UV absorption spectra of trans-2-pentenal, trans-2-hexenal and 2-methyl-2-pentenal

Kalalian, Carmen; Samir, Brahim; Roth, E.; Chakir, A.

doi:10.1016/j.cplett.2019.01.028

Cited by 10 publications

(13 citation statements)

References 19 publications

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“…The calculated lifetime of T2P due to its reaction with OH is 7 hours using a 24-h average concentration of 1×10 6 molecules cm -3 for OH (Atkinson et al, 1997) and the average of the rate coefficient values reported in the literature by (Davis et al, 2007) and (Albaladejo et al, 2002) (3.33×10 -11 cm 3 molecule -1 s -1 ). A short lifetime (5 hours) of T2P is calculated for its reaction with NO 3 radicals showing that this process is an important removal pathway for T2P during nighttime (Kalalian et al, 2019). These authors provided a lifetime of 9 days towards reaction with ozone.…”

Section: Atmospheric Implications and Conclusionmentioning

confidence: 99%

An experimental study of the gas-phase reaction between Cl atoms and trans-2-pentenal: Kinetics, products and SOA formation

et al. 2021

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The gas-phase reaction of trans-2-pentenal (T2P) with Cl atoms was studied at atmospheric pressure and room temperature. A rate coefficient of (2.56±0.83)×10 -10 cm 3 molecule -1 s -1 was obtained using the relative rate method and isoprene, cyclohexane and ethanol as reference compounds. The kinetic study was carried out using a 300-L Teflon bag simulation chamber (IMT Lille Douai-France) and a 16-L Pyrex cell (UCLM-Ciudad Real-Spain), both coupled to the Fourier transform infrared (FTIR) technique. Gas-phase products and secondary organic aerosol (SOA) formation were studied at UCLM using a 16-L Pyrex cell and a 264-L quartz simulation chamber coupled to the FTIR and gas-chromatography-mass spectrometry (GC-MS) techniques. HCl, CO, and propanal were identified as products formed from the studied reaction and quantified by FTIR, being the molar yield of the latter (5.2±0.2)%. Formic acid was identified as a secondary product and was quantified by FTIR with a yield of (6.2±0.4)%.In addition, 2-chlorobutanal and 2-pentenoic acid were identified, but not quantified, by GC-MS as products. The SOA formation was investigated using a fast mobility particle sizer spectrometer. The observed SOA yields reached maximum values of around 7% at high particle mass concentrations. This work provides the first study of the formation of gaseous and particulate products for the reaction of Cl with T2P. A reaction mechanism is suggested to explain the formation of the observed gaseous products. The results are discussed in terms of the structure-reactivity relationship, and the atmospheric implications derived from this study are commented as well.

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Section: Atmospheric Implications and Conclusionmentioning

confidence: 99%

An experimental study of the gas-phase reaction between Cl atoms and trans-2-pentenal: Kinetics, products and SOA formation

et al. 2021

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“…In the atmosphere where the atmospheric fate of T2H is mainly governed by its reaction with OH and NO 3 , [24] the impact of SOA formation from T2H ozonolysis is limited. The situation may be reversed indoors where OH and NO 3 radical concentrations are generally much lower than outdoors.…”

Section: Atmospheric Impactmentioning

confidence: 99%

“…Regarding OH + T2H reaction, the three most recent kinetics studies [17][18][19] displayed consistent rate constant values, yielding an average OH rate constant of 4.24×10 -11 cm 3 molecule -1 s -1 at 298 K. NO 3 kinetics was investigated by Atkinson et al [20] who determined a rate constant of 1.21×10 -14 cm 3 molecule -1 s -1 at 298 K. Thus, OH-and NO 3 -initiated reactions represent the main removal of T2H in the atmosphere, with lifetimes of 6h and 8h, respectively, while O 3 reaction may only be competitive in polluted areas where high levels of ozone may be found [24] . Regarding the relevance of T2H atmospheric photolysis, Kalalian et al [24] calculated an upper limit of 29 min assuming a quantum yield of 1, while O'Connor et al [25] and Jiménez et al [18] suggested that T2H photolysis constitutes a negligible pathway compared to its removal through tropospheric oxidants.…”

Section: Introductionmentioning

confidence: 99%

Gas-phase ozonolysis of trans-2-hexenal: Kinetics, products, mechanism and SOA formation

Grira

Kalalian

Illmann

et al. 2021

Atmospheric Environment

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In this work, kinetics, product formation, chemical mechanism and SOA formation for the gas-phase reaction of trans-2-hexenal (T2H) with O 3 are examined using four complementary experimental setups at 298±2 K and atmospheric pressure. Product studies were conducted in two contrasted experimental conditions, with and without OH radical scavenger. The ozonolysis rate constant was determined in both static and dynamic reactors. An average reaction rate constant of (1.52 ± 0.19) × 10 -18 cm 3 molecule -1 s -1 was determined. Glyoxal and butanal were identified as main products with molar yields of 59±15% and 36±9%, respectively, in the presence of an OH scavenger. Slightly lower values were obtained in the absence of scavenger. Acetaldehyde, propanal and 2-hydroxybutanal were also identified and quantified. A reaction mechanism was proposed based on the observed products. SOA formation was observed with aerosol mass yields > 13% for SOA masses of 400 µg m -3 . This work demonstrates for the first time that 2-alkenals ozonolysis can be a source of SOA in the atmosphere.

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“…1.3 × 10 4 M −1 cm −1 , where ε represents molar extinction coefficient), and 310 nm (n→π* absorption, ε = ca. 1.5 × 10 2 M −1 cm −1 ) [67], and total concentrations of the former aldehyde classifications in repeatedly thermo-oxidised CFOs may attain values as high as 50 mmol kg −1 (approximately equivalent to 15 mmol aldehyde/mol FA). Hence, if the total α,β-unsaturated aldehyde concentration in such an oxidised CFO product is 20 mmol kg −1 , then prior to any dilution it will have absorbance values of ca.…”

Section: Spectrophotometric Conjugated Dienes Assaymentioning

confidence: 99%

“…This CDs method is based on the absorption of UV light by conjugated double bonds within CHPD molecules (the conversion of PUFAs to such CHPDs involves a rearrangement of >C=C< double bonds present in these FAs). However, at the wavelength range employed for this relatively simple test (230-235 nm), many interfering compounds also absorb in this spectral region, notably carotenoids, tocopherols and phenolic antioxidants, not to mention possible contributions from α,βunsaturated aldehydes generated from the fragmentation of CHPDs [65,66], especially the more highly unsaturated ones [67]. Indeed, α,β-unsaturated aldehydes and ketones have electronic absorption spectra with maxima located at ca.…”

Section: Spectrophotometric Conjugated Dienes Assaymentioning

confidence: 99%

Commentary: Iconoclastic Reflections on the ‘Safety’ of Polyunsaturated Fatty Acid-Rich Culinary Frying Oils: Some Cautions regarding the Laboratory Analysis and Dietary Ingestion of Lipid Oxidation Product Toxins

et al. 2021

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Continuous or frequent ingestion of fried foods containing cytotoxic/mutagenic/genotoxic lipid oxidation products (LOPs) may present significant human health risks; such toxins are generated in thermally stressed polyunsaturated fatty acid (PUFA)-rich culinary frying oils (CFOs) during standard frying practices. Since monounsaturated and saturated fatty acids (MUFAs and SFAs, respectively) are much less susceptible to peroxidation than PUFAs, in this study CFOs of differential unsaturated fatty acid contents were exposed to laboratory-simulated shallow-frying episodes (LSSFEs). Firstly, we present a case study exploring the time-dependent generation of aldehydic LOPs in CFO products undergoing LSSFEs, which was then used to evaluate the relative potential health risks posed by them, and also to provide suitable recommendations concerning their safety when used for frying purposes. Sunflower, rapeseed, extra-virgin olive and coconut oils underwent LSSFEs at 180 °C: Samples were collected at 0–90 min time-points (n = 6 replicates per oil). Aldehydes therein were determined by high-resolution 1H NMR analysis at 400 and 600 MHz operating frequencies. For one of the first times, CFO LOP analysis was also performed on a non-stationary 60 MHz benchtop NMR spectrometer. 1H NMR analysis confirmed the thermally promoted, time-dependent production of a wide range of aldehydic LOPs in CFOs. As expected, the highest levels of these toxins were produced in PUFA-rich sunflower oil, with lower concentrations formed in MUFA-rich canola and extra-virgin olive oils; in view of its very high SFA content, only very low levels of selected aldehyde classes were generated in coconut oil during LSSFEs. Secondly, 1H NMR results acquired are discussed with regard to the suitability and validity of alternative, albeit routinely employed, spectrophotometric methods for evaluating the peroxidation status of CFOs and lipid-containing foods. Thirdly, an updated mini-review of the toxicological properties of and intake limits for LOPs, and deleterious health effects posed by their ingestion, is provided. In conclusion, exposure of PUFA-rich CFOs to high-temperature frying practices generates very high concentrations of aldehydic LOP toxins from thermally promoted, O2-powered, recycling peroxidation processes; these toxins penetrate into and hence are ‘carried’ by fried foods available for human consumption. Such toxins have the capacity to contribute towards the development and progression of non-communicable chronic diseases (NCDs) if cumulatively ingested by humans.

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UV absorption spectra of trans-2-pentenal, trans-2-hexenal and 2-methyl-2-pentenal

Cited by 10 publications

References 19 publications

An experimental study of the gas-phase reaction between Cl atoms and trans-2-pentenal: Kinetics, products and SOA formation

An experimental study of the gas-phase reaction between Cl atoms and trans-2-pentenal: Kinetics, products and SOA formation

Gas-phase ozonolysis of trans-2-hexenal: Kinetics, products, mechanism and SOA formation

Commentary: Iconoclastic Reflections on the ‘Safety’ of Polyunsaturated Fatty Acid-Rich Culinary Frying Oils: Some Cautions regarding the Laboratory Analysis and Dietary Ingestion of Lipid Oxidation Product Toxins

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