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Pyrolysis experiment of simulated exogenous complex organics synthesized from the gas mixtures of CO, NH3, and H2O by 3 MeV proton irradiation.

High molecular weight organic matter synthesized from mixtures of carbon monoxide, ammonia and water gases similar to those found in the interstellar medium were irradiated with a 3 MeV proton beam and analyzed by Curie point pyrolysis with detection by gas chromatograph and mass spectrometer (Pyr-GC-MS). A wide variety of organic compounds, not only a number of amide compounds, but also heterocyclic and polycyclic aromatic hydrocarbons (PAHs), were detected among the products of the pyrolysis. The present data shows that primary and primitive organic matter serving as precursors to bioorganic compounds such as amino acids, nucleic acid bases and sugar might have been formed in a gaseous mixture of similar composition to that of the interstellar dust environment.

Amides↗

Experience and lessons learned from sewage sludge pyrolysis in Australia.

Management of sewage sludge via "publicly acceptable" methods is becoming increasingly difficult, primarily due to health and environmental concerns with respect to reuse of the product in agriculture. Consequently thermal processes are gaining popularity with significantly increased interest being shown in pyrolysis and gasification processes, due to their "non-incineration status". One such process is the ENERSLUDGE technology which has been developed and commercialised by Environmental Solutions International Ltd (ESI). The world's first commercial ENERSLUDGE plant is located at the Subiaco Wastewater Treatment Plant (WWTP) that was handed over to the client, the Water Corporation of Western Australia in June 2001. Extensive design knowledge and operational experience has now been accumulated from this commercial pyrolysis facility and future applications of the technology will benefit immensely from the lessons learned and experience gained from this facility.

Agriculture↗

Effect of pyrolysis temperature and hold time on the characteristic parameters of adsorbent derived from sewage sludge.

According to the Doehlert's matrix method, the adsorbent derived from sewage sludge was prepared through chemical activation under controlling the pyrolysis temperature and hold time. The characteristic parameters including the total yield, adsorption of methylene blue, adsorption of iodine, BET surface area, micro-pore volume are 35%--49%, 16.5--38 mg/g, 285--362 mg/g, 185--359 m2/g, and 0.112--0.224 m3/g, respectively. According to the experimental data, the multi-linear regression method was adopted to fit the relations between the characteristic parameters and influential factors. At final, through optimization method, the optimal adsorbent is obtained when using 62 min as hold time and 1105K as pyrolysis temperature. Under the conditions, the adsorbent was produced and compared the characteristic parameters with model forecast value, the coherence is satisfied.

Adsorption↗

[The effect of alkalinity of methylation reagent on isomerization and degradation of polyunsaturated fatty acids with pyrolysis gas chromatography].

Simultaneous pyrolysis and methylation gas chromatography (SPM-GC) is a fast analytical method which was developed in recent years. However, the strong alkalinity of tetramethylammonium hydroxide (TMAH) may result in the isomerization and degradation of polyunsaturated fatty acids in oils and fats during analysis. This paper describes the application of SPM-GC to polyunsaturated fatty acids in soybean oil and the isomerization and degradation may be prevented by choosing the optimum proportion of TMAH to methanol which is 1:50 (pH 8.8). With this chosen optimum proportion there were no detectable isomerized and degraded peaks in the chromatograms. Pyrograms were obtained by interfacing a Curie-point pyrolyser to a Shimadzu GC-14A gas chromatograph equipped with a flame ionisation detector. A capillary column (FFAP) was used. All of the pyrolysis products were identified by mass spectrometry which was carried out with a Varian 3400 gas chromatograph interfaced to a Finnigan SSQ 710 mass spectrometer using electron impact ionisation (70 eV). This method is simpler and more convenient than both the methods "neutralization of acid" and "simultaneous injection of the sample and a short chain fatty acid methylester" reported in the previous papers.

Chromatography, Gas↗

[Degradation of phenols formed during lignin pyrolysis by microfungi of genera Trichoderma and Penicillium].

This work presents the data on the rate of utilization of phenols formed during lignin pyrolysis by micromycetes of the genera Trichoderma and Penicillium. Trichoderma strains utilized phenols at the concentration of liquid pyrolytic products of 0.5-1%, while representatives of Penicillium degraded over 50% phenols at the concentration of pyrolytic products of 2%. Micromycete cultures completely utilized phenol and the cresol-xylenol fraction. Penicillium strains demonstrated a more active growth on media containing phenol, pcresol, or guaiacolic acid as the source of carbon as compared to Trichoderma. m-Cresol and m-xylenol in micromycete growth media containing products of lignin pyrolysis seem to be utilized by co-oxidation.

Biodegradation, Environmental↗

[Identification of 10 kinds of Zanthoxylum by pyrolysis GC].

In this paper, pyrolysis GC was applied to differentiate and fingerprint 10 kinds of Zanthoxylum on an OV-101 capillary column. Analytical conditions with this column, operating temperature, pyrolysis time and peak identifications are discussed.

Chromatography, Gas↗

Abuse of smoking methamphetamine mixed with tobacco: I. Inhalation efficiency and pyrolysis products of methamphetamine.

Experiments of smoking methamphetamine in tobacco have been investigated. Inhalation efficiencies of methamphetamine into tar were 6 to 17% according to the additive amounts, suction volume, and intervals of smoking. Major pyrolysis products of methamphetamine in tar were identified as methamphetamine, amphetamine, phenylacetone, dimethylamphetamine, N-formyl-, N-acetyl-, N-propionyl-, and N-cyanomethyl-methamphetamine by the spectral analysis of infrared spectra (IR), mass spectra (MS), and proton magnetic resonance spectra (PMR), and comparison with the samples synthesized from authentic samples by one step. The largest pyrolysis product was N-cyanomethylmethamphetamine which is a new compound and easily metabolized to methamphetamine in the body. Methamphetamine itself transferred into tar was not so large, but the total active compounds in tar which would be metabolized to methamphetamine in the body were considerably larger.

Administration, Inhalation↗

Pyrolysis analysis of the herbicide paraquat on cannabis by coupled gas chromatography-infrared spectroscopy.

Pyrolysis gas chromatography coupled with infrared identification of eluted peaks confirms that paraquat is pyrolyzed into chloromethane and 4,4'-dipyridyl at smoking temperatures and above. This reaction occurs at 610 degrees C to completion in small amounts in an inert atmosphere. The toxicity of 4,4'-dipyridyl remains to be determined. Pyrolysis of contaminated marijuana also produces the same two products, although detection at low limits is difficult with this procedure.

2,2'-Dipyridyl↗

Acute toxicosis of budgerigars (Melopsittacus undulatus) caused by pyrolysis products from heated polytetrafluoroethylene: clinical study.

Polytetrafluoroethylene (PTFE), a synthetic polymer widely used as a nonstick surface in cookware, releases toxic pyrolysis products when exposed to excessive heat. Thirty-two budgerigars (Melopsittacus undulatus) were exposed to pyrolysis products of either heated PTFE cookware or plain aluminum cookware in a specially designed exposure chamber for given periods. Clinical signs were recorded and necropsies were done on all birds at the termination of each exposure period. The PTFE products caused acute respiratory distress and rapid death in many of the exposed birds. At necropsy, lesions were seen only in the respiratory tract--extensive pulmonary hemorrhage and congestion.

Acute Disease↗

[Differentiation of structural viral proteins using pyrolysis gas chromatography].

Types 1, 2, and 5 of structural proteins of adenovirus as well as human albumin, pepsin, trypsin, and ribonuclease tend to exhibit characteristic substance patterns when exposed to pyrolysis-gas chromatography. Those patterns may be helpful in differentiating between those proteins. The presence of a distributional pattern is assumed to depend, in most cases, not only on the given amino acid composition, but also on the amino acid sequence of the protein proper. Samples of complex composition, such as complete viruses or allantois fluids, were much less suitable for differentiation by means of pyrolysis-gas chromatography.

Adenoviridae↗

Ultrastructural alterations of rat lung exposed to pyrolysis products of polytetrafluoroethylene (PTFE, Teflon).

Ultrastructural changes of the lung tissues were evaluated in rats exposed to the pyrolysis products of Teflon at 380 degrees C., 400 degrees C;, and 450 degrees C., respectively, for 4 hours. At 450 degrees C. Teflon evolved numerous tiny particles (0.02 to 0.04 mum.), which were considered to be the toxic material, and at 550 degrees C., in addition to the tiny particles, large spherical particles (0.7 to 5.0 mum) were found. No particles were observed in the pyrolysis product produced at temperatures between 380 degrees C. and 425 degrees C. There were no clinical symptoms or lung alterations induced at temperatures below 425 degrees C colloidal carbon injected as a marker of increased vascular permeability did not pass through the alveolar capillary endothelium. At 450 degrees C. (approximate lethal temperature) rats revealed severe respiratory difficulty, pulmonary edema, hemorrhage, and necrosis of the tracheobronchial epithelium. The membranous pneumocytes appear to be vulnerable to the Teflon fume causing cytoplasmic swelling, bleb formation, fragmentation, and denudation. Similar changes were found in the endothelial cells, but to a much lesser extent. When Teflon fume generated at 450 degrees CnWAS FILTERED THROUGH A Millipore filter (pore size 0.2 mum.), rats revealed only slight degenerative changes in the superficial tracheobronchial epithelium, but no clinical signs.

Animals↗

Enhanced Performance in All-Inorganic AgBiS2 Photodetectors via Oxygen-Inhibited Spray Pyrolysis Deposition.

AgBiS2 has emerged as a promising optoelectronic material due to its broad spectral response and strong light absorption. However, the current use of high-boiling solvents and organic buffers restricts fundamental studies and further performance optimization of AgBiS2's intrinsic properties. In this study, we develop an organic buffer-free AgBiS2 photodetector prepared using a low-temperature ultrasonic spray pyrolysis technique. Our theoretical analysis revealed that oxygen doping alters the optoelectronic characteristics by enhancing the density of states near the Fermi level, leading to consequent severe nonradiative charge carrier recombination. By incorporating excess thiourea while maintaining optimal substrate temperature for enhanced crystallinity, we successfully suppress oxygen defects and consequently improve photodetection performance. The optimized device exhibits a high responsivity of 0.046 A W-1 at 1050 nm, a low noise level (<8.5 &#xd7; 10-19 A2 Hz-1), and a fast response time (0.07 &#x3bc;s rise, 0.60 &#x3bc;s decay). Benefiting from the rapid response, the photodetector delivers high-resolution imaging with sharp edge definition. This work eliminates the interference of organic buffer layers to directly reveal how oxygen defect modulation affects the intrinsic optoelectronic properties of AgBiS2, offering a scalable pathway for high-performance, solution-processed photodetectors.

near-infrared detector↗

Differentiation of brewing yeast strains by pyrolysis mass spectrometry and Fourier transform infrared spectroscopy.

Two rapid spectroscopic approaches for whole-organism fingerprinting--pyrolysis mass spectrometry (PyMS) and Fourier transform infrared spectroscopy (FT-IR)--were used to analyse 22 production brewery Saccharomyces cerevisiae strains. Multivariate discriminant analysis of the spectral data was then performed to observe relationships between the 22 isolates. Upon visual inspection of the cluster analyses, similar differentiation of the strains was observed for both approaches. Moreover, these phenetic classifications were found to be very similar to those previously obtained using genotypic studies of the same brewing yeasts. Both spectroscopic techniques are rapid (typically 2 min for PyMS and 10 s for FT-IR) and were shown to be capable of the successful discrimination of both ale and lager yeasts. We believe that these whole-organism fingerprinting methods could find application in brewery quality control laboratories.

Beer↗

Characterization of the thermal decomposition and polymerization of arprocarb using pyrolysis-GC-MS.

Arprocarb is a carbamate type insecticide used to control cockroaches, flies, mosquitoes, and is a lawn and turf insect growth regulator. In order to evaluate the effects of the thermal behavior of arprocarb on its bioactivity or the environment, its thermal decomposition and polymerization were characterized using pyrolysis-GC-MS (Py-GC-MS). Arprocarb was pyrolysed at 450 degrees C, 600 degrees C, 750 degrees C, and 900 degrees C, respectively. In all 71 components were determined. It was found that arprocarb was obviously decomposed when the temperature was lower (450 approximately 750 degrees qC), and a large number of mono- and polycyclic aromatic hydrocarbons (PAHs) were produced at higher temperatures (750 approximately 900 degrees C). Furthermore, the variety of the representative compounds versus the temperature was reported. The research results can provide useful information for the understanding of the thermal behavior of arprocarb.

Carbamates↗

The identification of ibuprofen and analogues in urine by pyrolysis gas chromatography mass spectrometry.

The pyrolysis gas chromatography mass spectrometry of Ibuprofen, Fenoprofen, Naproxen and Ketoprofen, a series of anti-inflammatory propionic acid derivatives, is shown to proceed via decarboxylation and elimination to yield characteristic ethyl and vinyl fragments. The pyrogram enables the identification of the drug to be achieved as the pure compound, in a formulated dosage form or excreted in urine. The presence of metabolites derived from Ibuprofen causes four new fragments to be observed in the urine pyrogram. The identification of 16 components of the control urine pyrogram is presented.

Anti-Inflammatory Agents↗

Analysis of drugs by pyrolysis. II--An improved method for the determination of carpronium chloride in plasma by selected ion monitoring.

A sensitive and specific method has been devised for the determination of carpronium chloride, a parasympathomimetic agent, in plasma. The method is based on selected ion monitoring combined with the pyrolysis reaction of (3-isopropoxycarbopropyl)trimethylammonium chloride derived by transesterification of the drug. Carpronium chloride-[2H9] is used as an internal standard. The drug and the internal standard are separated from deproteinized plasma by ion pair extraction, and converted into isopropyl ester derivatives. The derivatives are pyrolysed to produce the respective isopropyl N,N-dimethyl-gamma-aminobutyrates available for selected ion monitoring. Measurement is carried out in the electron impact mode by monitoring the fragment ion [M-OC3H7]+ (m/z 114, 120). The method is applicable to 5 ng ml-1 plasma with about 10% coefficient of variation, and has been utilized successfully for the pharmacokinetics of carpronium chloride in man.

Animals↗

Identification and quantification of arsenocholine and acetylarsenocholine in trace amounts in biological material by use of pyrolysis gas chromatography/mass spectrometry.

An analytical method, based on a selective extraction and pyrolysis gas chromatography/mass spectrometry assay of arsenocholine and acetylarsenocholine in aquatic organisms, is described. Characteristic fragmentation patterns were obtained from pyrolytically demethylated compounds. The molecules were rearranged in unique pathways which differed from those of corresponding nitrogen analogues. Qualitative determination of arsenocholine and acetylarsenocholine was achieved by gas chromatographic as well as mass spectrometric analysis of the thermal degradation products (trimethylarsine, dimethylvinylarsine and the demethylated arsenocholine or acetylarsenocholine). Arsenocholine and acetylarsenocholine in fish from industrially polluted water were isolated and identified. Massfragmentographic quantification of the arsenic compounds in fish was carried out by use of deuterium labelled analogues of arsenocholine and acetylarsenocholine as internal standards. The method showed a high sensitivity.

Animals↗