A new time-integrated thermal desorption technique has been developed that can be used with selected ion flow tube mass spectrometry, TI-TD/SIFT-MS, for off-line quantitative analyses of VOCs accumulated onto sorbents. Using a slow desorption temperature ramp, the absolute amounts of desorbed compounds can be quantified in real time by SIFT-MS and constitutional isomers can be separated. To facilitate application of this technique to environmental atmospheric monitoring, method parameters were optimised for quantification of the three common atmospheric monoterpenes: β-pinene, R-limonene and 3-carene. Three sorbent types, Tenax TA, Tenax GR and Porapak Q, were tested under 26 different desorption conditions determined by the "design of experiment", DOE, systematic approach. The optimal combination of type of sorbent, bed length, sampling flow rate, sample volume and the initial desorption temperature was determined from the experimental results by ANOVA. It was found that Porapak Q exhibited better efficiency of sample collection and further extraction for total monoterpene concentration measurements. On the other hand, Tenax GR or TA enabled separation of all three monoterpenes. The results of this laboratory study were tested with the sample accumulated from a branch of a Pinus nigra tree. Graphical abstract.
- Publikační typ
- časopisecké články MeSH
The objective of this experimental study was to discover volatile metabolites present in exhaled breath that could be used as biomarkers of gastro-esophageal reflux disease, GERD, one of the most common causes of chronic cough. An in vitro model based on pork tissue samples exposed to a challenge by artificial gastric fluid was used to identify specific volatile compounds to be chosen for quantification in directly exhaled breath of GERD patients and controls using selected ion flow tube mass spectrometry, SIFT-MS. GC/MS analyses of the headspace of this in vitro model indicated that the only volatile compound significantly increased was acetic acid. End expiratory concentration of acetic acid measured by SIFT-MS in mouth exhaled breath of 22 GERD patients (median 85 ppbv) was found to be significantly higher than that in breath of a control group (median 48 ppbv). Breath acetic acid may be useful for non-invasive diagnostics of GERD and other conditions resulting in the lowering of pH of the lining of the airways.
- MeSH
- aceton analýza MeSH
- časové faktory MeSH
- dechové testy metody MeSH
- dítě MeSH
- dospělí MeSH
- gastroezofageální reflux diagnóza metabolismus MeSH
- ionty MeSH
- kyselina octová analýza MeSH
- lidé středního věku MeSH
- lidé MeSH
- maso MeSH
- mladiství MeSH
- mladý dospělý MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
- prasata MeSH
- předškolní dítě MeSH
- ROC křivka MeSH
- senioři MeSH
- volatilizace MeSH
- vydechnutí * MeSH
- zvířata MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- senioři MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
