Exhaled aliphatic aldehydes were proposed as non-invasive biomarkers to detect increased lipid peroxidation in various diseases. As a prelude to clinical application of the multicapillary column–ion mobility spectrometry for the evaluation of aldehyde exhalation, we, therefore: (1) identified the most abundant volatile aliphatic aldehydes originating from in vitro oxidation of various polyunsaturated fatty acids; (2) evaluated emittance of aldehydes from plastic parts of the breathing circuit; (3) conducted a pilot study for in vivo quantification of exhaled aldehydes in mechanically ventilated patients. Pentanal, hexanal, heptanal, and nonanal were quantifiable in the headspace of oxidizing polyunsaturated fatty acids, with pentanal and hexanal predominating. Plastic parts of the breathing circuit emitted hexanal, octanal, nonanal, and decanal, whereby nonanal and decanal were ubiquitous and pentanal or heptanal not being detected. Only pentanal was quantifiable in breath of mechanically ventilated surgical patients with a mean exhaled concentration of 13 ± 5 ppb. An explorative analysis suggested that pentanal exhalation is associated with mechanical power—a measure for the invasiveness of mechanical ventilation. In conclusion, exhaled pentanal is a promising non-invasive biomarker for lipid peroxidation inducing pathologies, and should be evaluated in future clinical studies, particularly for detection of lung injury. 相似文献
A stainless steel fiber was coated with a gate-opening controlled metal-organic framework ZIF-7 via a sol-gel method and applied to the solid-phase microextraction of aldehydes (hexanal, heptanal, octanal, nonanal, decanal) from exhaled breath by lung cancer patients. The effects of temperature and time on the sorption and desorption were optimized. Under optimum condition, the modified fiber displays enrichment factors (typically ranging from 300 to 10,000), low limits of detection (0.61–0.84 μg L?1), and wide linear ranges of hexanal, heptanal (5–500 μg L?1) and octanal, nonanal, decanal (10–1000 μg L?1). The high extraction capability for aldehydes is thought to result from (a) the combined effects of the large surface area and the unique porous structure of the ZIF-7, (b) the hydrophobicity and gate-opening effect of the sorbent, (c) the high selectivity of the window, and (d) the presence of unsaturated metal-coordination sites. The coated fiber is thermally stable and can be re-used >150 times. The relative standard deviation (RSD) for six replicate extractions using a single fiber ranged from 1.4–15.3% for intra-day and 2.4–16.1% for inter-day. The fiber-to-fiber reproducibility for three fibers prepared in parallel was in the range of 2.4–12.6% (RSD). The method was applied to the extraction of aldehydes from real samples and to the quantitation by gas chromatography. Recoveries from spiked samples ranged from 84 to 113%.
Graphical abstract A metal-organic framework ZIF-7 coated stainless steel fiber was prepared via sol-gel method. The self-made fiber was applied in the solid phase microextraction of aldehydes from exhaled breath of lung cancer patients.
We describe a simple derivatization method to determine aldehydes. This method is based on derivatization with D-cysteine and consecutive liquid chromatography-tandem mass spectrometry (LC-MS/MS). The optimum derivatization conditions of aldehydes with D-cysteine were 10 min at 50°C and pH 7.0. The formed alkyl thiazolidine-4-carboxylic acid derivatives were directly injected in LC-MS/MS. In the established condition, the method was used to detect eight aldehydes in beverages. The limit of detection (LOD) and limit of quantification (LOQ) of the aldehydes were 0.2-1.9 μg L(-1) and 0.7-6.0 μg L(-1) and the relative standard deviation was less than 2.0% at concentrations of 0.1 mg L(-1) and 1.0 mg L(-1) with the exception of octanal. All the beverage samples had detectable levels of methanal (0.033-0.145 mg L(-1)), ethanal (0.085-2.12 mg L(-1)), propanal (ND to 0.250 mg L(-1)), butanal (ND to 0.003 mg L(-1)), pentanal (ND to 0.471 mg L(-1)), hexanal (ND to 0.805 mg L(-1)), heptanal (0.019-3.91 mg L(-1)) and octanal (0.029-0.118 mg L(-1)). 相似文献
Peanut oil is favored by consumers due to its rich nutritional value and unique flavor. This study used headspace solid-phase microextraction (HS-SPME) combined with gas chromatography (GC) and gas chromatography–mass spectrometry (GC-MS) to examine the differences in the peanut oil aroma on the basis of variety, roasting temperatures, and pressing components. The results revealed that the optimal conditions for extracting peanut oil were achieved through the use of 50/30 μm DVB/CAR/PDMS fibers at 60 °C for 50 min. The primary compounds present in peanut oil were pyrazines. When peanuts were roasted, the temperature raised from 120 °C to 140 °C and the content of aldehydes in peanut oil increased; however, the content of aldehydes in No. 9 oil at 160 °C decreased. The components of peanut shell oil varied depending on the peanut variety. The most marked difference was observed in terms of the main compound at the two roasting temperatures. This compound was a pyrazine, and the content increased with the roasting temperature in hekei oils. When the roasting temperature was lower, No. 9 oil contained more fatty acid oxidation products such as hexanal, heptanal, and nonanal. When the roasting temperature increased, No. 9 oil contained more furfural and 5-methylfurfural. Heren oil was easier to oxidize and produced nonanal that possessed a fatty aroma. 相似文献
A new technique, headspace single-drop microextraction (HS-SDME) with in-drop derivatization, was developed. Its feasibility was demonstrated by analysis of the model compounds, aldehydes in water. A hanging microliter drop of solvent containing the derivatization agent of O-2,3,4,5,6-(pentaflurobenzyl)hydroxylamine hydrochloride (PFBHA) was shown to be an excellent extraction, concentration, and derivatization medium for headspace analysis of aldehydes by GC-MS. Using the microdrop solvent with PFBHA, acetaldehyde, propanal, butanal, hexanal, and heptanal in water were headspace extracted and simultaneously derivatized. The formed oximes in the microdrop were analyzed by GC-MS. HS-SDME and in-drop derivatization parameters (extraction solvent, extraction temperature, extraction time, stirring rate microdrop volume, and the headspace volume) and the method validations (linearity, precision, detection limit, and recovery) were studied. Compared to liquid-liquid extraction and solid-phase microextraction, HS-SDME with in-drop derivatization is a simple, rapid, convenient, and inexpensive sample technique. 相似文献
A simple, fast, sensitive and cost-effective method based on headspace solid-phase microextraction (HS-SPME) with on-fiber derivatization coupled with gas chromatography-mass spectrometry was developed for the determination of six typical aldehydes, 2E-hexenal, heptanal, 2E-heptenal, 2E,4E-heptadienal, 2E-decenal and 2E,4E-decadienal in laboratory algae cultures. As derivatization reagent, O-2,3,4,5,6-(pentafluorobenzyl) hydroxylamine hydrochloride, was loaded onto the poly(dimethylsiloxane)/divinylbenzene fiber for aldehydes on-fiber derivatization prior to HS-SPME. Various influence factors of extraction efficiency were systematically investigated. Under optimized extraction conditions, excellent method performances for all the six aldehydes were attained, such as satisfactory extraction recoveries ranging from 67.1 to 117%, with the precision (relative standard deviation) within 5.3-11.1%, and low detection limits in the range of 0.026-0.044 μg/L. The validated method was successfully applied for the analysis of the aldehydes in two diatoms (Skeletonema costatum and Chaetoceros muelleri), two pyrrophytas (Prorocentrum micans and Scrippsiella trochoidea) and Calanus sinicus eggs (feeding on the two diatoms above). 相似文献
The volatile compounds of wild gilthead sea bream (Sparus aurata) were analyzed by sensory and instrumental analyses. Simultaneous distillation and extraction (SDE) with dichloromethane were used for extraction of volatile components. According to sensory analysis, the aromatic extract obtained by SDE was representative of sea bream odour. A total of 46 compounds were identified and quantified in sea bream. Aldehydes and alcohols were the most dominant volatiles in sea bream, as they accounted for the largest proportion. Hexanal, heptanal, nonanal, (Z)-4-heptenal, octanal, (E)-2-nonenal, decanal, benzenacetaldehyde, (E,E)-2,4-decadienal, 1-octen-3-ol and (E)-1,5-octadien-3-ol were potent aroma compounds on the basis of odour activity values (OAVs). Within these, decanal (OAV: 1110) and (E)-2-nonenal (OAV: 447.5) were the most powerful contributors to the aroma of the sea bream. 相似文献
