GC×GC-FID Dotaz Zobrazit nápovědu
Determination of olefins in pyrolysis oils from waste plastics and tires is crucial for optimizing the pyrolysis process and especially for the further advanced valorization of these oils in terms of the circular economy. Identifying olefins, even using high-resolution techniques like GC×GC, is challenging without TOF-MS, which allows modification of the ionization step. Currently, the only method for determining olefins in plastic pyrolysis oils is GC-VUV, recently standardized as ASTM D8519. However, TOF-MS and VUV are not affordable instruments for many research teams working on plastics recycling. This paper introduces a simple method for the selective micro-scale adsorption of olefins over AgNO3/SiO2, followed by the GC×GC-FID analysis. Olefins are determined indirectly from the loss of chromatographic area in respective hydrocarbon groups before and after removal. Only 50 μL sample and 15 min of sample separation are needed. Our method was extensively validated and provides a reliable determination of olefin content in a wide range of pyrolysis oils from plastics and tires and their products after mild hydrotreatment. It is affordable to all researchers and industrial companies working on plastics recycling by thermochemical processes as it does not require an MS detector.
- Klíčová slova
- Determination, GC×GC-FID, Olefins, Plastics, Pyrolysis Oil, Tires,
- Publikační typ
- časopisecké články MeSH
Liquid transportation fuels in the middle distillate range contain thousands of hydrocarbons making the predictions and calculations of properties from composition a challenging process. We present a new approach of hydrogen content determination by comprehensive two-dimensional gas chromatography with flame ionization detector (GC×GC-FID) using a weighted average method. GC×GC-FID hydrogen determination precision was excellent (0.005 wt% repeatability). The method accuracy was evaluated by high-resolution nuclear magnetic resonance (NMR) technique, which is non-biased, measures the H signal directly and was independently validated by controls in the current study. The hydrogen content (in the range of 12.72-15.54 wt%) in 28 fuel samples were determined using GC×GC-FID. Results were within ± 2% of those obtained via NMR. Owing to the fact that NMR is accepted as an accurate technique for hydrogen content determination, the GC×GC method proposed in this study can be considered precise and accurate.
- Klíčová slova
- Aviation jet fuel, Diesel, GC×GC, Hydrogen content, NMR,
- Publikační typ
- časopisecké články MeSH
A new arrangement of the INCAT (inside needle capillary adsorption trap) device with Carbopack X and Carboxen 1000 as sorbent materials was applied for sampling, preconcentration and injection of C6C19n-alkanes and their monomethyl analogs in exhaled breath samples. For the analysis both GC-MS/MS and GC×GC-FID techniques were used. Identification of the analytes was based on standards, measured retention indices and selective SRM transitions of the individual isomers. The GC-MS/MS detection limits were in the range from 2.1 pg for n-tetradecane to 86 pg for 5-methyloctadecane. The GC×GC-FID detection limits ranged from 19 pg for n-dodecane to 110 pg for 3-methyloctane.
- Klíčová slova
- Exhaled breath, INCAT, Monomethylalkanes, Needle trap, n-Alkanes,
- MeSH
- alkany analýza chemie MeSH
- dechové testy metody MeSH
- lidé MeSH
- limita detekce MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí metody MeSH
- reprodukovatelnost výsledků MeSH
- tandemová hmotnostní spektrometrie metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- alkany MeSH
The social concern about polycyclic aromatic hydrocarbons (PAHs) is due to the awareness that several of them are carcinogens and are present in polluted air. Several epidemiological investigations have tried to assess the influence of air pollution on the incidence in the population (1). Some authors have suggest that 1-10% of the incidence of lung cancer is caused by air pollution (2, 3). Several sources, e.g. traffic, oil heating, wood stoves, industry may contribute PAHs to the air pollution. Therefore continuous air pollution control applying selective and precise analytical procedures is needed. The submitted work presents results of examination of sixteen polycyclic aromatic hydrocarbons [naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, chrysene, benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene, dibenzo(a, h)anthracene, benzo(ghi)perylene] settled on particles of 10 microns fractions of ashes, emitted from industrial and communication sources. Samples of suspended dust were collected at twelve measuring points, from May to June 1998, in 24-hour cycles, in accordance with US EPA methodology. PAHs were extracted from suspended dust in a Soxhlet apparatus and then exposed to extraction in a liquid-solid system (solid extraction-SPE) to eliminate redundant pollution, which may interfere with compounds by determined analysis. Samples were then analyzed using by capillary gas chromatographs "Varian" model 3400 with FID and MS detectors. Results of analysis make it possible to determine the influence of industry and traffic on atmospheric pollution, to compare results of two analytical methods (GC-FID and GC-MS).
- MeSH
- chromatografie plynová metody MeSH
- látky znečišťující vzduch analýza MeSH
- polycyklické sloučeniny analýza MeSH
- prach analýza MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Polsko MeSH
- Názvy látek
- látky znečišťující vzduch MeSH
- polycyklické sloučeniny MeSH
- prach MeSH
OBJECTIVES: The aim of this study was to develop and validate a gas chromatographic method with flame ionization detection (GC-FID) for the measurement of ibuprofen, naproxen and ketoprofen for clinical toxicology purposes. DESIGN AND METHODS: 100μL of plasma was treated with methyl chloroformate and derivatized analytes were extracted with hexane. Optimal conditions of the derivatization procedure have been found using the experimental chemometric design (face-centered central composite design). The selectivity and efficiency of the procedure was confirmed by GC-MS. RESULTS: The assay was linear in the concentration range of 10-400μgmL(-1), with adequate accuracy and precision for GC-FID (98-106.7%, CV≤9.1%, respectively) and for GC-MS (99.3-105.5%, CV≤9.2%, respectively). CONCLUSION: The entire sample preparation procedure is completed within 5 min and the quantitative results are available within 35 min. The method was successfully applied to quantify the selected compounds in serum of patients from emergency units.
- Klíčová slova
- Chloroformate, Experimental design, GC, Non-steroidal anti-inflammatory drugs,
- MeSH
- chromatografie plynová metody MeSH
- ibuprofen krev MeSH
- ketoprofen krev MeSH
- lidé MeSH
- naproxen krev MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- validační studie MeSH
- Názvy látek
- ibuprofen MeSH
- ketoprofen MeSH
- naproxen MeSH
This research provides an accurate description of the origin for fruit spirits. In total, 63 samples of various kinds of fruit spirits (especially from apples, pears, plums, apricots and mirabelle) were analysed using headspace-solid phase microextraction and gas chromatography with flame-ionization detector. Obtained volatile profiles were treated and analysed by multivariate regression with a reduction of dimensionality-orthogonal projections to latent structure for the classification of fruit spirits according to their fruit of origin. Basic result of statistical analysis was the differentiation of spirits to groups with respect to fruit kind. Tested kinds of fruit spirits were strictly separated from each other. The selection was achieved with a specificity of 1.000 and a sensitivity of 1.000 for each kind of spirit. The statistical model was verified by an external validation. Hierarchical cluster analysis (calculation of distances by Ward's method) showed a similarity of volatile profiles of pome fruit spirits (apple and pear brandies) and stone fruit spirits (especially mirabelle and plum brandies).
- MeSH
- alkoholické nápoje analýza MeSH
- chromatografie plynová metody MeSH
- mikroextrakce na pevné fázi metody MeSH
- ovoce chemie MeSH
- plamínková ionizace metody MeSH
- shluková analýza MeSH
- těkavé organické sloučeniny analýza MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- těkavé organické sloučeniny MeSH
A simple, cost-effective headspace gas chromatography (GC) method coupled with GC with flame ionization detection for simultaneous determination of methanol, ethanol and formic acid was developed and validated for clinical and toxicological purposes. Formic acid was derivatized with an excess of isopropanol under acidic conditions to its volatile isopropyl ester while methanol and ethanol remained unchanged. The entire sample preparation procedure is complete within 6 min. The design of the experiment (the face-centered central composite design) was used for finding the optimal conditions for derivatization, headspace sampling and chromatographic separation. The calibration dependences of the method were quadratic in the range from 50 to 5,000 mg/L, with adequate accuracy (89.0-114.4%) and precision (<12%) in the serum. The new method was successfully used for determination of selected analytes in serum samples of intoxicated patients from among those affected by massive methanol poisonings in the Czech Republic in 2012.
- MeSH
- chromatografie plynová MeSH
- ethanol krev moč MeSH
- formiáty krev moč MeSH
- kalibrace MeSH
- lidé MeSH
- methanol krev moč MeSH
- plamínková ionizace MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- ethanol MeSH
- formiáty MeSH
- formic acid MeSH Prohlížeč
- methanol MeSH
A simple, cost effective, and fast gas chromatography method with flame ionization detection (GC-FID) for simultaneous measurement of ethylene glycol, 1,2-propylene glycol and glycolic acid was developed and validated for clinical toxicology purposes. This new method employs a relatively less used class of derivatization agents - alkyl chloroformates, allowing the efficient and rapid derivatization of carboxylic acids within seconds while glycols are simultaneously derivatized by phenylboronic acid. The entire sample preparation procedure is completed within 10 min. To avoid possible interference from naturally occurring endogenous acids and quantitation errors 3-(4-chlorophenyl) propionic acid was chosen as an internal standard. The significant parameters of the derivatization have been found using chemometric procedures and these parameters were optimized using the face-centered central composite design. The calibration dependence of the method was proved to be quadratic in the range of 50-5000 mg mL(-1), with adequate accuracy (92.4-108.7%) and precision (9.4%). The method was successfully applied to quantify the selected compounds in serum of patients from emergency units.
- Klíčová slova
- Chloroformate, Experimental design, GC, Glycolic acid, Glycols,
- MeSH
- chromatografie plynová metody MeSH
- ethylenglykol krev otrava moč MeSH
- glykoláty krev otrava moč MeSH
- lidé MeSH
- plamínková ionizace metody MeSH
- propylenglykol krev otrava moč MeSH
- sérum chemie MeSH
- studie případů a kontrol MeSH
- toxikologie metody MeSH
- urgentní zdravotnické služby * MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Názvy látek
- ethylenglykol MeSH
- glycolic acid MeSH Prohlížeč
- glykoláty MeSH
- propylenglykol MeSH
Extensive traditional use of medical plants leads to research dealing with chemical composition of essential oils. The aim of this work was evaluation of quality of the essential oil and extending of the knowledge about chemical composition of essential oil from ribwort (Plantago lanceolata L.) and proportional representation of compounds. Extractions of essential oils from samples of ribwort were performed by hydrodistillation. GC-MS and GC-FID techniques were used for investigation of the qualitative and semi-quantitative content of aromatic compounds in the essential oils, respectively. Major aroma constituents of ribwort leaves were groups of fatty acids 28.0-52.1 % (the most abundant palmitic acid 15.3-32.0 %), oxidated monoterpenes 4.3-13.2 % (linalool 2.7-3.5 %), aldehydes and ketones 6.9-10.0 % (pentyl vinyl ketone 2.0-3.4 %) and alcohols 3.8-9.2 % (1-octen-3-ol 2.4-8.2 %). In relative high amount were identified apocarotenoids (1.5-2.3 %) which are important constituents because of their intense fragrant. The importance is in potential manufacture control of feedstocks before producing of food supplements.
- Klíčová slova
- Essential oil, GC-FID, GC-MS, Hydrodistillation, Plantago lanceolata L.,
- Publikační typ
- časopisecké články MeSH
INTRODUCTION: Cannabinoids are organic compounds, natural or synthetic, that bind to the cannabinoid receptors and have similar pharmacological properties as produced by the cannabis plant, Cannabis sativa. Gas chromatography (GC), e.g. gas chromatography mass spectrometry (GC-MS), is a popular analytical tool that has been used extensively to analyse cannabinoids in various matrices. OBJECTIVE: To review published literature on the use of various GC-based analytical methods for the analysis of naturally occurring cannabinoids published during the past decade. METHODOLOGY: A comprehensive literature search was performed utilising several databases, like Web of Knowledge, PubMed and Google Scholar, and other relevant published materials including published books. The keywords used, in various combinations, with cannabinoids being present in all combinations, in the search were cannabinoids, Cannabis sativa, marijuana, analysis, GC, quantitative, qualitative and quality control. RESULTS: During the past decade, several GC-based methods for the analysis of cannabinoids have been reported. While simple one-dimensional (1D) GC-MS and GC-FID (flame ionisation detector) methods were found to be quite common in cannabinoids analysis, two-dimensional (2D) GC-MS as well as GC-MS/MS also were popular because of their ability to provide more useful data for identification and quantification of cannabinoids in various matrices. Some degree of automation in sample preparation, and applications of mathematical and computational models for optimisation of different protocols were observed, and pre-analyses included various derivatisation techniques, and environmentally friendly extraction protocols. CONCLUSIONS: GC-based analysis of naturally occurring cannabinoids, especially using GC-MS, has dominated the cannabinoids analysis in the last decade; new derivatisation methods, new ionisation methods, and mathematical models for method optimisation have been introduced.
- Klíčová slova
- Cannabis sativa, GC-FID, GC-MS, analysis, cannabinoids, cannabis, detection, gas chromatography (GC), marijuana,
- MeSH
- Cannabis * MeSH
- kanabinoidy * MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
- tandemová hmotnostní spektrometrie MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- kanabinoidy * MeSH