Among different substance classes, New Psychoactive Substances (NPS) comprise chiral amphetamines for stimulant and empathic effects. There is little knowledge in terms of clinical studies about possibly different effects of the two enantiomers of novel amphetamine derivatives. For this reason, there is a big demand for enantioseparation method development of this new substance class. Regarding gas chromatography, cyclodextrins proved to be effective for enantioseparation of NPS. In our attempt, an Astec® ChiraldexTM G-PN column containing 2,6-di-O-pentyl-3-propionyl-γ-cyclodextrin and a LipodexTM D column containing heptakis-(2,6-di-O-pentyl-O-acetyl)-β-cyclodextrin as chiral selector served as stationary phases in a Shimadzu GCMS-QP2010 SE system. Because of the special coating, maximum temperature is limited to 200 °C isothermal or 220 °C in programmed mode. To ensure detection, trifluoroacetic anhydride (TFAA) was used to increase sample volatility.1 As a result, 35 amphetamines were tested as their TFAA-derivatives. A screening method with a temperature gradient from 140 °C to 200 °C at a heating ramp of 1 °C per minute and final time of 5 min, showed baseline separation for seven and partial separations for 16 trifluoro acetylated amphetamines using the ChiraldexTM G-PN column. Six baseline and nine partial separations were observed with the LipodexTM D column, respectively.
Blood is a complex biological matrix providing valuable information on nutritional, metabolic, and immune status. The detection of blood biomarkers requires sensitive analytical methods because analytes are at very low concentrations. Peripheral blood monocytes play a crucial role in inflammatory processes, and the metabolites released by monocytes during these processes might serve as important signalling molecules and biomarkers of particular physiological states. Headspace solid-phase microextraction (HS-SPME) combined with two different mass spectrometric platforms, two-dimensional (2D) gas chromatography coupled to time-of-flight mass spectrometry (2D-GC/TOF-MS) and one-dimensional gas chromatography coupled to Orbitrap mass spectrometry (GC/Orbitrap-MS), were applied for the investigation of volatile organic compounds (VOCs) produced by human peripheral blood monocytes. An optimized method was subsequently applied for the characterization of changes in VOCs induced by lipopolysaccharides (LPS) and zymosan (ZYM) stimulation. Overall, the 2D-GC/TOF-MS and the 1D-GC/Orbitrap-MS analyses each yielded about 4000 and 400 peaks per sample, respectively. In total, 91 VOCs belonging to eight different chemical classes were identified. The samples were collected in two fractions, conditioned media for monitoring extracellularly secreted molecules and cell pellet samples to determine the intracellular composition of VOCs. Alcohols, ketones, and hydrocarbons were the main chemical classes of the metabolic profile identified in cell fractions. Aldehydes, acids and cyclic compounds were characteristic of the conditioned media fraction. Here we demonstrate that HS-SPME-2D-GC/TOF-MS is more suitable for the identification of specific VOC profiles produced by human monocytes than 1D-GC/Orbitrap-MS. We define the signature of VOCs occurring early after monocyte activation and characterise the signalling compounds released by immune cells into media.
- MeSH
- lidé MeSH
- mikroextrakce na pevné fázi MeSH
- monocyty metabolismus MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí metody MeSH
- reprodukovatelnost výsledků MeSH
- těkavé organické sloučeniny * analýza izolace a purifikace metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Bile acids are a group of compounds essential for lipid digestion and absorption with a steroid skeleton and a carboxylate side chain usually conjugated to glycine or taurine. Bile acids are regulatory molecules for a number of metabolic processes and can be used as biomarkers of various disorders. Since the middle of the twentieth century, the detection of bile acids has evolved from simple qualitative analysis to accurate quantification in complicated mixtures. Advanced methods are required to characterize and quantify individual bile acids in these mixtures. This article overviews the literature from the last two decades (2000-2020) and focuses on bile acid analysis in various human biological samples. The methods for sample preparation, including the sample treatment of conventional (blood plasma, blood serum, and urine) and unconventional samples (bile, saliva, duodenal/gastric juice, feces, etc.) are shortly discussed. Eventually, the focus is on novel analytical approaches and methods for each particular biological sample, providing an overview of the microcolumn separation techniques, such as high-performance liquid chromatography, gas chromatography, and capillary electrophoresis, used in their analysis. This is followed by a discussion on selected clinical applications.
- MeSH
- lidé MeSH
- mikrotechnologie MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí metody MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- žlučové kyseliny a soli analýza chemie metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
In this study, a GC-MS method was developed for the quantification of saccharides in complex mixtures such as bio-oils and bio-oil aqueous phases produced by ablative pyrolysis of lignocellulosic biomass. The samples were first treated using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and the trimethylsilylated (more volatile) derivatives were analyzed by GC-MS. The method offers advantages of great separation capability and simultaneous identification of unknown peaks by comparison of the mass spectra and retention indices with extensive libraries available online. However, even with these tools at hand, the identification of several saccharide-resembling compounds can be challenging especially in such highly complex samples as pyrolysis bio-oils. For this reason, we devised a novel procedure, which eliminates certain saccharides depending on their specific chemical properties before subjecting the samples to the GC-MS analysis. The procedure was based on the combination of aniline treatment (elimination of reducing aldoses), and hydrolysis (elimination of anhydrosugars, glycosides, disaccharides and oligosaccharides). Based on the differences in chromatograms before and after the procedure, the unknown compounds were assigned into groups based on their susceptibility to each treatment. The combination of all methods above has allowed more accurate identification and quantification of saccharides, some of which were not as of today found in bio-oils.
L-amino acids (L-AAs) play different important roles in the physiology of all living organisms. Their chiral counterparts, D-amino acids (D-AAs) are increasingly being recognized as essential molecules in many biological systems. Secondary amino acids with cyclic structures, such as prolines, exhibit conformational rigidity and thus unique properties in the structural and protein folding. Despite their widespread occurrence, much less attention was paid to their chiral analysis, particularly when the minor, typically D-enantiomer, is present in low amounts in a complex biological matrix. In this paper, a cost-effective, chiral GC-MS method is described for capillary Chirasil-L-Val separation of nine cyclic secondary amino acid enantiomers with four-, five-, and six-membered rings, involving azetidine-2-carboxylic acid, pipecolic acid, nipecotic acid, proline, isomeric cis/trans 3-hydroxy, 4-hydroxyproline, and cis/trans-5-hydroxy-L-pipecolic acid in the excess of its enantiomeric antipode. The sample preparation involves in-situ derivatization with heptafluorobutyl chloroformate, simultaneous liquid-liquid micro-extraction into isooctane followed by amidation of the arising low-polar derivatives with methylamine, an evaporation step, re-dissolution, and final GC-MS analysis. The developed method was used for analyses of human biofluids, biologically active peptides containing chiral proline constituents, and collagen.
- MeSH
- fluorokarbony chemie MeSH
- formiáty chemie MeSH
- iminokyseliny analýza chemie MeSH
- kalibrace MeSH
- lidé MeSH
- methylaminy chemie MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí metody normy MeSH
- reprodukovatelnost výsledků MeSH
- stereoizomerie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- balneologie metody trendy MeSH
- duševní poruchy * metabolismus rehabilitace MeSH
- hydrokortison krev metabolismus MeSH
- kortikosteron krev metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- limbický systém metabolismus MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí metody MeSH
- pregnenolon krev metabolismus MeSH
- sebeposuzující dotazníky PHQ MeSH
- serotonin krev metabolismus MeSH
- techniky cvičení a pohybu MeSH
- terapie cvičením MeSH
- tryptofan krev metabolismus MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- práce podpořená grantem MeSH
Gas chromatography (GC) is a commonly used technique in amino acid analysis (AAA). However, one of the requirements of the application of GC for AAA is a need for the polar analytes to be converted into their volatile, thermally stable derivatives. In the last two decades, alkyl chloroformates (RCFs) have become attractive derivatization reagents. The reagents react immediately with most amino acid functional groups in aqueous matrices, and the process can easily be coupled with liquid-liquid extraction of the resulting less polar derivatives into immiscible organic phase. Here we describe a simple protocol for in situ derivatization of amino acids with heptafluorobutyl chloroformate (HFBCF) followed by subsequent chiral as well as nonchiral GC/MS (mass spectrometric) analysis on a respective nonpolar fused silica and an enantioselective Chirasil-Val capillary column.
- MeSH
- aminokyseliny krev chemie izolace a purifikace MeSH
- deuterium analýza chemie MeSH
- extrakce kapalina-kapalina přístrojové vybavení metody MeSH
- fluorokarbony chemie MeSH
- formiáty chemie MeSH
- izotopy uhlíku analýza chemie MeSH
- kalibrace MeSH
- lidé MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí přístrojové vybavení metody MeSH
- stereoizomerie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Resveratrol (3,5,4'-trihydroxystilbene) is one of the most abundant polyphenols in red grapes, and red wine represents one of the most important dietary sources of this compound. Although its beneficial properties on human health have been widely investigated over the last 30 years, very little is known about its derivatives. Resveratrol can indeed undergo glycosylation, oligomerization and, upon UV-light exposure, it can isomerize from the trans-to the cis-isomer, which can further cyclize to 2,4,6-trihydroxyphenanthrene (THP). Although the effects of THP on human health are not yet known, being a polycyclic aromatic hydrocarbon, it can be potentially harmful. Because no data about THP occurrence in plant food and beverages are available, a simple procedure based on liquid-liquid extraction and gas chromatography-mass spectrometry has been developed and validated for the simultaneous qualitative and quantitative analysis of trans-resveratrol, cis-resveratrol, and THP in red wine, before and after UV-light exposure.
CONTEXT: Improvement of imaging methods has led to more incidental adrenal tumor findings, especially adenomas. Routine hormonal evaluation uses only a few steroids to evaluate possible hormonal hypersecretion of these adenomas, but a wide spectrum of serum steroid hormone changes has not been published. OBJECTIVE: To measure the serum levels of 83 steroids from patients with unilateral and bilateral adrenal incidentalomas to uncover full steroid profile changes in patients with subclinical hypercortisolism (SH). DESIGN: Cross-sectional study. SETTING: The study was conducted at a tertiary inpatient clinic. PATIENTS: Fifty-two patients with adrenal incidentalomas (unilateral, n = 29; bilateral, n = 23), including nonfunctioning (n = 11) vs SH (n = 41), and 26 age- and sex-matched controls from the general population were included. MAIN OUTCOME MEASURES: Eighty-three serum steroids were measured by gas chromatography-tandem mass spectrometry (GC-MS/MS) before and after 1 mg dexamethasone, ACTH, midnight serum cortisol, and urinary free cortisol/24 hour. RESULTS: Of 83 measured steroids, 10 were significantly decreased in patients with SH, including dehydroepiandrosterone sulfate (DHEAS), androsterone sulfate, epiandrosterone sulfate, androstenediol sulfate, conjugated 5α-androstane-3β,17β-diol, and conjugated 5α-androstane-3α,17β-diol. This finding was observed even when unilateral, bilateral, male, and female subgroups were analyzed separately. When we compared routine clinical methods and GC-MS/MS‒measured steroids, the most discriminatory was DHEAS followed by midnight serum cortisol, epiandrosterone sulfate, androsterone sulfate, ACTH, and 16α-hydroxypregnenolone. CONCLUSIONS: SH was associated with decreased levels of adrenal androgens, their metabolites, and pregnenolone metabolite. GC-MS/MS is a powerful tool for measuring serum levels of these undescribed changes in steroid metabolism, which are characteristic of SH in adrenal incidentalomas.
- MeSH
- adrenokortikální hyperfunkce komplikace diagnóza MeSH
- lidé středního věku MeSH
- lidé MeSH
- nádory nadledvin krev etiologie MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí metody MeSH
- průřezové studie MeSH
- steroidy krev MeSH
- tandemová hmotnostní spektrometrie metody MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Urea, as an end product of protein metabolism and an abundant polar compound, significantly complicates the metabolomic analysis of urine by GC-MS. We developed a sample preparation method removing urea from urine samples prior the GC-MS analysis. The method based on urease immobilized on magnetic microparticles was compared with the others that are conventionally used (liquid-liquid extraction, free urease protocol), and samples without any treatment. To study the impact of sample preparation approaches on the quality of analytical data, we employed comprehensive metabolomic analysis (using both GC-MS and LC-MS/MS platforms) of standard material based on human urine. Multivariate statistical analysis has shown that immobilized urease treatment provides similar results to a free urease approach. However, significant alterations in the profiles of metabolites were observed in the samples without any treatment and after the extraction. Compared to other approaches that were tested, the immobilization of urease on microparticles reduces both the number of artifacts and the variability of the metabolites (average CV of extraction 19.7%, no treatment 11.4%, free urease 5.0%, and immobilized urease 2.5%). The method that was developed was applied in a GC-MS metabolomic experiment of glutaric aciduria type I, where both known diagnostically important biomarkers and unknowns, as the most discriminating compounds, were found.
- MeSH
- analýza hlavních komponent MeSH
- chromatografie kapalinová metody MeSH
- enzymy imobilizované moč MeSH
- glutaryl-CoA-dehydrogenasa nedostatek metabolismus MeSH
- lidé MeSH
- magnetické jevy * MeSH
- metabolické nemoci mozku metabolismus MeSH
- metabolom MeSH
- metabolomika metody MeSH
- metody pro přípravu analytických vzorků * MeSH
- močovina metabolismus MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí metody MeSH
- reprodukovatelnost výsledků MeSH
- studie proveditelnosti MeSH
- tandemová hmotnostní spektrometrie MeSH
- ureasa moč MeSH
- vrozené poruchy metabolismu aminokyselin metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
