient to have caused the death. This case also points to the need to restrict access to antiseptic solutions containing alcohols in wards with patients at risk.

Occurrence of acetone concentrations>0.10g/L in post-mortem femoral blood and association with ethanol and isopropanol concentrations

Summary The analysis of volatiles in post-mortem blood by gas chromatography sometimes shows the presence of acetone at concentrations exceeding 0.10 g/L, which is the analytical cut-off used in many laboratories. Whether these results reflect ante-mortem ingestion of isopropanol and subsequent oxidation to acetone or if the deceased suffered from a metabolic disorder (diabetes and/or ketoacidosis) is not always obvious. To throw more light on this question, we made a retrospective survey of ∼45,000 post-mortem blood samples and found that in 1366 cases (3%) acetone concentrations were > 0.10 g/L; mean (median) and highest 0.26 g/L (0.19 g/L) and 2.4 g/L, respectively. Of these 1366 blood samples, there were 256 (19%) that contained isopropanol at mean (median) and highest concentrations of 0.30 g/L (0.15 g/L) and 3.1 g/L. Blood-ethanol was positive (> 0.10 g/L) in 500 cases (37%) and the mean (median) and highest concentrations were 1.1 g/L (0.68 g/L) and 6.2 g/L. The concentrations of acetone and isopropanol in blood were highly correlated, r = 0.52 ( P r = −0.16) and ethanol vs isopropanol ( r = −0.04). Relatively low concentrations of acetone in blood (> 0.10 g/L but + biochemical reaction. Analytical results showing higher concentrations of acetone in blood (> 0.30 g/L), with or without isopropanol present, are more likely caused by ante-mortem ingestion of isopropanol and/or acetone for intoxication purposes.

Electrospinning synthesis of vanadium–TiO2–carbon composite nanofibrous membranes as effective catalysts for the complete oxidation of low-concentration acetone

TiO2–carbon and vanadium–TiO2–carbon composite nanofibrous membranes were synthesized through electrospinning and investigated for the complete oxidation of low-concentration acetone. The novel nanofibrous membranes were characterized through various techniques, including TG/DSC, SEM-EDX, HRTEM, XRD, N2 sorption, XPS, NH3-TPD, and H2-TPR analyses. Introduction of vanadium at an appropriate amount enhances the catalytic performance in complete acetone oxidation. The best result was obtained with 10V–TiC nanofibers that contain 10wt.% vanadium. Furthermore, the 10V–TiC nanofibers displayed higher activity than that of the V2O5/TiO2 reference catalyst prepared by impregnation method. Characterization results indicate that these fibers exhibit a typical nanofibrous morphology. Vanadium incorporation accelerates the decomposition of the gel precursor nanofibers and causes variations in textural properties, surface chemistry, acidity, and reducibility. The high porosity of the nanofibrous structure, abundant adsorbed oxygen species on the surface, strong acidity, and reducibility enhance the catalytic performance.

Three-dimensional ordered ZnO–CuO inverse opals toward low concentration acetone detection for exhaled breath sensing

A series of three-dimensional (3D) ordered ZnO–CuO inverse opals (IO) were synthesized by a simply polymethylmethacrylate (PMMA) template method and characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), Xray diffractometer, and Xray photoelectron spectroscopy (XPS) techniques. The performance of the ZnO–CuO IO sensors to diabetes biomarker (acetone gas) toward exhaled breath was systemically studied. The results indicate that the sensing properties of the ZnO–CuO IO sensors to very low acetone concentration are enhanced compared with that of the pure ZnO and CuO IO sensors, depending strongly on the ZnO and CuO molar ratio. The IO sensor with atom ratio of Zn/Cu=1:1 is the optimal one, the corresponding response is 1.4–2.4 times higher than the other IO gas sensors in this work and the detection limit is as low as 100ppb. And more, it shows good performance to acetone under quite high humidity. The enhanced sensing performance can be attributed to the formation of p–n heterojunctions and the well-constructed 3D IO structure. The excellent sensing performance indicates that 3D ZnO–CuO IO hybrid composites are a promising functional material to actual application in monitoring and detecting diabetes in a noninvasive and more accurate way.

The effect of acetone on the dynamics of temporal oscillations and waves in the ruthenium-catalyzed Belousov-Zhabotinsky reaction.

The effect of acetone on temporal oscillations and spatio-temporal patterns occurring in the ruthenium-catalyzed Belousov-Zhabotinsky (BZ) reaction was investigated in a closed batch system. The periods of temporal oscillations and waves significantly decrease with increasing acetone concentration. At low concentrations of acetone (0.01-0.05 M), regular wave patterns are observed with prolonged lifetimes of both temporal oscillations and waves. However, for higher concentrations (0.10-1.00 M acetone), the lifetime is shortened and irregular patterns are formed. The photosensitivity of waves of the Ru(bpy)3(2+)-catalyzed BZ reaction remains the same for all acetone concentrations. The results are discussed in terms of the proposed reaction mechanism.

Lidar/DIAL detection of acetone at 3.3 μm by a tunable OPO laser system

In this paper we report, for the first time to our knowledge, on lidar/DIAL detection of acetone vapors at 3.3 μm by means of an optical parametric tunable laser system. After a preliminary spectroscopic study in an absorption cell, the feasibility of a differential absorption (DIAL) lidar for the detection of acetone vapors has been investigated in the laboratory, simulating the experimental conditions of a field campaign. Having in mind measurements in a real scenario, a study of possible atmospheric intereferents has been performed, looking for all known compounds that share acetone IR absorption in the spectral band selected for its detection. Possible interfering species from urban and industrial atmospheres were investigated and limits of acetone detection in both environments were identified. This study confirmed that a lidar system can detect a low concentration of acetone at considerable distances.

Parasiticidal effects of Morus alba root bark extracts against Ichthyophthirius multifiliis infecting grass carp

Ichthyophthirius multifiliis (Ich), an important fish parasite, can cause significant losses in aquaculture. To find efficacious drugs to control Ich, the root bark of white mulberry Morus alba was evaluated for its antiprotozoal activity. Bark was powdered and extracted with 1 of 5 organic solvents: petroleum ether, chloroform, ethyl acetate, acetone, or methanol. The extracts were concentrated, dissolved in 0.1% (v/v) DMSO, and used for anti-Ich trials. Acetone and ethyl acetate extracts significantly reduced the survival of Ich tomonts and theronts. In vitro, acetone extract at 25 mg l-1 killed all non-encysted tomonts, at 50 mg l-1 eradicated all encysted tomonts, and at 8 mg l-1 caused mortality of all theronts. Ethyl acetate extract at 50 mg l-1 eliminated all non-encysted tomonts, at 100 mg l-1 killed all encysted tomonts and terminated tomont reproduction, and at 8 mg l-1 killed all theronts. Low concentrations (2 and 4 mg l-1) of acetone and ethyl acetate extracts could not kill all theronts after 4 h exposure, but a significant decrease in theront infectivity was observed following 30 min of pretreatment with the extracts. The 96 h LC(50) values of acetone and ethyl acetate extracts to grass carp were 79.46 and 361.05 mg l-1, i.e. much higher than effective doses for killing Ich theronts (8 mg l-1 for both extracts) and non-encysted tomonts (12.5 and 25 mg l-1, respectively). Thus M. alba extract may be a potential new, safe, and efficacious drug to control Ich.

Plasma-catalytic removal of a low concentration of acetone in humid conditions

Gas humidity significantly affects the plasma-catalytic removal of acetone, while the use of catalysts reduces byproduct formation.

Electrochemical impedance characterisation of tungsten trioxide–polyaniline nanocomposites for room temperature acetone sensing

Composites of WO3 nanoparticles and water-soluble polyaniline (PANI) particles doped with dodecyl benzenesulphonic acid at different mass ratios were deposited onto interdigitated electrodes and characterised using electrochemical impedance spectroscopy in air and in acetone vapour. The nanocomposites displayed an approximate equivalent circuit model of a parallel resistance and small inductance due to the PANI and a constant phase element (CPE) due to the WO3. The contribution of the CPE increased with increased WO3 loading. The nanocomposites mostly displayed increases in their real impedance on exposure to acetone at frequencies below 1kHz, as well as a small increase in imaginary impedance. However, low WO3 loadings and low acetone concentrations resulted in decreases in film resistance. This effect is due to the balance of charge carriers in the film. The resulting sensors were able to detect 10ppmv acetone at room temperature.

Porous spheres-like ZnO nanostructure as sensitive gas sensors for acetone detection

Porous spheres-like zinc oxide (ZnO) nanostructure was synthesized by electrospinning method followed by calcining. The microstructure and chemical composition were investigated with X-ray diffraction, energy dispersive spectroscopy, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmet–Teller method and X-ray photoelectron spectroscopy. The results showed that the porous spheres-like ZnO nanostructure with large specific surface area (22.6m2/g) was composed of ZnO nanoparticles of ∼40–80nm grain size and numerous oxygen species (O− and O2−) were adsorbed on the surface of ZnO nanoparticles. Meanwhile, the testing on gas sensing performance revealed that porous spheres-like ZnO nanostructure based sensor has an optimum operating temperature of 310°C, large resistance (1064kΩ), good stability for low concentration acetone (2ppm acetone at 310°C) and good selectivity at 310°C for acetone.

Thin‐Wall Assembled SnO2 Fibers Functionalized by Catalytic Pt Nanoparticles and their Superior Exhaled‐Breath‐Sensing Properties for the Diagnosis of Diabetes

AbstractHierarchical SnO2 fibers assembled from wrinkled thin tubes are synthesized by controlling the microphase separation between tin precursors and polymers, by varying flow rates during electrospinning and a subsequent heat treatment. The inner and outer SnO2 tubes have a number of elongated open pores ranging from 10 nm to 500 nm in length along the fiber direction, enabling fast transport of gas molecules to the entire thin‐walled sensing layers. These features admit exhaled gases such as acetone and toluene, which are markers used for the diagnosis of diabetes and lung cancer. The open tubular structures facilitated the uniform coating of catalytic Pt nanoparticles onto the inner SnO2 layers. Highly porous SnO2 fibers synthesized at a high flow rate show five‐fold higher acetone responses than densely packed SnO2 fibers synthesized at a low flow rate. Interestingly, thin‐wall assembled SnO2 fibers functionalized by Pt particles exhibit a dramatically shortened gas response time compared to that of un‐doped SnO2 fibers, even at low acetone concentrations. Moreover, Pt‐decorated SnO2 fibers significantly enhance toluene response. These results demonstrate the novel and practical feasibility of thin‐wall assembled metal oxide based breath sensors for the accurate diagnosis of diabetes and potential detection of lung cancer.

The sensing mechanism and detection of low concentration acetone using chitosan-based sensors

Abstract This paper aims to discuss the usage of chitosan film sensors to detect acetone concentrations in human breath, in order to precisely diagnose diabetes mellitus in patients. Acetone concentration in the breath varies from 0.3 to 0.9 ppm in healthy people to more than 1.8 ppm for diabetics. This makes acetone a suitable chemical marker for diabetes diagnosis. Therefore, the preliminary study on the electrical laboratory testing of the chitosan film sensor properties to acetone vapor-contaminated air in range of 0.1–100 ppm was carried out at room temperature (∼25–30 °C) in normal air. Our results suggested that the proposed acetone-based gas sensor can operate at room temperature with a high performance demonstrated by good response, recovery, stability and repeatability. This trouble free, painless and steadfast technique will improve the current gold standard in diagnosing diabetes, enabling quick and early detection.

Degradation of short chain polychlorinated paraffins by a new isolate: tests in pure culture and sewage sludge

AbstractBACKGROUNDShort chain chlorinated paraffins SCCPs are priority hazardous substances classified by the European Water Framework Directive and have been detected in sewage sludge of wastewater treatment plants worldwide. However, studies on the biodegradation of SCCPs presented in sewage sludge are very scarce.RESULTSIn this study, a bacterial strain that can utilize SCCPs as a sole source of carbon and energy was isolated from soil. This strain was identified as Pseudomonas sp. N35. The efficacy of SCCP degradation by strain N35 was tested in pure culture and sewage sludge microcosms containing 66.1 mg kg–1 SCCPs. The results showed that 57.5% of chloride was released into the medium as chloride ions in pure culture within 20 days. Mesophilic temperature and near‐neutral pH were most favorable for SCCP degradation. The addition of low concentrations of glucose, Tween‐80 and acetone (20 mg L–1) enhanced SCCP degradation. Bioaugmentation resulted in 73.4% removal of SCCPs in the sludge microcosm after 30 days of treatment.CONCLUSIONBioaugmentation with specific strains may be of great significance in bioremediation of SCCP‐containing sewage sludge.© 2012 Society of Chemical Industry

A Sub-ppm Acetone Gas Sensor for Diabetes Detection Using 10 nm Thick Ultrathin InN FETs

An indium nitride (InN) gas sensor of 10 nm in thickness has achieved detection limit of 0.4 ppm acetone. The sensor has a size of 1 mm by 2.5 mm, while its sensing area is 0.25 mm by 2 mm. Detection of such a low acetone concentration in exhaled breath could enable early diagnosis of diabetes for portable physiological applications. The ultrathin InN epilayer extensively enhances sensing sensitivity due to its strong electron accumulation on roughly 5–10 nm deep layers from the surface. Platinum as catalyst can increase output current signals by 2.5-fold (94 vs. 37.5 μA) as well as reduce response time by 8.4-fold (150 vs. 1,260 s) in comparison with bare InN. More, the effect of 3% oxygen consumption due to breath inhalation and exhalation on 2.4 ppm acetone gas detection was investigated, indicating that such an acetone concentration can be analyzed in air.

Poisoning of acetone to Pt and Au electrodes for electrooxidation of 2-propanol in alkaline medium

Running of direct 2-propanol fuel cell generates liquid acetone as the main product in the anode compartment. Its concentration continuously increases during cell operation. Its effect on the electrooxidation of 2-propanol at the anode catalyst deserves to be addressed. In this study, the influence of acetone concentration and reaction temperature on the electrooxidation of 2-propanol at Pt and Au electrode in alkaline electrolyte is investigated by cyclic voltammetry and chronoamperometry. The results show that the rate of 2-propanol electrooxidation at Pt and Au electrode is remarkably diminished with the increase of acetone concentration. When the concentration of acetone reaches 0.1molL−1, the oxidation current of 2-propanol at Pt and Au electrode decreases by around 50% and 30%, respectively. The effect of acetone can be attributed to its competitive adsorption with 2-propanol on electrodes surface, leading to the poison of electrodes. Increase of reaction temperature decreases the oxidation current of 2-propanol at Au electrode. Au electrode is more tolerant to acetone than Pt electrode at low acetone concentration. Results of this study suggest that new acetone insensitive electrocatalysts are needed for 2-propanol electrooxidation in alkaline electrolytes.

Lack of response in a marine pelagic community to short-term oil and contaminant exposure

Oil and contaminant inputs are co-occurring features of most estuaries and harbours in industrialised countries. However, there is limited knowledge as to how these different pressures interact. Oil may modulate the accumulation and effects of contaminants, and community response to contaminant stress would be expected to be coupled to food web structure. We performed an outdoor land-based 100-L microcosm experiments using natural coastal sea water in order to address these questions.Either mineral oil, emamectin (EMA; a pharmaceutical used in aquaculture and agriculture), or a combination was dosed to three replicate tanks for each treatment. Samples were taken at the start and each day of a four-day exposure period. For each sample, algal production and nutrients were quantified. Bacterial abundance was assessed by flow cytometry and the fate of emamectin investigated by filtration followed by extraction and LC/MS/MS analysis. Mesozooplankton were counted in samples taken at the end of the experiment.There were clear changes in chlorophyll a and bacterial numbers over the time course of the experiment in all treatments, but addition of oil, EMA or their combination did not alter nutrient concentrations, ecosystem components or the community structure compared to the control. There was however an unexplained apparent positive effect of low concentrations of acetone (0.005%) used as solvent in the mesocosms. Emamectin was predominantly found in the water phase at the end of the experiment with higher concentrations in both fractions of EMA–oil treatments compared to treatments with EMA only. The study shows that even high concentrations of the environmental stressors oil and emamectin may not have dramatic effects in a dynamic pelagic system over a four-day period, presumably indicating that longer exposure will be required for any effects through top-down processes to become evident.