Polycyclic aromatic hydrocarbons （EPA-PAHs） in the urban surface soils from Beijing were determined using gas chromatography and mass spectrometry （GC-MS）. It is significantly complementary for understanding the P...Polycyclic aromatic hydrocarbons （EPA-PAHs） in the urban surface soils from Beijing were determined using gas chromatography and mass spectrometry （GC-MS）. It is significantly complementary for understanding the PAHs pollution in soil of integrated Beijing city on the basis of the information known in the outskirts. The total concentration of 16 EPA-PAH was from 0.467 to 5.470 μg/g and was described by the contour map. Compound profiles presented that the 4-, 5- and 6-ring PAHs were major compositions. The correlation analysis showed that PAHs have the similar source in the most sampling sites and BaP might be considered as the indicator of PAHs. Characteristic ratios of anthracene （An）/（An＋ phenanthrene （Phe））, fluoranthene （Flu）/（Flu/ pyrene （Pyr）） and benzo[a]pyrene （BaP）/laenzo[g,h,i]perylene （BghiP） indicated that the PAHs pollutants probably mainly originated from the coal combustion and it was not negligible from vehicular emission. The level of PAHs in our study area was compared with other studies.展开更多
The concentration of organochlorine pesticides（OCPs） in tissues and organs of silver carp（Hypophthalmichthys mofitrix） from Guanting Reservoir were investigated to evaluate the pollution potential and distribution...The concentration of organochlorine pesticides（OCPs） in tissues and organs of silver carp（Hypophthalmichthys mofitrix） from Guanting Reservoir were investigated to evaluate the pollution potential and distribution of OCPs. A total of 16 OCPs were measured and the concentrations were in the range of 1.61-69.01 ng/g wet weight（ww） for total OCPs, 0.16- 0.75 ng/g ww for HCB. 0.75 -26.80 ng/g ww for SHCH（sum of α-,β-, γ- and δ-HCH） and 0.68-35.94 ng/g ww for SDDT（ sum of p, p＇-DDE, p, p＇-DDD, o, p＇-DDT and p, p＇- DDT）. The mean concentrations of total OCPs, HCB, ∑HCH, and ∑DDT were 18.04, 0.96, 7.14 and 9.28 ng/g ww, respectively. Among the organochlorine pesticides, β-HCH and p, p＇-DDE were the most dominant compounds in tissue and organ with the average concentrations of 4.42 and 8.14 ng/g, respectively. The results obtained in this study show that the levels of 16 OCP residues found in silver carps are low and pose no threat to human health and wildlife fed upon them on the basis of existing related quality guidelines. However, recent input of lindane and DDT might still exist in the area investigated and further investigation should be carried on.展开更多
The effects of reactant composition and steam on propane combustion over Pd/LaFe_ 0.8Co_ 0.2O_3 catalyst were investigated. Propane conversion and the oxidation state of palladium were strongly affected by the redox...The effects of reactant composition and steam on propane combustion over Pd/LaFe_ 0.8Co_ 0.2O_3 catalyst were investigated. Propane conversion and the oxidation state of palladium were strongly affected by the redox ratio of reactants. Higher propane conversion could be obtained under rich conditions and explained as a complex balance between oxidation and steam reforming. Water produced in the oxidation could promote the propane conversion by steam reforming. However, the presence of excess steam would bring about inhibition.展开更多
The metabolites of 4 nitrobiphenyl (4 NBP) were studied using S 9 under anaerobic conditions. Dependence of concentrations of metabolites on incubation time and S 9 amounts were followed. Ten metabolites were isol...The metabolites of 4 nitrobiphenyl (4 NBP) were studied using S 9 under anaerobic conditions. Dependence of concentrations of metabolites on incubation time and S 9 amounts were followed. Ten metabolites were isolated and tentatively identified by high performance liquid chromatography/atmospheric pressure chemical ionizaiton/mass spectrometry (HPLC/APCI/MS) and HPLC/UV. Among them, 4 aminobiphenyl and hydroxylaminobiphenyls were found to be the major metabolites, and 4 acetylaminobiphenyl (4 AABP), N hydroxy 4 acetylaminobiphenyl (4 AABP N OH), x OH 4 nitrobiphenyl (4 NBP x OH), biphenylene and N formyl 4 aminobiphenyl (N formyl 4 ABP) were the minor metabolites.展开更多
The assay of trace volatile low molecular weight(MW) compounds in human breath or in ambient atmosphere typically involves gas chromatography with flame ionization detection (FID). This paper introduced a direct assa...The assay of trace volatile low molecular weight(MW) compounds in human breath or in ambient atmosphere typically involves gas chromatography with flame ionization detection (FID). This paper introduced a direct assay which can overcome the difficulties of collection low concentration samples. In order to pre concentrate the trace low MW compounds, a small trapping column filled with absorbent must be used before thermal desorption of the collected samples onto chromatographic column(packed with Porapak Q) for separation. It has been proved that the characteristic of absorbent mainly influence the recoveries and the linear range of this method is from 0 05 ng to 5200 ng for pentane, methanol, ethanol and acetone.展开更多
基金The Major State Basic Research Program of China (No. G1999045707) and the Knowledge Innovation Program of the ChineseAcademy of Sciences (No. RCEES 9902 9906)
文摘Polycyclic aromatic hydrocarbons （EPA-PAHs） in the urban surface soils from Beijing were determined using gas chromatography and mass spectrometry （GC-MS）. It is significantly complementary for understanding the PAHs pollution in soil of integrated Beijing city on the basis of the information known in the outskirts. The total concentration of 16 EPA-PAH was from 0.467 to 5.470 μg/g and was described by the contour map. Compound profiles presented that the 4-, 5- and 6-ring PAHs were major compositions. The correlation analysis showed that PAHs have the similar source in the most sampling sites and BaP might be considered as the indicator of PAHs. Characteristic ratios of anthracene （An）/（An＋ phenanthrene （Phe））, fluoranthene （Flu）/（Flu/ pyrene （Pyr）） and benzo[a]pyrene （BaP）/laenzo[g,h,i]perylene （BghiP） indicated that the PAHs pollutants probably mainly originated from the coal combustion and it was not negligible from vehicular emission. The level of PAHs in our study area was compared with other studies.
基金The Main Basic Research Development Programof China(No. G1999045710) and KIPof CAS(RCEES No.9902)
文摘The concentration of organochlorine pesticides（OCPs） in tissues and organs of silver carp（Hypophthalmichthys mofitrix） from Guanting Reservoir were investigated to evaluate the pollution potential and distribution of OCPs. A total of 16 OCPs were measured and the concentrations were in the range of 1.61-69.01 ng/g wet weight（ww） for total OCPs, 0.16- 0.75 ng/g ww for HCB. 0.75 -26.80 ng/g ww for SHCH（sum of α-,β-, γ- and δ-HCH） and 0.68-35.94 ng/g ww for SDDT（ sum of p, p＇-DDE, p, p＇-DDD, o, p＇-DDT and p, p＇- DDT）. The mean concentrations of total OCPs, HCB, ∑HCH, and ∑DDT were 18.04, 0.96, 7.14 and 9.28 ng/g ww, respectively. Among the organochlorine pesticides, β-HCH and p, p＇-DDE were the most dominant compounds in tissue and organ with the average concentrations of 4.42 and 8.14 ng/g, respectively. The results obtained in this study show that the levels of 16 OCP residues found in silver carps are low and pose no threat to human health and wildlife fed upon them on the basis of existing related quality guidelines. However, recent input of lindane and DDT might still exist in the area investigated and further investigation should be carried on.
文摘The effects of reactant composition and steam on propane combustion over Pd/LaFe_ 0.8Co_ 0.2O_3 catalyst were investigated. Propane conversion and the oxidation state of palladium were strongly affected by the redox ratio of reactants. Higher propane conversion could be obtained under rich conditions and explained as a complex balance between oxidation and steam reforming. Water produced in the oxidation could promote the propane conversion by steam reforming. However, the presence of excess steam would bring about inhibition.
文摘The metabolites of 4 nitrobiphenyl (4 NBP) were studied using S 9 under anaerobic conditions. Dependence of concentrations of metabolites on incubation time and S 9 amounts were followed. Ten metabolites were isolated and tentatively identified by high performance liquid chromatography/atmospheric pressure chemical ionizaiton/mass spectrometry (HPLC/APCI/MS) and HPLC/UV. Among them, 4 aminobiphenyl and hydroxylaminobiphenyls were found to be the major metabolites, and 4 acetylaminobiphenyl (4 AABP), N hydroxy 4 acetylaminobiphenyl (4 AABP N OH), x OH 4 nitrobiphenyl (4 NBP x OH), biphenylene and N formyl 4 aminobiphenyl (N formyl 4 ABP) were the minor metabolites.
文摘The assay of trace volatile low molecular weight(MW) compounds in human breath or in ambient atmosphere typically involves gas chromatography with flame ionization detection (FID). This paper introduced a direct assay which can overcome the difficulties of collection low concentration samples. In order to pre concentrate the trace low MW compounds, a small trapping column filled with absorbent must be used before thermal desorption of the collected samples onto chromatographic column(packed with Porapak Q) for separation. It has been proved that the characteristic of absorbent mainly influence the recoveries and the linear range of this method is from 0 05 ng to 5200 ng for pentane, methanol, ethanol and acetone.
