Determination of Hexabromocyclododecane in Expanded Polystyrene and Extruded Polystyrene Foam by Gas Chromatography-Mass Spectrometry.

A gas chromatography-mass spectrometry (GC/MS) method for the determination of hexabromocyclododecane (HBCD) in expanded polystyrene and extruded polystyrene foam (EPS/XPS) was developed. The EPS/XPS samples were ultrasonically extracted with acetone and the extracts were purified by filtration through a microporous membrane (0.22 µm) and solid-phase extraction. The samples were analyzed using a GC/MS using the selected ion monitoring mode. The ions 157, 319 and 401 were selected as the qualitative ions, while ion 239 was chosen as the quantitative ion. An HBCD standard working solution with a concentration range of 1.0-50.0 mg/L showed good linearity. The detection limit of HBCD was 0.5 mg/kg, meeting the LPC limit (<100 or 1000 mg/kg). Six laboratories were selected to verify the accuracy of the method, and 10 samples were tested. The interlaboratory relative standard deviation range was 3.68-9.80%. This method could play an important role in controlling HBCD contamination in EPS/XPS.

A review of levels and profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans in different environmental media from China.

This review provides a summary of the levels and profiles of PCDD/Fs throughout China, as reported in peer reviewed literatures since 1997. The literature shows that PCDD/Fs are widespread in various environmental media including air, water, sediment, and soil. PCDD/Fs concentrations in air were relatively low in most regions, with only a few areas considered polluted. Many studies reported seasonal trends, with higher and lower concentrations in winter and summer, respectively. We analyzed the factors affecting the concentrations of dioxins in air and summarized the causes of seasonal changes. As hydrophobic organic compounds, PCDD/Fs readily accumulate in sediments. The distribution of dioxins in sediment in Bohai Sea area was mainly introduced and the factors affecting concentrations of dioxins were studied. The levels of dioxins in soil in different regions varied greatly, with higher levels in areas close to pollution sources. We examined the dioxins concentrations in soil in places where the levels were very low (including the Tibet Plateau and other remote areas), contaminated areas, and other areas. Apart from the contaminated areas, the dioxins concentrations in soil were low. The results of the relatively low number of studies that have investigated PCDD/Fs in water have reported no obvious pollution in some waters, apart from Dongting Lake. PCDD/Fs levels across China are similar to those worldwide. Point sources, mainly related to local geographic, economic, and historical factors, were the most common source of contamination. E-waste dismantling and chemical production has the greatest impact on PCDD/Fs in different media.

[Distribution, Sources, and Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Tributary Waters of the Lower Reaches of the Yangtze River, China].

The lower reaches of the Yangtze River are a typical gathering place of chemical industrial parks in China. Polycyclic aromatic hydrocarbons (PAHs) emitted in the production process of chemical enterprises enter the tributary water body through atmospheric deposition and surface runoff, and finally merge into the Yangtze River. In this study, the distribution characteristics, source analysis, and ecological risk assessment of PAHs in a series of typical water samples collected in the tributary waters of the Yangtze River were studied. PAH monomers in the samples were mainly low-ring. The total concentration of PAHs was in the range of 37.27 to 285.88 ng·L-1 with a mean value of 78.31 ng·L-1, while the monomer concentration of PAHs ranged from 0 to 61.35 ng·L-1. The lowest detection rate was benzo[k] fluoranthene and benzo[a] pyrene at 75%. As a toxic PAH monomer, the concentration of benzo[a] pyrene ranged from 0 to 11.08 ng·L-1. According to "Water Quality Standards for Drinking Water Sources (CJ 3020-1993)" of China, the concentration of benzo[a] pyrene in a water sample (S12) located near Wuxi City exceeded the limit of drinking water standards (10 ng·L-1). Compared with the total concentration of PAHs in rivers in some typical regions of the world, the concentration of PAHs in this study was generally at low to moderate levels. According to the source analysis results of the ratio method and principal component analysis, the concentration of PAHs in water was mainly affected by fossil combustion, automobile exhaust, and chemical emissions. To assess the potential ecosystem risk of PAHs in the investigated area, the risk quotient (RQ) was used. In addition to the DBA monomer, the relative quantities (RQs) (replication) of the remaining monomers were greater than 1, and the RQ (MPCs) values in all the monomers were less than 1, indicating that the ecological risk of water samples was at a medium level. From the perspective of long-term environmental exposure, appropriate control measures should be considered to prevent further pollution. The results can provide reference for PAH risk assessment and pollution control of chemical industrial parks in the lower reaches of the Yangtze River.