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PubMed1979

Characterization of normal human cells by pyrolysis gas chromatography mass spectrometry.

Differentiation of normal human cells has been accomplished by pyrolysis gas chromatography mass spectrometry. Normal cells from human kidney, spleen, liver and brain tissues have been pyrolyzed and the products chromatographically separated and characterized by mass spectrometry. Molecular pyrolysis products giving rise to the characteristic pyro-mass chromatograms include, but are not limited to, alkenes, alkanes, nitriles and various ring compounds. Single ion mass chromatograms as well as multiple ion mass chromatograms have been used to explore the characteristic differences between various tissue materials. A dynamic computer methodology for comparing pyro-mass chromatograms has been developed for use in automatic identification and classification of the human cellular material.

Brain↗

PubMed1986

Pyrolysis mass spectrometry of bacteria from infected human urine. I. Influence of culturing and antibiotics.

Curie-point pyrolysis mass spectrometry was performed on three bacterial isolates obtained from infected human urine using a novel, direct isolation method. Bacterial samples were analysed directly after isolation, as well as after free growth in broth and after exposure to solutions containing penicillin and gentamicin. The spectra of bacteria directly from urine showed no detectable contamination from urinary constituents. Discriminant analysis indicated genetic strain differences to be greater than the combined variances due to sample preparation or the growth phase. Characteristic biochemical changes related to growth or non-growth were detectable after only 2 h of incubation. The potential usefulness of pyrolysis mass spectrometry techniques for rapid susceptibility testing is discussed.

Anti-Bacterial Agents↗

PubMed1987

[The analysis of caramel colors. 1. Differentiation of classes of caramel coloring agents with Curie-point pyrolysis-capillary gas chromatography-mass spectrometry].

After an introduction on the production, classification, legislative regulations, toxicology, and analysis of caramel colours, a report is given on the examination of these colourings by Curie-point pyrolysis-capillary gas chromatography-mass spectrometry. This method enables the differentiation between the four classes of caramel colours on the basis of the most concentrated of more than 100 identified pyrolysis products, which requires small quantities of substance (100 micrograms) and short periods of time (1 h).

Carbohydrates↗

PubMed1978

[High frequency pyrolysis of selected carbohydrates (author's transl)].

Glucose, amylose, amylopectin, cellulose, fructose, inulin, saccharose, celluloseacetate and methyl-cellulose were treated by High Frequency Pyrolysis (Curie Point Pyrolysis) at 700 degrees C. Volatile compounds formed by this process were separated by gas chromatography and the structures determined by GC/MS.

Amylopectin↗

PubMedDate not supplied

Analysis of human plasma as an exposure level monitor for carcinogenic tryptophan pyrolysis products.

A high-performance liquid chromatography method for detecting 3-amino-1,4- dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) in human plasma was developed. Plasma samples of 10 normal subjects were examined. Trp-P-1 and Trp-P-2, carcinogenic tryptophan pyrolysis products, were detected in all specimens, and the concentrations of Trp-P-1 and Trp-P-2 in plasma were 68.31 +/- 24.03 fmoles/ml (mean +/- S.D., n = 10) and 18.79 +/- 4.99 fmoles/ml, respectively. Our results suggest that plasma levels of carcinogenic tryptophan pyrolysis products may be useful indicators for estimating the exposure levels of the dietary carcinogens.

Adult↗

PubMed1991

Rapid inter-strain comparison by pyrolysis mass spectrometry in nosocomial infection with Xanthomonas maltophilia.

Seventeen strains of Xanthomonas maltophilia and one strain of Pseudomonas cepacia were examined by pyrolysis mass spectrometry (PYMS). The Xanthomonas strains comprised 11 clinical and environmental isolates from a suspected outbreak of colonization and infection on a heart-lung transplant intensive care unit, two strains from patients elsewhere in the same hospital and four strains from a national reference collection. The single isolate of Pseudomonas cepacia was from a sink in the same affected intensive care unit. A series of discriminant analyses performed on the PYMS-derived data showed that, whereas six strains of Xanthomonas from the respiratory tract, blood and ventilatory equipment of one of the affected patients were indistinguishable, all the other isolates were distinct. The results of PYMS rapid inter-strain comparison were in accord with those of an epidemiological investigation which suggested that the episode was due to unauthorized reuse of disposable nebulizers and not to cross-infection between patients. Pyrolysis mass spectrometry with rapid data analysis is a potentially useful technique for the investigation of nosocomial infections due to organisms such as X. maltophilia.

Bacteriological Techniques↗

PubMed1992

Pyrolysis mass spectrometry as a method for the classification, identification and selection of actinomycetes.

Pilot experiments were designed to determine the potential of Curie-point pyrolysis mass spectrometry (PyMS) in the classification, identification and typing of industrially significant actinomycetes, and for the detection of target and novel actinomycetes needed for pharmacological screening programmes. The results indicate that the method is of value for the separation of actinomycetes at and below the species level, in the detection and circumscription of novel actinomycetes, and for the detection of identical and duplicated strains. There is also evidence that the pyrolysis system will permit the identification of target actinomycetes directly from selective isolation plates. PyMS is one of the methods that should be used to generate polyphasic taxonomies of actinomycete genera.

Actinomycetales↗

PubMed1991

Gas chromatographic-mass spectrometric analysis of tar compounds formed during pyrolysis of rice husks.

Pyrolysis of agricultural waste to produce fuel gas involves formation of tars as noxious by-products. In this paper the qualitative analysis of tars formed during pyrolysis of rice husks is presented, based on identification by gas chromatography-mass spectrometry and interpolation of retention times on a polyaromatic hydrocarbon index scale. The influence of some reaction parameters on product formation is briefly discussed.

Gas Chromatography-Mass Spectrometry↗

PubMed1991

Analysis of methylbenactyzium bromide in human urine by thin-layer chromatography and pyrolysis gas chromatography.

A rapid and simple method of utilizing thin-layer chromatography (TLC) and pyrolysis gas chromatography (PyGC) for the identification and determination of methylbenactyzium bromide in human urine was studied in this report. Methylbenactyzium bromide was extracted from urine with ODS-cartridge (Sep-Pak C18), then spotted onto a silica gel 60 F254 TLC plate. After development, the separated spot of methylbenactyzium bromide was scraped and wrapped with a ferromagnetic foil without extraction by any organic solvents. The sample was applied into PyGC analysis. The optimum temperature for pyrolysis was 590 degrees C. The main degradation product of methylbenactyzium bromide was identified as diphenylmethane in this procedure by gas chromatography/mass spectrometry (GC/MS). A calibration graph prepared by absolute calibration method showed a good linearity over the concentration range of 1-75 micrograms/spot for methylbenactyzium bromide. The coefficient of variation obtained for eleven replicate analyses of the 3 micrograms/spot of standard methylbenactyzium bromide was 3.8%. The detection limit of this compound by this procedure was 0.1 micrograms/spot.

Calibration↗

PubMed1989

Sonochemistry of nitrone spin traps in aqueous solutions. Evidence for pyrolysis radicals from spin traps.

When argon-saturated aqueous solutions of alpha-phenyl-N-tert-butylnitrone (PBN) were sonicated, the spin adducts PBN-Phenyl (Ph), PBN-X, and PBN-H were observed. It can be inferred that PBN-Ph and -X arise from spin adducts of thermal decomposition products of PBN induced by the high temperature due to ultrasonic cavitation. The ESR signal of PBN-H was observed at a lower PBN concentration than those of PBN-Ph and PBN-X. The ratios of ESR intensity of PBN-H to those of PBN-Ph and PBN-X increased with the final temperatures of the cavitation bubbles created by different rare gases. The spin adducts of methyl and tert-butyl radicals from the pyrolysis of PBN, induced by the high temperatures due to cavitation, were found from spin trapping experiments in which 3,5-dibromo-2,6-dideuterio-4-nitrosobenzene sulfonate was used as a spin trap. Similar spin adducts induced by pyrolysis were also observed in sonicated aqueous solutions of other nitrone spin traps, such as alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone, and alpha-(4-nitrophenol) N-tert-butylnitrone. The greater the hydrophobicity of the spin traps, as measured by the 2-octanol/water partition coefficients, the lower the concentration of spin trap at which methyl radicals generated by thermal decomposition of the spin trap can be observed. The present results indicate that the nonvolatile, highly hydrophobic spin traps accumulate preferentially in the interfacial region of cavitation bubbles where they undergo thermal decomposition during cavitation to produce the radicals.

Chemical Phenomena↗

PubMed1989

Carcinogenic tryptophan pyrolysis products in human lens.

Mutagenic and carcinogenic tryptophan pyrolysis products, 3-amino-1,4-dimethyl-5H-pyrido-[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), have been identified in human cataractous lenses, but not in young bovine lenses. The amounts of Trp-P-1 and Trp-P-2 in senile cataractous lenses were 156.34 +/- 35.63 fmol (mean +/- S.D., n = 10) and 128.27 +/- 40.45 fmol (n = 10), respectively, while those of Trp-P-1 and Trp-P-2 in diabetic cataractous lenses were 158.29 +/- 40.06 fmol (n = 10) and 150.34 +/- 23.77 fmol (n = 10), respectively. In both senile and diabetic cataractous lenses, the concentrations of Trp-P-1 and Trp-P-2 in the insoluble protein fraction (fmol mg-1 protein) were significantly higher than those in the water-soluble protein fraction. Moreover, proteinase-K treatment of lens protein before extraction with methylene chloride significantly increased the recoveries of Trp-P-1 and Trp-P-2. These results clearly indicate that carcinogenic tryptophan pyrolysis products, gamma-carboline derivatives, are present in human cataractous lenses and that these fluorescent carcinogens are significantly concentrated in the insoluble lens proteins.

Adult↗

PubMed1986

Identification of soy protein in meat by pyrolysis-high-resolution gas chromatography.

Pyrolysis-gas chromatography was applied to the characterization of ground beef and soy protein isolate and its mixtures at the 50, 30 and 10% levels. A cryogenic trap pyrolysis mode was employed and the volatile pyrolysates were analysed by a high-resolution capillary gas chromatograph. Two phenolic derivatives, o-methoxy- and dimethoxyphenol, as well as 2,3-dithiabutane are uniquely observed at a large concentration in the soy pyrolysate. Quantification of these characteristic compounds allow the estimation of the level of soy inclusion in the mixture. This approach effectively denotes soy addition up to the 10% level in comminuted beef.

Animals↗

PubMed1990

Direct analysis of bacterial fatty acids by Curie-point pyrolysis tandem mass spectrometry.

Although pyrolysis-mass spectrometry (Py-MS) has been used for bacterial taxonomy, many of the mass spectral peaks used for discrimination of organisms have not been correlated to known biomolecules. This work presents the discrimination of five bacterial species based on Py-MS patterns containing only peaks that can be correlated to fatty acids and fatty acid derivatives. These correlations were confirmed by pyrolysis-tandem mass spectrometry of authentic standards and the organisms. The pattern recognition procedures used gave better results when only the fatty acid peaks were used in the analysis than when full spectra were used.

Bacillus↗

PubMed1990

Characterization of underivatized lipid biomarkers from microorganisms with pyrolysis short-column gas chromatography/ion trap mass spectrometry.

A microvolume Curie-point pyrolysis short-column (5 m) gas chromatography/mass spectrometry (Py-GC/MS) procedure was developed for the characterization of various lipid moieties in microorganisms. High linear flow rates (approximately 175 cm/s) characterized the GC conditions in order to effect an efficient chromatographic transfer and elution of the underivatized diglycerides and monoglycerides, and small modifications were necessary to the ion trap MS system in order for it to accommodate the relatively high gas load. During a typical analysis run anhydrodiacylglycerides eluted within a 5-6-min time frame. Gram-positive bacilli and Gram-negative species were differentiated from each other by the pyrolysis patterns of their lipid components. In spite of the complexity of the analyte, a straightforward visual analysis was achieved with the aid of simple computerized data display procedures. These procedures included examination of (1) total ion current (TIC) profiles of the lipid region of the reconstructed chromatogram, (2) the integrated mass spectrum of this region, (3) selected reconstructed ion chromatograms (RICs), (4) RIC intensity distributions, and (5) corresponding mass spectra. An appealing aspect of the lipid data reduction procedure is that most of it can be accomplished visually without requiring computerized pattern recognition techniques.

Bacteria↗

PubMed1975

Polyvinyl chloride pyrolysis products. A potential cause for respiratory impairment.

A limited investigation of respiratory and other symptom prevalence, plus before and after shift ventilatory capacity was conducted among a group of 17 meat wrappers exposed to pyrolysis products of polyvinyl chloride and a group of 21 control subjects. Exposed meat wrappers showed a higher prevalence of cough, phlegm, hay fever, and asthma than did the control group. The exposed group also demonstrated relative decreases in forced expiratory volume, one second (FEV1.0) and forced expiratory flow 50% (FEF50) after one shift of work; whereas, the controls showed an opposite tendency. These findings suggest that meat wrappers exposed to pyrolysis products of polyvinyl chloride might be adversely affected. The results, while suggestive, are not totally conclusive owing to the fact that there was not ideal matching of the exposed and control groups in regard to age, height, race, sex, and smoking status.

Age Factors↗

PubMed1978

Pyrolysis gas chromatography of enzymes.

Pyrolysis gas chromatography (PGC) has been shown to be useful for differentiating enzymes. The enzymes alpha-chymotrypsin, lactate dehydrogenase, catalase, and urease were easily "fingerprinted" on a 1.8 m 0.5% Carbowax 20 M column. Also, in some cases, isoenzymes of lactate dehydrogenase could be distinguished. Based on the pyrolyses of the free aromatic amino acids, four major enzyme pyrolysis peaks were tentatively identified as organic compounds derived from tyrosine and tryptophan. The use of a nitrogen-selective detector in conjunction with the FID and measurement of peak retention times by computer on three different types of columns permitted confirmations of peak identity.

Acetylcholinesterase↗

PubMed1986

Pyrolysis gas chromatography-mass spectrometry of mycobacterial mycolic acid methyl esters and its application to the identification of Mycobacterium leprae.

Pyrolysis gas chromatography-mass spectrometry of methyl mycolates from 32 species of mycobacteria, including Mycobacterium leprae, was carried out. The mycobacteria could be classified into four groups in respect of the fatty acid ester patterns detected within the range C20 to C26. The applicability of this pyrolysis-gas chromatographic method for identifying M. leprae is discussed.

Chromatography, Gas↗

PubMed1989

A pyrolysis mass spectrometry study of fusobacteria.

Strains of fusobacteria (143) were examined by pyrolysis mass spectrometry (Py-MS) with a Horizon Instruments PYMS 200X. Fusobacterium necrogenes, F. necrophorum, F. nucleatum, F. mortiferum, F. varium, F. gonidiaformans, F. naviforme, F. russii and Leptotrichia buccalis were discriminated. Strains of fusobacteria isolated from tropical ulcers, although similar to F. mortiferum in conventional tests, were discriminated from each of these species in Py-MS. Identification of 416 spectra to species level agreed with conventional bacteriological methods in 91.8% of cases, was equivocal in 3.4% and disagreed in 4.8%. Classification based on pyrolysis data resolved groups largely corresponding to the recognised species. However, F. nucleatum strains were divided between two distinct groups. The tropical ulcer strains were resolved as a distinct homogeneous group. Py-MS is a rapid, inexpensive and convenient procedure for characterisation of bacteria, with the capacity for a high throughput of samples, although the initial cost of the apparatus is high.

Fusobacterium↗