Carbon isotopic characterization of formaldehyde emitted by vehicles in Guangzhou, China

Chemical and stable carbon isotopic composition of PM<sub>2.5</sub> from on-road vehicle emissions in the PRD region and implications for vehicle emission control policy

“…Generally, the variation in δ 13 C Fuel could affect the δ 13 C of hydrocarbons (Keppler et al, 2004;Yamada et al, 2009). In the PRD region, the δ 13 C values of gasoline and diesel were on average −28.6 ± 0.6 ‰ and −27.8 ± 0.2 ‰; small variations of fuel δ 13 C were observed (Hu et al, 2014). We calculated the isotopic differences between δ 13 C PM 2.5 and δ 13 C Fuel , which represent the apparent isotopic fractionation occurring during fuel burning.…”

On-road vehicle emissions of glyoxal and methylglyoxal from tunnel tests in urban Guangzhou, China

“…The details of analytical procedures for carbonyl compounds were described by Hu et al (2014). In brief, the sampled cartridges were eluted slowly with 2 mL acetonitrile (ACN, HPLC/GCMS grade; Sigma) into a 2-mL volumetric flask and a 10-mL aliquot was injected into the Agilent Model 1200 high-performance liquid chromatography (HPLC) with an Agilent SBC18 reverse column (250 Â 4.6 mm, 5 mm) and a UV detector (360 nm).…”

“…This rapid growth in vehicle number makes vehicle exhaust an increasingly important contributor to air pollutants including carbonyls Wen et al, 2005;Hu et al, 2014), particularly in the urban areas. To determine vehicle emission factors, road tunnels are excellent locations not only because the influence of meteorological conditions is minimized and the emissions undergo 'real world' dilution effect with minimal interference from other sources, but also because road tunnel tests provide emissions from a large number of vehicles operating at 'real world' hot and stable conditions when going through a road tunnel.…”