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PubMed2001

Pyrolysis mass spectrometry (PyMS) and 16S-23S rDNA spacer region fingerprinting suggests the presence of novel acinetobacters in activated sludge.

Screening of large numbers of Acinetobacter spp. from activated sludge systems with Pyrolysis Mass Spectrometry (PyMS) showed that many did not cluster tightly with the currently described genomic species which have been obtained mainly from clinical sources. Selected isolates were then genotypically fingerprinted using their 16S-23S rDNA spacer region, and again the data revealed considerable differences in the genomic fingerprints of many of these activated sludge isolates to the predominantly clinical genomic species. In fact, few could be identified from them. The possibility that the current speciation within this genus is not adequate to encompass all these environmental isolates is addressed in relation to the methods used to study the population dynamics of Acinetobacter in activated sludge.

Acinetobacter↗

PubMed1975

Classification of some Gymnoascaceae by pyrolysis-gas-liquid chromatography using added marker compounds.

Methyl esters of fatty acids were added to samples before pyrolysis to superimpose peaks of known retention time on the pyrochromatograms. These peaks were useful in calibrating the retention time scales so that peaks on different chromatograms could be appropriately homologized. The study included 3 species of Nannizzia, 3 strains of Trichophyton rubrum and 1 strain each of Gymnoascus uncinatus, G. reesii, Arachniotus hyalinosporus, Chrysosporium pannorum and Gliocladium viride. Pyrograms of the 3 T. rubrum strains were not as similar to each other as the pyrograms of some of the supposedly distantly related species. Unless our identification of 1 or more of the T. rubrum strains is incorrect, these results cast doubt on the usefulness of pyrochromatograms as indicators of genetic similarity.

Ascomycota↗

PubMed2007

The conversion of chicken manure to biooil by fast pyrolysis I. Analyses of chicken manure, biooils and char by 13C and 1H NMR and FTIR spectrophotometry.

Fast pyrolysis of chicken manure produced two biooils (Fractions I and II) and a residual char. All four materials were analyzed by chemical methods, 13C and 1H Nuclear Magnetic Resonance Spectrometry (13C and 1H NMR), and Fourier Transform Infrared Spectrosphotometry (FTIR). The char showed the highest C content and the highest aromaticity. Of the two biooils Fraction II was higher in C, yield and calorific value but lower in N than Fraction I. The S and ash content of the two biooil fractions were low. The Cross Polarization Magic Angle Spinning (CP-MAS) 13C NMR spectrum of the initial chicken manure showed it to be rich in cellulose, which was a major component of sawdust used as bedding material. Nuclear Magnetic Resonance (NMR) spectra of the two biooils indicated that Fraction I was less aromatic than Fraction II. Among the aromatics in the two biooils, we were able to tentatively identify N-heterocyclics like indoles, pyridines, and pyrazines. FTIR spectra were generally in agreement with the NMR data. FTIR spectra of both biooils showed the presence of both primary and secondary amides and primary amines as well as N-heterocyclics such as pyridines, quinolines, and pyrimidines. The FTIR spectrum of the char resembled that of the initial chicken manure except that the concentration of carbohydrates was lower.

Animals↗

PubMed2006

Feasibility of soil dust source apportionment by the pyrolysis-gas chromatography/mass spectrometry method.

This study tested the feasibility of using pyrolysis (Py)-gas chromatography (GC)/mass spectrometry (MS) to obtain organic chemical species data suitable for source apportionment modeling of soil-derived coarse particulate matter (PM10) dust on ambient filters. A laboratory resuspension apparatus was used with known soils to generate simulated receptor filter samples loaded with approximately 0.4 mg of PM10 dust, which is within the range of mass loading on ambient filters. Py-GC/MS at 740 degrees C generated five times more resolvable compounds than were obtained with thermal desorption GC/MS at 315 degrees C. The identified compounds were consistent with literature from Py experiments using larger samples of bulk soils. A subset of 91 organic species out of the 178 identified Py products was used as input to CMB8 software in a demonstration of source apportionment using laboratory-generated mixtures simulating ambient filter samples. The 178 quantified organic species obtained by Py of soil samples is an improvement compared with the 38 organic species obtained by thermal desorption of soils and the four functionally defined organic fractions reported by thermal/ optical reflectance. Significant differences in the concentration of specific species were seen between samples from different sites, both geographically distant and close, using analysis of variance and cluster analysis. This feasibility study showed that Py-GC/MS can generate useful source profile data for receptor modeling and justifies continued method development.

Cluster Analysis↗

PubMed1989

Tissue localization of the carcinogenic glutamic acid pyrolysis product Glu-P-1 in control and beta-naphthoflavone-treated mice and rats.

Autoradiograms obtained after i.v. injection of the 14C-labelled carcinogenic glutamic acid pyrolysis product Glu-P-1 to mice and rats showed a pronounced uptake of radioactivity in the liver, kidney, thyroid and nasal mucosa. High concentrations of radioactivity were present in the bile and intestinal contents at short post-injection times. In the male rat, the Zymbal's gland and the preputial gland were identified as sites of high and specific binding at all post-injection times examined. The liver and nasal mucosa were identified as sites of retention of non-extractable radioactivity. In the pigmented mouse, Glu-P-1 and/or its metabolites were accumulated in melanin. Glu-P-1 is known to be activated by cytochrome P-448. Pretreatment with beta-naphthoflavone (a cytochrome P-448 inducer) did not change the tissue localization of radioactivity in either species except for the liver where the overall labelling was decreased. Neither did pretreatment of mice with the glutathione-depleting agent phorone change the distribution pattern significantly. However, combined pretreatments of mice with either phorone or beta-naphthoflavone and the cytochrome P-448 inhibitor 9-hydroxyellipticine resulted in an increased overall retention of radioactivity in the body.

Animals↗

PubMed1990

Detection of carcinogenic glutamic acid pyrolysis products in cigarette smoke condensate.

Carcinogenic glutamic acid pyrolysis products were measured in condensate of cigarette mainstream smoke by HPLC. These carcinogens were found to be present in all brands of filter-tipped cigarette analyzed. The mean levels of 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole and 2-aminodipyridol[1,2-a:3',2'-d]imidazole in the cigarette mainstream smoke were 0.66 and 0.63 ng/cig respectively.

Carcinogens↗

PubMed1982

Mutagens produced by the pyrolysis of opium and its alkaloids as possible risk factors in cancer of the bladder and oesophagus.

Samples of opium pipe scrapings (opium dross, called sukhteh locally), but not of crude opium, collected in an area with a high incidence of oesophageal cancer in north-east Iran, were shown to contain pro-mutagens, producing mostly frameshift mutations in Salmonella typhimurium strains TA1538 and TA98 after metabolic activation. Pyrolysis of opium and of its major alkaloid, morphine, yielded smoke condensates with mutagenic activities 10 and 100 times higher, respectively, than that of the sukhteh samples tested. Heterocyclic aromatic hydrocarbons and primary aromatic amines present at different concentrations in these three pyrolysates are considered to be the major active principles. Opium addiction has been implicated as a risk factor in bladder cancer in humans and the ingestion of opium pyrolysates, in conjunction with dietary deficiencies, may be related to the high incidence of oesophageal cancer in north-east Iran, although causality has not been established.

Alkaloids↗

PubMed1983

Distribution of the carcinogenic tryptophan pyrolysis product Trp-P-1 in control, 9-hydroxyellipticine and beta-naphthoflavone pretreated mice.

Autoradiograms obtained 1-4 h after i.v. injection of the 14C-labelled carcinogenic tryptophan pyrolysis product Trp-P-1 to albino and pigmented mice showed a pronounced uptake of radioactivity in the lymphatic system (thymus, lymph nodes, bone marrow and spleen), in the endocrine system (hypophysis, thyroid, adrenal medulla) and in the liver, kidney medulla and brain. High radioactivity was present in the excretory pathways, predominantly in the bile/intestinal contents. At longer post-injection times (24 h to 6 days) most of the labelled substance had left the tissues, except for the liver which still retained a high concentration of radioactivity. Trp-P-1 is known to be activated by cytochrome P-448. The uptake of radioactivity in the liver could be reduced by pretreatment with the cytochrome P-448 inhibitor 9-hydroxyellipticine suggesting that the observed accumulation of radioactivity in the liver was partly due to metabolites of Trp-P-1. After pretreatment with the cytochrome P-448 inducer beta-naphthoflavone, the administration of Trp-P-1 resulted in a highly selective accumulation of radioactivity in the lung parenchyma, exceeding all other tissues in the body. beta-Naphthoflavone pretreatment also increased the uptake of radioactivity in the kidney cortex and small intestinal mucosa. As indicated by a high labelling of the pigmented tissues of the maternal and fetal eye, the carcinogen and/or its metabolites were accumulated in melanin.

Alkaloids↗

PubMed1983

Ultrastructural and biochemical alterations induced by tryptophan pyrolysis products on rat hepatocytes in primary culture. I. Action on the transcriptional process.

Adult rat hepatocytes in primary culture were used to study the effect of tryptophan pyrolysis products on the transcriptional process. Hepatocytes were treated with 1, 5 and 10 micrograms/ml of 3-amino-1,4-dimethyl-5H-pyrido-[4,3-b]-indole (Trp-P-1) or 3-amino-1-methyl-5H-pyrido-[4,3-b]-indole (Trp-P-2) for 2 and 4 h. The ultrastructural study revealed the appearance of nucleolar microsegregation accompanied by a reduction in peri- and interchromatin fibrils and granules in hepatocytes exposed to 10 micrograms/ml of each pyrolysate for 1 or 2 h. Biochemical investigation showed that the incorporation of [3H]uridine into nuclear RNA of treated hepatocytes was strongly decreased. Time- and concentration-related inhibition have been established; however, the inhibitory effect of Trp-P-1 was always superior to that of Trp-P-2. The determination of Mg2+-dependent RNA polymerase activity in an in vitro system functioning with isolated rat liver nuclei incubated in the presence of Trp-P-1 or Trp-P-2 showed a 40% inhibition of this activity. After a 1-h exposure of hepatocytes to 5 and 10 micrograms/ml of Trp-P-1, the recovery of RNA synthesis capacity was complete by 2 h and that of normal ultrastructural aspect was achieved within 4 h. All these results indicated that Trp-P-1 and Try-P-2 acted at the nucleolar level by a blockade of pre-rRNA synthesis and at the extranucleolar by decreasing the ultrastructural RNP responsible for hnRNA synthesis.

Animals↗

PubMed1985

Syntheses of 5-phenyl-2-pyridinamine, a possibly carcinogenic pyrolysis product of phenylalanine, and some of its putative metabolites.

5-Phenyl-2-pyridinamine (PPA) is a pyrolysis product of phenylalanine, the presence of which has been demonstrated in broiled sardines. Since PPA is mutagenic in the Ames test and is structurally related to the aminobiphenyls, it has to be considered as potentially carcinogenic. In this study procedures for the synthesis of PPA and its possible metabolites were developed to make them available for biological studies. PPA was synthesized in one step from 2,5-pyridinediamine. However, this method is only suitable for the preparation of small amounts. Larger quantities were synthesized starting from 5-nitro-2-pyridinamine in four steps. PPA was also prepared via a six-step synthesis, starting from 6-amino-3-pyridinecarboxamide. This route was also used for the synthesis of tritiated PPA [( 3H]PPA) and 2-nitro-5-phenylpyridine, the latter being the precursor of the two putative proximate carcinogenic metabolites, viz. the hydroxylamine and the hydroxamic acid of PPA. In the course of these multi-step syntheses a new method for the preparation of unsymmetrical biaryls was worked out. The following possible metabolites were also synthesized: N-(5-phenyl-2-pyridinyl)acetamide in the course of the synthesis of PPA starting from 5-nitro-2-pyridinamine, and both 5-(4-hydroxyphenyl)-2-pyridinamine (4'-OH-PPA) and N-[5-(4-hydroxyphenyl)-2-pyridinyl]acetamide starting from 5-(4-aminophenyl)-2-pyridinamine. After incubation of PPA in suspensions of freshly isolated hepatocytes from rats pretreated with polychlorinated biphenyls (Aroclor 1254) or PPA itself, the presence of 4'-OH-PPA was demonstrated.

Aminopyridines↗

PubMed1988

In vitro and in vivo N-acetylation of carcinogenic glutamic acid pyrolysis products in humans.

The carcinogenic glutamic acid pyrolysis products, 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1) and 2-aminodipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2), and their N-acetyl derivatives have been demonstrated to be present in human urine, bile, liver and kidney. In vitro experiments have revealed that Glu-P-1 and Glu-P-2 are N-acetylated to form N-acetyl derivatives by the cytosolic fraction from a human autopsy liver specimen. From these results our data strongly suggest that Glu-P-1 and Glu-P-2 derived from everyday foods are partially N-acetylated in human organs and that they are excreted in bile and urine with their N-acetyl derivatives. Our data also provide the first reliable evidence that humans can metabolize the carcinogenic heterocyclic amines.

Acetylation↗

PubMed1976

Pyrolysis GLC identification of food and drug ingredients. II. Qualitative and quantitative analysis of penicillins and cephalosporins.

Pyrolysis gas-liquid chromatography (PGLC) provided reproducible pyrograms for 14 penicillins and cephalosporins studied which permitted direct characterization and differentiation of the antibiotics in almost all cases. The quantitative application of the technique was explored using four of the antibiotics. Standard curves were constructed based on the height of the most intense (and symmetrical) peak in the pyrograms. Excellent linearity was obtained in the ranges studied, 10 nanograms - 100 micrograms. Further quantitative application of the method is discussed.

Cephalosporins↗

PubMed1976

Pyrolysis GLC identification of food and drug ingredients. I. Saccharin.

Pyrolysis gas-liquid chromatography, used in the qualitative analysis of saccharin, has provided reproducible pyrograms which permit direct characterization of these sweetners in a variety of commerical saccharin tablets and diet beverages. This method was used also to identify the salt, after conversion to the free imide, in a commercial multivitamin product. The tablet analysis required isolation by solvent extraction. Analyses were carried out on quantities ranging from 1 to 100 mug. The sensitivity of the method could be increased by addition of a pure sample of the compound sought to the unknown.

Beverages↗

PubMed1978

Botulism: a pyrolysis-gas-liquid chromatographic study.

Forty samples of dried Clostridia bacteria were subjected to pyrolysis-gas-liquid chromatography (PGLC). Examination of the key fingerprint peaks enabled the analyst to differentiate the samples into their respective antigenic groups. Peaks occurring at the high boiling end of profile could be used to distinguish proteolytic from non-proteolytic strains of C-botulinum. PGLC has proven to be a highly reproducible as well as a rapid specific method for differentiating and identifying samples of Clostridium botulinum.

Botulism↗

PubMed1995

Analysis of Bacteroides species by pyrolysis mass spectrometry.

Two methods for the classification of isolates of the Bacteroides fragilis group were compared in a study of 133 clinical isolates and 10 reference strains. There was broad similarity between the pattern of clusters in pyrolysis mass spectrometry (PyMS), which reflects whole-cell composition, and that in conventional tests, which reflect nutritional interactions with the environment. A single large cluster was resolved by both approaches; this cluster comprised mainly strains identified as B. fragilis and was surrounded by a multiplicity of small clusters (42 in PyMS and 24 in conventional tests). Individual clusters corresponding to strains identified as Bacteroides thetaiotaomicron and Bacteroides vulgatus, respectively, were found by both techniques. However, for the remainder of strains, little correlation was evident between clustering in PyMS and that in conventional tests. Further comparison with data obtained by sodium dodecyl sulfate- polyacrylamide gel electrophoresis for this collection of strains showed equal levels of disagreement between classification based on whole-cell protein and each of the classifications described here. In previous studies of other genera, PyMS-based and conventional test-based classifications showed good agreement. It appears that the B. fragilis group presents intractable problems in phenotypic characterization.

Bacterial Typing Techniques↗

PubMedDate not supplied

Identification and quantification of phencyclidine pyrolysis products formed during smoking.

As a result of frequent phencyclidine (PCP) abuse, pyrolysis studies were conducted to further investigate its fate during smoking. Marijuana placebo cigarettes were impregnated with 3H-PCP X HCI and burned under conditions simulating smoking. Mainstream smoke was passed through glass wool filters as well as acidic and basic traps. Approximately 90% of the starting material could be accounted for in the first glass wool trap and cigarette holder. HPLC and GC/MS analysis of methanol extracts of these glass wool traps revealed the presence of 1-phenyl-1-cyclohexene (47% of the starting material) greater than PCP (40%) greater than piperidine (15%) greater than N-acetylpiperidine (9%). It was not possible to fully account for the remainder of the piperidine moiety. It has been reported that at high temperatures PCP is converted to numerous polynuclear aromatic compounds which include styrene, alpha-methylstyrene, naphthalene, 2-methylnaphthalene, 1-methylnaphthalene, biphenyl, cyclohexylbenzene, acenaphthene, phenanthrene, and anthracene. These compounds were not formed from PCP under smoking conditions.

Chromatography, High Pressure Liquid↗

PubMedDate not supplied

Pyrolysis and volatilization of cocaine.

The increasing popularity of inhaling cocaine vapor prompted the present study, to determine cocaine's fate during this process. The free base of [3H]cocaine (1 microCi/50 mg) was added to a glass pipe, which was then heated in a furnace to simulate freebasing. Negative pressure was used to draw the vapor through a series of glass wool, ethanol, acidic, and basic traps. Air flow rate and temperature were found to have profound effects on the volatilization and pyrolysis of cocaine. At a temperature of 260 degrees C and a flow rate of 400 mL/min, 37% of the radioactivity remained in the pipe, 39% was found in the glass wool trap, and less than 1% in the remainder of the volatilization apparatus after a 10-min volatilization. Reducing the air flow rate to 100 mL/min reduced the amount of radioactivity collected in the glass wool trap to less than 10% of the starting material and increased the amount that remained in the pipe to 58%. GC/MS analysis of the contents of the glass wool trap after volatilization at 260 degrees C and a flow rate of 400 mL/min revealed that 60% of the cocaine remained intact, while approximately 6 and 2% of the starting material was recovered as benzoic acid and methylecgonidine, respectively. As the temperature was increased to 650 degrees C, benzoic acid and methylecgonidine accounted for 83 and 89% of the starting material, respectively, whereas only 2% of the cocaine remained intact. Quantitation of cocaine in the vapor during the course of volatilization revealed high concentrations during the first two min and low concentrations for the remaining time.(ABSTRACT TRUNCATED AT 250 WORDS)

Benzoates↗

PubMedDate not supplied

A pyrolysis product, anhydroecgonine methyl ester (methylecgonidine), is in the urine of cocaine smokers.

A method using combined gas chromatography/mass spectrometry (GC/MS) for determination of the cocaine pyrolysis product anhydroecgonine methyl ester (AEME) in urine is described. Using this method, we found that human subjects who smoked cocaine under laboratory conditions excreted substantial amounts of AEME in their urine. Little, if any, AEME was excreted in the urine when the same subjects were administered cocaine by intravenous and intranasal routes. AEME may be a useful marker for cocaine (crack) smoking. The pharmacology of AEME is unknown. The possibility that AEME may play a role in the effects associated with cocaine smoking needs to be examined.

Administration, Intranasal↗