Concentration level, health risk assessment and source apportionment of nitrosamines in PM2.5 in Urumqi during winter time

Wang, Juanmei; Zhou, Xiaolong; Hua, Zhenyu; Jiang, Na; He, Xintong

doi:10.1016/j.apr.2023.101756

Cited by 6 publications

(2 citation statements)

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“…The results show that 1 h after emission, the mixing ratios of PIP-NO and PIP-NO 2 will be around 10, respectively 5 times larger than those of nitrosodimethylamine (NDMA) and dimethylnitramine (DMNM) per unit of amine emitted, respectively, as shown in Figure S21. Although the actinic flux and NOx-conditions in London, Seoul, and Urumqi differ substantially from those characteristic of Oslo, it is obvious that the major part of nitrosamines reported in the atmospheric particulate matter in central London, 8 Seoul, 9,10 and in Urumqi, 11 cannot originate in gas phase photo-oxidation of the corresponding amines.…”

Section: Discussionmentioning

confidence: 83%

“…The corresponding nitrosamine, 1-nitrosopiperidine (PIP-NO), was reported in the atmospheric particulate matter (PM 2.5 ) in central London 8 and later in PM 2.5 and PM 10 samples 9 , 10 collected at Seoul, Korea, and recently in PM 2.5 samples collected at Urumqi, China. 11 A comprehensive examination of nitrosamines in a Korean water system, including sewage treatment plants, river water, and seawater reported PIP-NO concentrations of ∼100 ng L –1 in the sewage treatment plants influent and ∼5 ng L –1 in the effluent, whereas the concentrations in the river water and seawater was reported to be <1 and ∼2 ng L –1 , respectively. 12 More recently, PIP-NO was reported with an average of 22 ng L –1 in 4 of 5 drinking water samples collected from 13 cities in the state of São Paulo, Brazil, 13 and in 47 of 117 samples of treated water throughout China (average 2.9 ng L –1 ).…”

Section: Introductionmentioning

confidence: 99%

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Experimental and Theoretical Study of the OH-Initiated Degradation of Piperidine under Simulated Atmospheric Conditions

Tan,

Zhu,

Mikoviny

et al. 2024

J. Phys. Chem. A

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The OH-initiated photo-oxidation of piperidine and the photolysis of 1-nitrosopiperidine were investigated in a large atmospheric simulation chamber and in theoretical calculations based on CCSD(T*)-F12a/aug-cc-pVTZ//M062X/ aug-cc-pVTZ quantum chemistry results and master equation modeling of the pivotal reaction steps. The rate coefficient for the reaction of piperidine with OH radicals was determined by the relative rate method to be k OH-piperidine = (1.19 ± 0.27) × 10 −10 cm 3 molecule −1 s −1 at 304 ± 2 K and 1014 ± 2 hPa. Product studies show the piperidine + OH reaction to proceed via H-abstraction from both CH 2 and NH groups, resulting in the formation of the corresponding imine (2,3,4,5tetrahydropyridine) as the major product and in the nitramine (1-nitropiperidine) and nitrosamine (1-nitrosopiperidine) as minor products. Analysis of 1-nitrosopiperidine photolysis experiments under natural sunlight conditions gave the relative rates j rel = j 1-nitrosoperidine /j NOd 2 = 0.342 ± 0.007, k 3 /k 4a = 0.53 ± 0.05 and k 2 / k 4a = (7.66 ± 0.18) × 10 −8 that were subsequently employed in modeling the piperidine photo-oxidation experiments, from which the initial branchings between H-abstraction from the NH and CH 2 groups, k N−H /k tot = 0.38 ± 0.08 and k C 2 −H /k tot = 0.49 ± 0.19, were derived. All photo-oxidation experiments were accompanied by particle formation that was initiated by the acid−base reaction of piperidine with nitric acid. Primary photo-oxidation products including both 1-nitrosopiperidine and 1-nitropiperidine were detected in the particles formed. Quantum chemistry calculations on the OH initiated atmospheric photo-oxidation of piperidine suggest the branching in the initial H-abstraction routes to be ∼35% N 1 , ∼50% C 2 , ∼13% C 3 , and ∼2% C 4 . The theoretical study produced an atmospheric photo-oxidation mechanism, according to which H-abstraction from the C 2 position predominantly leads to 2,3,4,5-tetrahydropyridine and H-abstraction from the C 3 position results in ring opening followed by a complex autoxidation, of which the first few steps are mapped in detail. H-abstraction from the C 4 position is shown to result mainly in the formation of piperidin-4-one and 2,3,4,5-tetrahydropyridin-4-ol, whereas H-abstraction from N 1 under atmospheric conditions primarily leads to 2,3,4,5-tetrahydropyridine and in minor amounts of 1-nitrosopiperidine and 1-nitropiperidine. The calculated rate coefficient for the piperidine + OH reaction agrees with the experimental value within 35%, and aligning the theoretical numbers to the experimental value results in k(T) = 2.46 × 10 −12 × exp(486 K/T) cm 3 molecule −1 s −1 (200−400 K).

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