The concentrations of semivolatile organic compounds, organochlorine pesticides and heavy metals in sediments from Jiangsu reach of Huaihe River, China, were presented. The organic compounds were extracted by acetone...The concentrations of semivolatile organic compounds, organochlorine pesticides and heavy metals in sediments from Jiangsu reach of Huaihe River, China, were presented. The organic compounds were extracted by acetone： n-hexane using a Soxhlet apparatus and concentrations were performed using HP6890 gas chromatography coupled by FID and ECD detector. The total contents of 8 heavy metals by inductively coupled plasma atomic emission spectrometry or cold-vapor/atomic absorption spectrometry were developed. 30 semivolatile organic compounds were detected, including substituted benzenes, phenols, phthalates and polycyclic aromatic hydrocarbons, from 0.01 to 3.01 mg/kg. 16 organochlorine pesticides were almost detected and from 0.010 to 2.339 μg/kg. Concentrations of major metals were 50 mg/kg or less, mean level of mercury was only 0.055 mg/kg. Compared to sediment quality guidelines （SQGs）, concentrations of some semivolatilc organic compounds were high enough to cause possible toxic effects to living resources. The organochlorine pesticides presented relatively low, lower than threshold effect concentrations （TECs）, harmful effects on sediment-dwelling organisms were not expected. Chromium posed probable toxic effects to the living resources, other heavy metals had no threat temporarily according to SQGs.展开更多
Supercritical carbon dioxide fluid extraction (SFE) was studied as a rapid method for extraction of volatile and semivolatile compounds of Chinese commercial cigarettes. The method was compared with simultaneous disti...Supercritical carbon dioxide fluid extraction (SFE) was studied as a rapid method for extraction of volatile and semivolatile compounds of Chinese commercial cigarettes. The method was compared with simultaneous distillation and extraction (SDE). Temperature and pressure for the SFE were optimized. The extracts obtained by the two methods showed different characters in composition and represented differently the flavor characteristics of tobacco; compared to SDE, SFE can extract compounds within a shorter time and avoid the thermal degradation and solvent contamination of samples. The extracts by the two extraction methods are complementary for investigating the flavor characteristic of tobacco products.展开更多
Secondary organic aerosol(SOA)is a very important component of fine particulate matter(PM)in the atmosphere.However,the simulations of SOA,which could help to elucidate the detailed mechanism of SOA formation and quan...Secondary organic aerosol(SOA)is a very important component of fine particulate matter(PM)in the atmosphere.However,the simulations of SOA,which could help to elucidate the detailed mechanism of SOA formation and quantify the roles of various precursors,remains unsatisfactory,as SOA levels are frequently underestimated.It has been found that the performance of SOA formation models can be significantly improved by incorporating the emission and evolution of semivolatile and intermediate-volatility organic compounds(S/IVOCs).In order to explore the roles of S/IVOCs in SOA formation,this study reviews some simulation models which could consider S/IVOCs for SOA formation as well as the development of emission inventories of S/IVOCs and S/IVOC modules for SOA formation.In addition,the future research directions for simulations of the effect of S/IVOCs on SOA formation are suggested.展开更多
文摘The concentrations of semivolatile organic compounds, organochlorine pesticides and heavy metals in sediments from Jiangsu reach of Huaihe River, China, were presented. The organic compounds were extracted by acetone： n-hexane using a Soxhlet apparatus and concentrations were performed using HP6890 gas chromatography coupled by FID and ECD detector. The total contents of 8 heavy metals by inductively coupled plasma atomic emission spectrometry or cold-vapor/atomic absorption spectrometry were developed. 30 semivolatile organic compounds were detected, including substituted benzenes, phenols, phthalates and polycyclic aromatic hydrocarbons, from 0.01 to 3.01 mg/kg. 16 organochlorine pesticides were almost detected and from 0.010 to 2.339 μg/kg. Concentrations of major metals were 50 mg/kg or less, mean level of mercury was only 0.055 mg/kg. Compared to sediment quality guidelines （SQGs）, concentrations of some semivolatilc organic compounds were high enough to cause possible toxic effects to living resources. The organochlorine pesticides presented relatively low, lower than threshold effect concentrations （TECs）, harmful effects on sediment-dwelling organisms were not expected. Chromium posed probable toxic effects to the living resources, other heavy metals had no threat temporarily according to SQGs.
文摘Supercritical carbon dioxide fluid extraction (SFE) was studied as a rapid method for extraction of volatile and semivolatile compounds of Chinese commercial cigarettes. The method was compared with simultaneous distillation and extraction (SDE). Temperature and pressure for the SFE were optimized. The extracts obtained by the two methods showed different characters in composition and represented differently the flavor characteristics of tobacco; compared to SDE, SFE can extract compounds within a shorter time and avoid the thermal degradation and solvent contamination of samples. The extracts by the two extraction methods are complementary for investigating the flavor characteristic of tobacco products.
基金supported by the State Key Program of National Natural Science Foundation of China(No.91644215)the National Key Research and Development Program of China(Nos.2017YFC0210106 and 2016YFC0202206)+3 种基金the National Natural Science Foundation of China(No.41775114)the Pearl River Science&Technology Nova Program of Guangzhou(No.201806010146)the Fundamental Research Funds for the Central Universities(No.19lgzd06)the Special Fund Project for Science and Technology Innovation Strategy of Guangdong Province(No.2019B121205004)
文摘Secondary organic aerosol(SOA)is a very important component of fine particulate matter(PM)in the atmosphere.However,the simulations of SOA,which could help to elucidate the detailed mechanism of SOA formation and quantify the roles of various precursors,remains unsatisfactory,as SOA levels are frequently underestimated.It has been found that the performance of SOA formation models can be significantly improved by incorporating the emission and evolution of semivolatile and intermediate-volatility organic compounds(S/IVOCs).In order to explore the roles of S/IVOCs in SOA formation,this study reviews some simulation models which could consider S/IVOCs for SOA formation as well as the development of emission inventories of S/IVOCs and S/IVOC modules for SOA formation.In addition,the future research directions for simulations of the effect of S/IVOCs on SOA formation are suggested.
