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A novel method was developed for the rapid detection of heavy metals in firework solutions with high sensitivity and minimal pretreatment by enriching them with ethylenediaminetetraacetic acid (EDTA) reagent and analyzing them using microwave plasma torch mass spectrometry (MPT‐MS). Quantitative results showed that the limits of detection and quantification for heavy metals (Pb, Ba, Sr, and Ag) ranged from 0.05 to 0.25 and 0.38 to 0.71 μg·L−1, respectively. The linear dynamic ranges covered at least two orders of magnitude, with correlation coefficients exceeding 0.99. Fireworks from five regions in China were also analyzed quantitatively, detecting heavy metals including Pb, Ba, Sr, and Ag, with recovery rates ranging from 87.9% to 107.5%. Good separation between the firework samples from different regions was achieved by using element ratios and principal component analysis (PCA). These results from the preliminary study showed that the EDTA‐assisted MPT‐MS combined with PCA is a powerful tool for characterizing firework samples and tracing them back to their sources, which is valuable to effectively regulate and manage banned fireworks. [ABSTRACT FROM AUTHOR]

Cigarette smoke contains a large number of chemicals, including both flavor components and harmful substances. The mainstream smoke (MSS) generated by smoking is directly inhaled by individuals, making it crucial to establish an effective method for smoke detection and analysis. One promising technique for analyzing smoke is MPT‐MS (Microwave plasma torch mass spectrometry). This approach offers several advantages in accurately detecting the composition of cigarette smoke. By combining MPT‐MS with a smoke pumping device, we can achieve real‐time online detection of smoke components. We successfully detected 22 flavor compounds present in the smoke. These compounds contribute to the distinct taste of cigarettes. Moreover, we identified 2 polycyclic aromatic hydrocarbons (PAHs) in the smoke. PAHs are known carcinogens and are of great concern in terms of their potential health risks. The successful detection and identification of flavor compounds and PAHs using our method confirm the online detection capability of MPT‐MS. This approach provides an efficient and reliable means for analyzing the complex composition of cigarette smoke. By utilizing MPT‐MS, we can gain valuable insights into the chemical composition of cigarette smoke and can inform the development of strategies and policies aimed at reducing the harmful effects of smoking and protecting public health. [ABSTRACT FROM AUTHOR]

Plasma technology, relatively new in the fields of biomedicine, agriculture, and ecology, is the subject of intensive research as a prospective means of decontamination of various microorganisms (bacteria, viruses, and fungi). The objectives of the present study were to follow the effect of cold atmospheric plasma (CAP) treatment on in vitro grown plum plants (Prunus domestica L. 'Kyustendilska sinya' cv.) and the possibility of eradicating or inactivating plum pox virus (PPV) causing Sharka disease by CAP. The source tree is naturally co-infected by PPV (both M and D strains). In the experiments, two different plasma sources were used. First, a surface-wave-sustained Argon plasma torch and second, an underwater diaphragm discharge. For the treatments, nodal segments (10 mm in length) from in vitro cultured plum plants with or without one leaf were prepared. Apical shoots from treated plants (PPV-positive and negative clones as well non-treated controls) were cultivated in vitro for four passages. Then they were rooted and acclimatized to ex vitro conditions, and their virus status was observed periodically for more than 3 years after treatment for the appearance of Sharka symptoms. All plants, acclimatized to ex vitro conditions, were tested for PPV by immune capture–reverse transcription–polymerase chain reaction (IC-RT-PCR). As a first step in understanding the plasma treatment of living plants, a plasma treatment variant causing no damage must be established; this has been done in our previous works. Treatment of plants by plasma with parameters that have been carefully selected leads to better development than the non-treated plants. In the treated in vitro plants, no significant differences were found in the number and length of shoots compared to the control plantlets. In ex vitro acclimated plants, greater stem length was reported, but no differences in leaf number were observed. No significant differences in growth were recorded between the control and plants that were treated twice or three times. At this stage, 3 years after ex vitro cultivation in a greenhouse, Sharka symptoms were not registered on treated in vitro negative PPV plants, and the virus was not detected by IC-RT-PCR. Very mild symptoms were showing in CAP-treated PPV-positive plants. Development of typical Sharka symptoms on non-treated controls were observed. [ABSTRACT FROM AUTHOR]

Cold atmospheric pressure plasma (CAP) has attracted increased interest in recent years for possible biomedical, environmental and agricultural applications. A wide range of cold plasma treatment effects is observed in agricultural applications, like effects on the seed germination and seedling growth, but more systematic investigations are needed. The aim of this study was to identify the most appropriate combinations of the plasma source and duration of treatment positively affecting seed germination. In addition, the effect of cold plasma on the seedling growth and osmotic stress tolerance was studied. The seeds of three Bulgarian durum wheat cultivars were treated with cold plasma in twelve variants. The results obtained were processed statistically via two-way ANOVA. The treatment of seeds with a plasma torch for 20 s and the treatment with underwater diaphragm discharge for 5 min when the seeds were placed in both cameras in two different positions (relative to the electrodes between which the plasma is supplied, "+" and "−") have the greatest positive effect on the all traits related to germination. The analysis of variance reveals that the variation in germination energy, shoot length and root length after the cold plasma treatment of seeds is mainly due to the interaction between the genotype and treatment variant and to a small degree due to the genotype. The treatment of seeds with cold plasma improves the osmoregulation ability of cells and therefore increases the drought resistance of genotypes. [ABSTRACT FROM AUTHOR]

In this paper, an investigation of the interaction of a surface-wave-sustained argon plasma torch with liquids is presented. The plasma is produced by an electromagnetic wave traveling along the plasma–dielectric interface, and at the same time, the plasma is a part of this waveguide structure. Because the interaction of the plasma torch with water (liquid) results in modifications of the properties of both the treated water and the plasma itself, a detailed study of the effects in both media is required. The results of the experimental investigation of a surface-wave-sustained argon plasma torch interaction with liquids show significant changes in the plasma parameters, such as the electron excitation temperature Te and the average rotation temperature Trot. In addition, mechanical waves are produced both in the meniscus surface and in the plasma torch by the interaction between the plasma torch (ionized gas with charged particles and electric field) and the liquid surface, which is different from the effects produced by a neutral gas jet on a liquid surface. As a result of the plasma–water interaction, the water's chemical and physical characteristics, such as the water conductivity, pH, and H2O2 concentration, are modified. As a possible application for water purification, the performed SWD treatment of model wastewater shows a significant variation in nitrate, ammonium, phosphate, and COD (chemical oxygen demand) concentration as a result of the treatment. [ABSTRACT FROM AUTHOR]

This study examined the effectiveness of a 915 MHz atmospheric pressure microwave torch for bulk syngas or hydrogen generation via noncatalytic greenhouse gas (GHG) reforming and its flexibility regarding the amount of soot formed by the process. The investigation shows that plasma-GHG reforming for mass hydrogen generation is feasible without a catalyst at high gas flow rate and microwave power. The best hydrogen production rate and energy yield were 1672 g (H 2)/h and 41.8 g (H 2)/kWh, respectively, at 160 lpm gas flow rate and 40 kW microwave power at a CH 4 /CO 2 ratio of 1. The conversion rates of CH 4 and CO 2 under the same conditions were 95.59% and 95.59%, respectively. The plasma reforming method employed in this study shows its excellent potential for industrial application. [Display omitted] • Greenhouse gases (GHG) reforming for mass hydrogen generation. • Investigated a 915 MHz atmospheric pressure microwave plasma torch for GHG reforming. • Attained hydrogen production rate and energy yield of 1672 g (H 2)/h and 41.8 g (H 2)/kWh. • CH 4 and CO 2 conversion of 95.6% and 95.4%, respectively, were realized. [ABSTRACT FROM AUTHOR]

Inadequate handling of infectious medical waste may promote the spread of the virus through secondary transmission during the transfer process. Microwave plasma, an ease-of-use, device-compact, and pollution-free technology, enables the on-site disposal of medical waste, thereby preventing secondary transmission. We developed atmospheric-pressure air-based microwave plasma torches with lengths exceeding 30 cm to rapidly treat various medical wastes in situ with nonhazardous exhaust gas. The gas compositions and temperatures throughout the medical waste treatment process were monitored by gas analyzers and thermocouples in real time. The main organic elements in medical waste and their residues were analyzed by an organic elemental analyzer. The results showed that (i) the weight reduction ratio of medical waste achieved a maximum value of 94%; (ii) a water–waste ratio of 30% was beneficial for enhancing the microwave plasma treatment effect for medical wastes; and (iii) substantial treatment effectiveness was achievable under a high feeding temperature (≥ 600 °C) and a high gas flow rate (≥ 40 L/min). Based on these results, we built a miniaturized and distributed pilot prototype for microwave plasma torch-based on-site medical waste treatment. This innovation could fill the gap in the field of small-scale medical waste treatment facilities and alleviate the existing issue of handling medical waste on-site. [ABSTRACT FROM AUTHOR]

Hydrogen production via plasma methane pyrolysis is investigated using a microwave plasma torch (MPT) and a gliding arc plasmatron (GAP). The performance of the two plasma sources in terms of methane conversion, product spectrum, and energy efficiency is compared. The physical and chemical properties of the produced carbon particles are compared. The methane conversion is higher in the GAP than in the MPT. In the MPT amorphous spherical carbon particles are produced in the volume of the plasma source. In the GAP methane pyrolysis in the volume stops after the production of acetylene. The conversion of acetylene into solid carbon takes place in a heterogeneous reaction on top of the electrode surfaces instead. This leads to a lower hydrogen selectivity, higher acetylene selectivity and more platelet‐like morphology of the produced carbon particles when compared to the MPT. [ABSTRACT FROM AUTHOR]

Rare earth elements (REEs) have been widely applied in modern industry and material science due to their special chemical properties and luminescence properties, but their environment pollution problem has also attracted attention. How to trace and control impact of REEs on environment and develop highly sensitive methods for REEs analysis have practical significance. Microwave plasma torch (MPT) is a kind of simple, low power consumption (∼200 W) and easily operated plasma generators. When it was coupled with varied mass spectrometers as ion source of mass spectrometry (MS), i.e. MPT-MS can use for the analysis of metal elements in aqueous with the remarkable advantage of only minimal or even no simple pretreatment, and can meet comprehensive requirements of environmental control and water quality monitoring. MPT-MS have also an ability to carry out online real-time monitoring and analysis of water environment. Compared with the traditional ICP-MS, it can obtain more effective information and has higher sensitivity (the detection limit is at sub-ppb level). This paper reviews common methods and research progress of REEs analysis in recent years. Practical applications and advantages of MPT in the analysis of REEs are briefly summarized. Specifically, this paper introduces some work recently done in our group on analysis of REEs by the MPT, including analysis of metal elements distribution in water samples in local Poyang Lake, and general rules of formation and behavior of complex metal ions in the MPT plasma are also proposed afterwards. Through the practically dealing with the Poyang Lake case by the MPT, hopefully this would interest more academia into this area so as to speed up development of the MPT itself.

A sensitive and isotopic interference-free analysis method for Sb was developed based on hydride generation-microwave plasma torch-mass spectrometry (HG-MPT-MS). Compared to the conventional ICP-MS, MPT coupled to an ion trap mass spectrometer enabled much "softer" ionization of Sb under ambient condition, which provided multi-detection modes and various ion forms, such as Sb+, SbO+, SbO 2 −, SbO++H 2 O and so on. These ion formations can be easily regulated by tuning capillary voltage and tube lens voltage, which facilitated elimination of isotopic interference during analysis, for instance the interference of 123Te on 123Sb could be effectively excluded by optimizing parameters of capillary voltage and tube lens voltage. The potential application of HG-MPT-MS for Sb isotope ratio analysis was also demonstrated, which could be determined in different forms, e.g., 123Sb/121Sb or 123Sb16O/121Sb16O. The value of 123Sb/121Sb was determined to be 0.75110 ± 0.00038 (2σ, n > 50). In addition, the detection limit, linearity and spike recovery were also studied. Overall, HG-MPT-MS performed equally well on detection limit (0.05 μg/L) with ICP-MS or HG-AFS. The linearity (R2 = 0.998) was checked in the concentration range of 10–500 μg/L. Spike recovery were evaluated with two soil samples, and the obtained spike recovery ranged 90–100 %. In general, HG-MPT-MS was expected to be a versatile tool for study the biochemical or geochemical behaviors of Sb and other hydride forming elements under ambient condition in a much simpler and more efficient way. [Display omitted] • The method features isotopic interference-free analysis for Sb. • The method enabled sensitive MS analysis of Sb under ambient conditions. • The method provided multi-detection modes and various ion forms for Sb. • HG-MPT-MS was a potential tool for Sb isotope ratio analysis. [ABSTRACT FROM AUTHOR]

Direct, rapid and highly sensitive detection of heavy metals in rice is essential to ensure food safety. In this research, a combination of laser ablation and microwave plasma torch optical emission spectrometry (LA-MPT-OES) was proposed. Based on the optimal observation positions, a high sensitivity and direct determination of Cd, Hg, Pb and Cr in rice were realized. The limits of detection (LOD) were 0.97, 0.12, 0.61 and 0.15 μg / kg , respectively, which were reduced by one order of magnitude compared to the optimal observation height. In addition, the LOD was reduced by one to two orders of magnitude compared with the techniques that require sample pre-treatment. Moreover, the results of the Certified Reference Materials and real samples were in agreement with the reference values with a relative error in the range of 0.28% ∼ 14.16%. The results demonstrated that LA-MPT-OES could be a promising tool to detect heavy metals in rice. • Cd, Hg, Pb and Cr in rice were highly sensitive determined using LA-MPT-OES. • Characterizing the plasma plume of LA-MPT-OES in two dimensions. • The practicality of LA-MPT-OES was validated by quantitative analysis. [ABSTRACT FROM AUTHOR]

A powerful analytical method based on microwave plasma torch/mass spectrometry (MPT-MS) was developed to rapidly detect mental elements in environmental water from Poyang lake in China. With minimum or uncomplicated sample manipulation, raw water samples were ionized by MPT for subsequent LTQ-MS analysis under negative ion mode. Typical potential contamination sources such (e.g., iron, cobalt, and nickel) were detected and identified by collision-induced dissociated (CID) experiment. It was found that the three metallic elements were formed as [M(NOx)mOn]−, which was universal; thus, they could be target ions. For the given elements, their limits of detection (LOD) were assessed as 0.09 μg•L−1 for iron ion, 0.03 μg•L−1 for cobalt ion, and 0.33 μg.L−1 for nickel ion under the optimized conditions; good determination coefficient (R2 ≥ 0.99) and the relative standard deviation (RSD, 2.0–11%, n = 11) were obtained. For current actual samples under testing, short analysis time for a single sample (less than 1 min), the average levels for iron, cobalt, and nickel, reached allowable concentrations of national standards, which also suggested this method is practically effective and usable. Moreover, possible ionization mechanism of metallic elements in MPT source was also discussed in this work, which may provide insight and useful information for the metal organics derived from water environment or metabonomics by MPT-MS. On the whole, this study lays a solid basis for the in-site mass spectrometry analysis of aqueous samples in relevant fields.

Feature Application: A cold microwave plasma torch operating at low wave power at atmospheric pressure can be successfully used for treatment of biological systems in medicine and agriculture without thermal damage and any unwanted and unacceptable effects of the microwave radiation but with high bactericidal, virucidal and fungicidal effects without the use of harmful chemicals. Cold atmospheric plasma (CAP) applications in various fields, such as biology, medicine and agriculture, have significantly grown during recent years. Many new types of plasma sources operating at atmospheric pressure in open air were developed. In order to use such plasmas for the treatment of biological systems, plasma properties should fulfil strong requirements. One of the most important is the prevention from heating damage. That is why in many cases, the post-discharge region is used for treatment, but the short living particles in the active discharge zone and reactions with them are missed in that case. We use the active region of surface-wave-sustained argon plasma for biological systems treatment. The previous investigations showed good bactericidal, virucidal, seeds germination and decontamination effects at a short treatment time, but the discharge conditions for bio-medical applications need specific adjustment. A detailed theoretical and experimental investigation of the plasma characteristics and their possible optimization in order to meet the requirements for bio-medical applications are presented in this paper. The length of the plasma torch, the temperature at the treatment sample position and the microwave radiation there are estimated and optimized by the appropriate choice of discharge tube size, argon flow rate and microwave power. [ABSTRACT FROM AUTHOR]

The raw sample was merely filtered to wiping off the suspended, and then partly (10 mL) translated into amber glass vials. Furthermore, add a small quantity of HNO 3 in order to make the solution reach the optimal acidity level of 0.03 moL.L−1 for the coming MPT-MS measurements. A powerful analytical method based on microwave plasma torch/mass spectrometry (MPT-MS) was developed to rapidly detect mental elements in environmental water from Poyang lake in China. With minimum or uncomplicated sample manipulation, raw water samples were ionized by MPT for subsequent LTQ-MS analysis under negative ion mode. Typical potential contamination sources such (e.g., iron, cobalt, and nickel) were detected and identified by collision-induced dissociated (CID) experiment. It was found that the three metallic elements were formed as [M(NO x) m O n −, which was universal; thus, they could be target ions. For the given elements, their limits of detection (LOD) were assessed as 0.09 μg•L−1 for iron ion, 0.03 μg•L−1 for cobalt ion, and 0.33 μg.L−1 for nickel ion under the optimized conditions; good determination coefficient (R2 ≥ 0.99) and the relative standard deviation (RSD , 2.0–11%, n = 11) were obtained. For current actual samples under testing, short analysis time for a single sample (less than 1 min), the average levels for iron, cobalt, and nickel, reached allowable concentrations of national standards, which also suggested this method is practically effective and usable. Moreover, possible ionization mechanism of metallic elements in MPT source was also discussed in this work, which may provide insight and useful information for the metal organics derived from water environment or metabonomics by MPT-MS. On the whole, this study lays a solid basis for the in-site mass spectrometry analysis of aqueous samples in relevant fields. [ABSTRACT FROM AUTHOR]

Cold atmospheric plasma (CAP) applications in various fields, such as biology, medicine and agriculture, have significantly grown during recent years. Many new types of plasma sources operating at atmospheric pressure in open air were developed. In order to use such plasmas for the treatment of biological systems, plasma properties should fulfil strong requirements. One of the most important is the prevention from heating damage. That is why in many cases, the post-discharge region is used for treatment, but the short living particles in the active discharge zone and reactions with them are missed in that case. We use the active region of surface-wave-sustained argon plasma for biological systems treatment. The previous investigations showed good bactericidal, virucidal, seeds germination and decontamination effects at a short treatment time, but the discharge conditions for bio-medical applications need specific adjustment. A detailed theoretical and experimental investigation of the plasma characteristics and their possible optimization in order to meet the requirements for bio-medical applications are presented in this paper. The length of the plasma torch, the temperature at the treatment sample position and the microwave radiation there are estimated and optimized by the appropriate choice of discharge tube size, argon flow rate and microwave power.

An atmospheric pressure plasma-enhanced chemical vapor deposition process using a microwave plasma torch has been used for titania thin film synthesis. A dynamic deposition mode was set up to cover a square centimeter surface with a nanostructured TiO 2 film. The process parameters were studied and optimized to control the coating crystallinity and morphology and limit the formation of powder in the plasma phase. Contrary to static deposition, the substrate movement promotes a film growth by particles agglomeration in the reference conditions, leading to a cauliflower-like morphology. Then, the precursor proportion in the plasma appears to be determinant in the TiO 2 film microstructure. For a precursor flow rate beyond 0.2 slpm, the titania nanoparticles formation in the gas phase is promoted and the thin film is growing by particles agglomeration, leading to a columnar cauliflower-like morphology. At a flow rate of 0.2 slpm, the growth by surface reaction is promoted and the TiO 2 film is columnar, where each column is an anatase crystal. After the optimization of the substrate holder movement, it was possible to deposit this last microstructure homogeneously on a square centimeter surface. • The substrate movement modifies the thin film growth mechanism. • The precursor flow rate is determinant to control the film growth mechanism. • A columnar film composed of aligned titania crystals is obtained on a large surface. [ABSTRACT FROM AUTHOR]

With the widespread application of rare earth elements analysis, the development of rapid detection technology of rare earth elements has increasingly become a necessity within the industry. Microwave Plasma Torch (MPT) as the ion source and Quadrupole Mass Spectrometry (QMS) as the mass analyzer to develop a method for fast detection of rare earth elements (REEs) in water and ore samples has been developed and discussed in this paper. With the MPT-QMS method, for elements Y, La, Ce, Nd, Eu in water samples, the limits of detection (LODs) are 11.0-60.5 μg/L, and the linear ranges are 50-1000 μg/L. When analyzing ore samples, the samples were firstly digested by acid solution and the sample solution formed an aerosol, which was then cooled to keep it dry. The aerosol entered the plasma by the centre tube of the MPT and formed REE ions. These ions enter the QMS, and concentrations of REE elements can be quantitatively determined. Repeated analyses of the same sample by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) yield similar results, indicating that the semi-quantitative analyses of MPT-QMS are precise and reliable. Therefore, MPT coupled with QMS is suitable for portable, rapid analysis of metal elements in water and can be used in the field of in situ quality monitoring of environmental and drinking water.

An atmospheric pressure microwave plasma torch operating at 2.45 GHz frequency using a surfaguide waveguide fed by argon gas at a constant rate is characterized at various microwave power settings. Coarse optical emission spectroscopy technique is used to diagnose the plasma parameters. The Boltzmann plot method is implemented to measure the electron temperature. Using the Doppler shift of the strong argon atomic spectral lines, the plasma velocity is determined. These results are in good agreement with earlier studies conducted on similar microwave plasma torches at a lower power setting. In this study, we exceed the previous power limitations observed in earlier studies and scan the microwave power in increments up to 2 kW. [ABSTRACT FROM AUTHOR]

The distinction between natural stones such as marble and granite, and artificial stones formed mostly by unsaturated polyester resin with the addition of disintegrating slag of natural stone and some additives is difficult to determine accurately and quickly by chemical composition. Consequently, the development of Infrared Reflection Spectroscopy (IRS) has been established for for this purpose, but has limitations due to the high purity requirement of samples. Based on the high ability of thermal desorption and ionization of Microwave Plasma Torch (MPT), analyte could be ionized in a short time. In this study, Microwave Plasma Torch Mass Spectrometry (MPT-MS) was used to directly analyze natural and artificial stone without sample pretreatment. The fingerprint mass spectra of these stones were obtained in the mass range of m/z 50-1000. All data from artificial stones and natural stones were analyzed by principal component analysis (PCA) for differentiation of artificial and natural stones. The results show that abundant fingerprints of stones were acquired by MPT-MS. With the application of PCA, natural stones were successfully and rapidly differentiated from artificial stones. CO2 and H2O molecular clusters were desorbed from natural stones, however, organics (i.e. adhesives) were desorbed from artificial stone. Herein, MPT-MS is a new mass spectrometry technology under atmospheric pressure. Without the assistance of spray, laser, matrix and heat, the stones can be analyzed by MPT-MS directly. The method has high analytical speed (1 min per sample), high sensitivity, and does not require sample pretreatment. The results indicate that direct MPT-MS analysis allows rapid differentiation of untreated solid materials, such as construction stones, at the molecular level.

Rapid qualitative and quantitative analysis of solid samples (e.g., pharmaceutical preparations) by using a small and low-resolution mass spectrometer without MS/MS function is still a challenge in ambient pressure ionization mass spectrometric analysis. Herein, a practically efficient method termed microwave-enhanced in-source decay (MEISD) using microwave plasma torch desorption ionization coupled with time-of-flight mass spectrometry (MPTDI-TOF MS) was developed for fast analysis of pharmaceutical tablets using a miniature TOF mass spectrometer without tandem mass function. The intensity of ISD fragmentation was evaluated under different microwave power values. Several factors, including desorption distance and time that might affect the signal intensity and fragmentation, were systematically investigated. It was observed that both the protonated molecular ions and major fragment ions from the active ingredients in tablets could be found in the full-scan mass spectra in positive ion mode, which were comparable to those obtained by a commercial LTQ-XL ion trap mass spectrometer. The structures of the ingredients could be elucidated in detail using the MEISD method, which promotes our understanding of the desorption/ionization processes in microwave plasma torch (MPT). Quantitative analysis of 10 tablets was achieved by full-scan MPTDI-TOF MS with low limit of detection (LOD, 0.763 mg/g), acceptable relative standard deviation (RSD < 7.33%, n =10), and 10 s for each tablet, showing promising applications in high throughput screening of counterfeit drugs. [ABSTRACT FROM AUTHOR]

It is of sustainable interest to improve the sensitivity and selectivity of the ionization process, especially for direct analysis of complex samples without matrix separation. Herein, four ambient ionization methods including desorption atmospheric pressure chemical ionization (DAPCI), heat-assisted desorption atmospheric pressure chemical ionization (heat-assisted DAPCI),microwave plasma torch (MPT) and internal extractive electrospray ionization (iEESI) were employed for comparative analysis of the navel orange tissue samples by mass spectrometry. The volatile organic compounds (e.g. ethanol, vanillin, leaf alcohol and jasmine lactone) were successfully detected by non-heat-assisted DAPCI-MS, while semi-volatile organic compounds (e.g. 1-nonanol and ethyl nonanoate) together with low abundance of non-volatile organic compounds (e.g. sinensetin and nobiletin) were obtained by heat-assisted DAPCI-MS. Typical nonvolatile organic compounds [e.g. 5-(hydroxymethyl)furfural and glucosan] were sensitively detected with MPT-MS. Compounds of high polarity (e.g. amino acids, alkaloids and sugars) were easily profiled with iEESI-MS. Our data showed that more analytes could be detected when more energy was delivered for the desorption ionization purpose; however, heat-sensitive analytes would not be detected once the energy input exceeded the dissociation barriers of the analytes. For the later cases, soft ionizationmethods such as iEESIwere recommended to sensitively profile the bioanalytes of high polarity. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

An original low-temperature atmospheric pressure plasma-enhanced chemical vapor deposition process was used to deposit titanium dioxide thin films. The parametric study in dynamic mode deposition aimed at growing an ideal columnar film composed of aligned anatase monocrystals as solar cell photoanode, previously obtained on silicon wafers in static mode deposition. A process parameters optimization was necessary to deposit onto thermally sensitive glass/FTO substrates. In this paper, the morphology, crystallinity and optical transmission of the coatings have been studied. The coatings display a columnar cauliflower-like structure, composed of TiO2 amorphous particles assembly. After deposition, the light transmission properties of the substrate were reduced. As a solution, an ultrasound bath cleaning was set up to enhance the transmitted light through the photoanode.

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Microwave plasma torch (MPT) is a simple and low power-consumption ambient ion source. And the MPT Mass spectra of many metal elements usually exhibit some novel features different from their inductively coupled plasma (ICP) mass spectra, which may be helpful formetal element analysis. Here, we presented the results about the MPTmass spectra of copper andmolybdenum elements by a linear ion trap mass spectrometer (LTQ). The generated copper ormolybdenumcontained ions in plasmawere characterized further in collision-induced dissociated (CID) experiments. These researches built a novel, direct and sensitive method for the direct analysis of trace levels of copper and molybdenum in aqueous liquids. Quantitative results showed that the limit of detection (LOD) by using MS² procedure was estimated to be 0.265 μg/l (ppb) for copper and 0.497 μg/l for molybdenum. The linear dynamics ranges cover at least 2 orders of magnitude and the analysis of a single aqueous sample can be completed in 5-6min with a reasonable semi-quantitative sense. Two practical aqueous samples, milk and urine, were also analyzed qualitativelywith reasonable recovery rates and RSD. These experimental data demonstrated that the MPTMS is able to turn into a promising and hopeful tool in field analysis of copper and molybdenumions in water and some aqueous media, and can be applied in many fields, such as environmental controlling, hydrogeology, and water quality inspection. Moreover, MPT MS could also be used as the supplement of ICP-MS for the rapid and in-situ analysis of metal ions. [ABSTRACT FROM AUTHOR]

Microwave plasma torch (MPT) is a simple and low power-consumption ambient ion source. When MPT mass spectrometry is applied in the detection of some metal elements, the metallic ions exhibit some novel features which are different from traditional ICP mass spectrometry and may be helpful for the metal element analysis. Zinc and cadmium both are important transition metals with wide applications in modern industry. Here, we presented the research results of the MPT mass spectra of zinc and cadmium elements by a linear ion trap mass spectrometer (LTQ) both in positive and negative modes. Without any sample pretreatment, the aqueous samples were pneumatically nebulized and the aerosols were generated. The dried aerosols were introduced into the plasma through the central tube of the MPT to generate the complex metallic ions. For the positive composite ions of zinc and cadmium, the general forms are the hybrid of M(NO 3 )· n OH· m H 2 O, thus the MPT mass spectra are extremely complicated and unsuitable for the quantitative monitoring. However, the MPT negative ionic of zinc and cadmium is quite regular in the forms of M(NO 3 ). We also showed that the limit of detection (LOD) for zinc and cadmium in negative mode can be achieved at the level of 10 μg/L (ppb). Therefore, the negative mode MPT mass spectrometry can be used as one of the alternative supplements of ICP-MS applied in on-line monitoring of zinc and cadmium metal ions in water at trace levels, which will be promising in the field analysis of metal elements and the rapid water quality inspection. [ABSTRACT FROM AUTHOR]

Rare earth elements (REEs) have been widely applied in modern industry and material science due to their special chemical properties and luminescence properties, but their environment pollution problem has also attracted attention. How to trace and control impact of REEs on environment and develop highly sensitive methods for REEs analysis have practical significance. Microwave plasma torch (MPT) is a kind of simple, low power consumption (∼200 W) and easily operated plasma generators. When it was coupled with varied mass spectrometers as ion source of mass spectrometry (MS), i.e. MPT-MS can use for the analysis of metal elements in aqueous with the remarkable advantage of only minimal or even no simple pretreatment, and can meet comprehensive requirements of environmental control and water quality monitoring. MPT-MS have also an ability to carry out online real-time monitoring and analysis of water environment. Compared with the traditional ICP-MS, it can obtain more effective information and has higher sensitivity (the detection limit is at sub-ppb level). This paper reviews common methods and research progress of REEs analysis in recent years. Practical applications and advantages of MPT in the analysis of REEs are briefly summarized. Specifically, this paper introduces some work recently done in our group on analysis of REEs by the MPT, including analysis of metal elements distribution in water samples in local Poyang Lake, and general rules of formation and behavior of complex metal ions in the MPT plasma are also proposed afterwards. Through the practically dealing with the Poyang Lake case by the MPT, hopefully this would interest more academia into this area so as to speed up development of the MPT itself. [ABSTRACT FROM AUTHOR]

In this study, a microwave plasma torch working at atmospheric pressure has been used for TiO 2 thin film synthesis. We first optimised the deposition conditions in order to avoid the formation of powder in the plasma phase. Then, the characterisation of the TiO 2 films deposited in the optimised conditions revealed that both morphology and phase structure of the film are radial dependent. At the centre, the film is crystallised, exhibiting a well-defined columnar microstructure. Meanwhile, at the periphery, the film is amorphous, with a cauliflower-like structure. [ABSTRACT FROM AUTHOR]

Abatement of fluorinated compounds (FCs) used in semiconductor and display industries has received an attention due to the increasingly stricter regulation on their emission. We have developed a 2.45 GHz microwave plasma torch with reverse vortex reactor (RVR). In order to design a reverse vortex plasma reactor, we calculated a volume fraction and temperature distribution of discharge gas and waste gas in RVR by ANSYS CFX of computational fluid dynamics (CFD) simulation code. Abatement experiments have been performed with respect to SF 6 , NF 3 by varying plasma power and N 2 flow rates, and FCs concentration. Detailed experiments were conducted on the abatement of NF 3 and SF 6 in terms of destruction and removal efficiency (DRE) using Fourier transform infrared (FTIR). The DRE of 99.9% for NF 3 was achieved without an additive gas at the N 2 flow rate of 150 liter per minute (L/min) by applying a microwave power of 6 kW with RVR. Also, a DRE of SF 6 was 99.99% at the N 2 flow rate of 60 L/min using an applied microwave power of 6 kW. The performance of reverse vortex reactor increased about 43% of NF 3 and 29% of SF 6 abatements results definition by decomposition energy per liter more than conventional vortex reactor. [ABSTRACT FROM AUTHOR]

The pressure sensor application gained recently substantial interest in many fields of basic and applied research and applications. In this paper, microelectromechanical system (MEMS)-based pressure sensor contains nanostructured electrode consisting of carbon nanotube (CNT) array. CNTs are directly grown on such electrode by plasma-enhanced chemical vapor deposition method using microwave plasma torch at atmospheric pressure. This growth method enables us to use a simple electrode structure without need of buffer layer and time-consuming lithography process. Combination of CNTs field emission and MEMS membrane mechanical properties make possible to enhance sensitivity of the sensor. Field emission properties of CNTs are measured by newly developed system enabling us precise measurement of expecting properties, such as dependence on diaphragm (upper electrode) distance, applied voltage, and stability of the sensor. Measured values are compared with a numerical modeling of the membrane system in CoventorWare software by finite-element method. We also suggest encapsulating the sensor using glass frit bonding because such method is more suitable for high vacuum requirements of the field emission operation. [ABSTRACT FROM PUBLISHER]

Pyrolysis fuel oil (PFO) processing by microwave plasma torch was developed for the production of hydrogen. The PFO cracking process was performed at atmospheric pressure in the absence of catalyst and effect of plasma gas on the production rate of hydrogen and light hydrocarbons (C 2 –C 4 ) was evaluated. In the first step, effect of the applied power and the working gas flow rate was investigated. In the second step, the applied power and working gas rate were set to 650 W and 4000 sccm, respectively, which were provided by combining methane or ethane as 0%, 2.5%, 7.5%, and 20% with argon. By increasing the percentage of the existing methane in argon, production rate of the sum of the light hydrocarbons was increased and that of hydrogen was reduced, but it was more than the case when argon was applied alone. By increasing ethane percentage, hydrogen production and light hydrocarbon rate were increased. The best conditions of the plasma gas for producing hydrogen at the power of 650 W were obtained as 5CC PFO feed, 2500 sccm (80%) argon, and 500 sccm (20%). The hydrogen production rate in optimized conditions was 2343.16SCCM with selectivity of 84.41%. Sum of the obtained hydrocarbons in this test was 434.25 sccm. Another parameter in the present study was the feed volume processed by plasma. In this case, 5 cc, 3 cc, and 1 cc of the feed were tested when the plasma gas was 3000 sccm argon with the power of 650 W. The results showed that, by increasing the feed, the products were increased. In the processing of 5 cc feed with plasma, 896.41 sccm hydrogen and 61 sccm light hydrocarbon were produced. [ABSTRACT FROM AUTHOR]

Highlights: [•] Pyrolysis Fuel Oil (PFO) was processed by Microwave plasma torch. [•] The power and flow rate of carrier gases on the cracking operation were studied. [•] The increase of the power results in more products. [•] The production rate of products increase with increasing the flow rate. [ABSTRACT FROM AUTHOR]

Ambient ionization is the new revolution in mass spectrometry (MS). A microwave plasma produced by a microwave plasma torch (MPT) at atmospheric pressure was directly used for ambient mass spectrometric analysis. H3O+ and NH4+ and their water clusters from the background are formed and create protonated molecules and ammoniated molecules of the analytes. In the full-scan mass spectra, both the quasi-molecular ions of the analytes and their characteristic ionic fragments are obtained and provide evidence of the analyte. The successful detection of active compounds in both medicine and garlic proves that MPT has the efficient desorption/ionization capability to analyze solid samples. The obtained decay curve of nicotine in exhaled breath indicates that MPT-MS is a useful tool for monitoring gas samples in real time. These results showed that the MPT, with the advantages of stable plasma, minimal optimization, easy, solvent-free operation, and no pretreatment, is another potential technique for ambient MS. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]