Attempt to approach the role of phenolic phenylpropenol structures in the photoyellowing of softwood mechanical pulps

2002 ◽  
Vol 80 (9) ◽  
pp. 1223-1231 ◽  
Author(s):  
Brigitte Ruffin ◽  
Stéphane Grelier ◽  
Aziz Nourmamode ◽  
Alain Castellan
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Ferulic Acid ◽  
Sodium Borohydride ◽  
Coniferyl Alcohol ◽  
Gas Chromatography Mass Spectrometry ◽  
Mechanical Pulp ◽  
Bleached Pulp ◽  
Mechanical Pulps

Three biphenyl (I, II, III) compounds and a benzylarylether (IV) compound were synthesized to detect and quantify the presence of phenolic phenylpropenols in unbleached, peroxide-bleached, or sodium borohydride-reduced mechanical softwood pulps. The methodology used is based on a gas chromatography – mass spectrometry search of the prepared compounds in the residue obtained after ethylation, thioacidolysis, and desulfurization of the pulps. Detection of biphenyl I ([Formula: see text]4 × 10–6 mol g–1) in unbleached and NaBH4-reduced pulps is indicative of the presence of phenolic coniferaldehyde units in these pulps. Traces of biphenyl II, found in the peroxide-bleached pulp, probably came from ferulic acid units formed by oxidation of coniferaldehyde by H2O2. No biphenyl ether III or benzylaryl ether IV were detected in the three pulps. This result indicates that phenolic phenylpropenol units are not present in softwood mechanical pulps and do not contribute to the fast part of their photoyellowing.Key words: mechanical pulp, photoyellowing, phenol, coniferyl alcohol, biphenyl.

scholarly journals Determination of Mammalian Lignans in Biological Samples by Modified Gas Chromatography/Mass Spectrometry

2007 ◽  
Vol 90 (3) ◽  
pp. 641-646 ◽  
Author(s):  
Ajay Bommareddy ◽  
Bhanu L Arasada ◽  
Duane P Mathees ◽  
Chandradhar Dwivedi
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
Serum Samples ◽  
Selected Ion Monitoring ◽  
Beneficial Effects ◽  
Chromatography Mass Spectrometry ◽  
Flaxseed Meal

Abstract Lignans in flaxseed have been part of the human diet for centuries. In 1955, the isolation and structure of the lignan derivative secoisolariciresinol diglucoside (SDG) was reported. The biological role of SDG and mammalian lignan metabolites enterodiol and enterolactone was initially reported 20 years later. Experimental evidences showed the beneficial effects of lignans on breast, colon, and thyroid cancer. A modified gas chromatography/mass spectrometry (GC/MS) assay was developed for lignans in serum and colon samples of rats fed flaxseed meal. The method developed for the analysis of metabolites involves extraction and derivatization of samples and quantitative analysis by selected ion monitoring using GC/MS. The levels of lignan metabolites enterodiol and enterolactone were determined to be 0.013 and 0.23 M in serum samples and 0.008 and 1.63 M in colon samples.

scholarly journals Diagnosis of COVID-19 by exhaled breath analysis using gas chromatography-mass spectrometry

2021 ◽  
pp. 00139-2021
Author(s):  
Wadah Ibrahim ◽  
Rebecca L. Cordell ◽  
Michael J. Wilde ◽  
Matthew Richardson ◽  
Liesl Carr ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Area Under The Curve ◽  
Gas Chromatography Mass Spectrometry ◽  
Exhaled Breath ◽  
Non Invasive ◽  
Clinical Probability ◽  
Chromatography Mass Spectrometry ◽  
Exhaled Breath Analysis

BackgroundThe ongoing COVID-19 pandemic has claimed over two and a half million lives worldwide so far. SARS-CoV-2 infection is perceived to be seasonally recurrent and a rapid non-invasive biomarker to accurately diagnose patients early-on in their disease course will be necessary to meet the operational demands for COVID-19 control in the coming years.ObjectiveTo evaluate the role of exhaled breath volatile biomarkers in identifying patients with suspected or confirmed COVID-19 infection, based on their underlying PCR status and clinical probability.MethodsA prospective, real-world, observational study recruiting adult patients with suspected or confirmed COVID-19 infection. Breath samples were collected using a standard breath collection bag, modified with appropriate filters to comply with local infection control recommendations and samples were analysed using gas chromatography-mass spectrometry (TD-GC-MS).Findings81 patients were recruited between April 29th to July 10th, 2020, of whom 52/81 (64%) tested positive for COVID-19 by RT-PCR. A regression analysis identified a set of seven exhaled breath features (benzaldehyde, 1-propanol, 3, 6-methylundecane, camphene, beta-cubebene, Iodobenzene, and an unidentified compound) that separated PCR positive patients with an area under the curve (AUC): 0.836, sensitivity: 68%, specificity: 85%.ConclusionsGC-MS detected exhaled breath biomarkers were able to identify PCR positive COVID-19 patients. External replication of these compounds is warranted to validate these results.

Severe isopropanolemia without acetonemia or clinical manifestations of isopropanol intoxication

1993 ◽  
Vol 39 (9) ◽  
pp. 1922-1925 ◽  
Author(s):  
K M Chan ◽  
E T Wong ◽  
W S Matthews
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Serum Concentration ◽  
Half Life ◽  
Clinical Manifestations ◽  
Gas Chromatography Mass Spectrometry ◽  
Toxicological Analysis ◽  
Chromatography Mass Spectrometry ◽  
Osmolal Gap

Abstract This is the first reported case of severe isopropanolemia in a patient who did not experience associated clinical manifestations and acetonemia. The patient was found lying face down in a hotel lobby but at admission was alert and oriented to place and person. Toxicological analysis of the patient's serum revealed the presence of isopropanol at a concentration of 72 mmol/L. An increased serum osmolal gap (81 mOsm/kg) was also observed. The serum concentration of isopropanol decreased to 9.5 mmol/L 15.5 h after admission with an estimated half-life of elimination of 5-7 h. No serum acetone was detected throughout the patient's hospitalization. The identity of isopropanol was confirmed by gas chromatography/mass spectrometry. The patient remained awake and alert while in the hospital and was discharged 5 days after admission. These unusual findings raise some fundamental questions about the role of isopropanol conversion to acetone in the manifestation of symptoms usually associated with isopropanol intoxication.

Host-plant finding by the asparagus fly, Plioreocepta poeciloptera (Diptera: Tephritidae), a monophagous, monovoltine tephritid

2005 ◽  
Vol 95 (5) ◽  
pp. 393-399 ◽  
Author(s):  
É Thibout ◽  
D. Pierre ◽  
N. Mondy ◽  
C. Lecomte ◽  
J.C. Biémont ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Circadian Rhythm ◽  
Host Plant ◽  
Behavioural Response ◽  
Gas Chromatography Mass Spectrometry ◽  
Male Pheromone ◽  
Pest Insect ◽  
Age And Sex

AbstractThe role of various olfactory and visual stimuli was studied in host-plant finding by the asparagus fly Plioreocepta poeciloptera (Schrank), a monophagous monovoltine tephritid causing serious damage to asparagus spears. Volatiles released by asparagus plants were extracted by diethyl ether after cryotrapping concentration, and identified by gas chromatography–mass spectrometry. Twelve of the 13 compounds identified were tested using electroantennography to measure the response of the fly. Behavioural response was analysed using two different flight tunnels according to circadian rhythm, age and sex of adults, presence of the plant and of different coloured lures, presence of a male congener, or exposure to four pure asparagus odour compounds that elicited responses in electroantennography, i.e. hexanal, (E)-2-hexenal, (Z)-2-hexen-1-ol and decanal. Data showed that males locate the host plant more quickly than females. Females are attracted mainly by the blend of plant odour and male pheromone. Both sexes respond to a complex of stimuli only during the afternoon. These findings will be helpful in developing new and effective approaches to control this pest insect.

Gas Chromatography Mass Spectrometry: A Report on the State of the Art

1974 ◽  
Vol 28 (4) ◽  
pp. 305-317 ◽  
Author(s):  
Catherine Fenselau
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Mass Spectrometer ◽  
Isotope Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Gas Chromatograph ◽  
Chromatography Mass Spectrometry ◽  
Pharmacology And Toxicology ◽  
Computerized Data Processing

Instrumental and technical aspects of the combination gas chromatograph mass spectrometer are discussed, with emphasis on the various ways in which the mass spectrometer can serve as a detector for the gas chromatograph. A number of examples of applications are presented, in which the gas chromatograph mass spectrometer is used in its various instrumental modes. Computerized data processing is reviewed, and examples of applications are presented. Most of the examples of applications are taken from pharmacology and toxicology. Special attention is given to stable isotope analysis and to the role of stable isotopes in quantitation by gas chromatography mass spectrometry of samples in the subnanogram range.

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