A novel sample preparation method based on polarity grouping for comprehensive determination of 315 pesticides and other contaminants in wolfberry by liquid chromatography-tandem mass spectrometry.

A novel sample preparation method based on polarity grouping was developed for the comprehensive determination of 315 undesirable low-weight organic pollutants ranging from polar to weakly polar in wolfberry. The method involves the swelling of the sample in ammonium acetate buffer, two-phase extraction, three-phase extraction, and dispersive solid phase extraction (D-SPE) with the assistance of low-temperature centrifugation and analysis by ultrahigh performance liquid chromatography coupled with electrospray ionization tandem mass (UHPLC-ESI-MS-MS) by using the multiple reaction monitoring mode. The recoveries of the analytes with wide range of polarity were satisfactory.

[Pollution Characteristics and Source Apportionment of Atmospheric Volatile Organic Compounds in Winter in Kaifeng City].

In order to explore the pollution characteristics and sources of atmospheric volatile organic compounds (VOCs) in winter in Kaifeng City, based on the atmospheric VOCs component data obtained from the online monitoring station of the Kaifeng Ecological and Environmental Bureau (Urban Area) from December 2021 to January 2022, the pollution characteristics of VOCs and secondary organic aerosol formation potential (SOAP) were discussed, and the sources of VOCs were analyzed by using the PMF model. The results showed that the average mass concentration of VOCs in winter in Kaifeng City was (104.71±48.

A generic and rapid analytical method for comprehensive determination of veterinary drugs and other contaminants in raw honey.

A generic, rapid, simple and low-cost analytical method for simultaneously screening and confirming 400 veterinary drugs and other contaminants in raw honey was developed. The method was based on one-step extraction and ultra-high performance liquid chromatography coupled with electrospray ionization and tandem mass spectrometry. A well-designed extraction method results in the complete precipitation of proteins and separation of analytes from carbohydrates and reduces the time and cost of analysis by covering polar to non-polar analytes.

[Accurate Identification of Ambient VOCs Emission Sources in an Industrial Park Using On-Line Monitoring Data].

To accurately identify and locate ambient volatile organic compounds(VOCs)emission sources in industrial parks, a continuous online GC-FID method was used to monitor 43 kinds of VOCs on an hourly basis during January 2017 at five sites in an industrial park. A statistical analysis and a PMF model were used to analyze the sources of VOCs, and by combining with CPF and enterprise emission information, the location of each pollution source was accurately identified. The average VOCs concentration was 56.

[Spatio-Temporal Variations and Source Apportionment of Carbonaceous Species in PM Across Multiple Sampling Locations in the Chengdu Plain].

To understand the characteristics and sources of carbonaceous aerosols, one-year PM samples were analyzed for their organic carbon (OC) and elemental carbon (EC) content, following the thermal/optical transmission protocol in three cities[Deyang (DY), Chengdu (CD), and Meishan (MS)] in the Chengdu Plain. The observed annual average concentrations (μg·m) were in the following order:MS (15.8±9.

[Characteristics of Ambient VOCs at the Shuangliu Site in Chengdu, China, During Summer and Autumn].

To better understand the characteristics and sources of ambient volatile organic compounds (VOCs) in a polluted area in Chengdu, which requires air pollution control, samples were collected hourly at the Shuangliu site from August 2016 to December 2016. Online gas chromatography/mass spectrometry and a flame ionization detector (GC/MS-FID) were used to analyze the mixing ratios and compositions of the VOCs. During the sampling period, the average mixing ratios of the VOCs were (45.

Particulate pollution in urban Chongqing of southwest China: Historical trends of variation, chemical characteristics and source apportionment.

Chongqing, the largest megacity in southwest China, faces serious aerosol pollution but lacks information on particle characteristics and its sources. Official data released by Chongqing Environmental Protection Bureau demonstrated that urban PM concentrations decreased remarkably from 150μgm in 2000 to 90μgm in 2012. However, only several peer-reviewed studies paid attention to local fine particle (PM) pollution.

[Study on critical loads of sulfur and nitrogen in the Pearl River Delta].

Supported by the geographical information system (ArcGIS), critical loads and exceedances of critical loads of sulfur and nitrogen in the Pearl River Delta (PRD) were calculated using Steady-state Mass Balance method with current deposition data, vegetation data and soil data obtained by field sampling and laboratory analysis. Results showed that the present critical loads of sulfur were high in the eastern PRD and low in the west. Higher critical loads occurred in most of Huizhou, north-central Guangzhou, Dongguan and south Zhongshan.

Characteristics and formation mechanism of a heavy air pollution episode caused by biomass burning in Chengdu, Southwest China.

To track the chemical characteristics and formation mechanism of biomass burning pollution, the hourly variations of meteorological factors and pollutant concentrations during a heavy pollution on 18-21 May, 2012 in Chengdu are presented in this study. The episode was the heaviest and most long-lasting pollution event in the historical record of Chengdu caused by a combination of stagnant dispersion conditions and enhanced PM2.5 emission from intensive biomass burning, with peak values surpassing 500 μg m(-3).

[Characteristics of haze and its impact factors in four megacities in China during 2006-2009].

The meteorological and environmental data including visibility, SO2, NO2 and PM10 were collected in four major megacities (Beijing, Shanghai, Guangzhou and Chengdu) in the years 2006-2009. Based on the data, seasonal and annual variations of the haze frequency and the key impact factors were discussed. The results indicated that the highest frequencies of haze occurred in summer, winter, spring and autumn for Beijing, Shanghai, Guangzhou and Chengdu, respectively.

Long-term trends and characteristics of visibility in two megacities in southwest China: Chengdu and Chongqing.

Visibility is a good indicator of air quality because it reflects the combined influences of atmospheric pollutants and synoptic processes. Trends in visibility and relationships with various factors in Chengdu and Chongqing, two megacities in southwest China, were analyzed using daily data from National Climatic Data Center and the Air Pollution Index (API) of the Ministry of Environmental Protection of China. Average annual visibility during the period of 1973-2010 was 8.

[Optimization of PM10 monitoring network in Beijing].

PM10 monitoring network in Beijing was classified using a new technique, positive matrix factorization (PMF). And then the removal bias of each cluster was calculated by GIS system and sites with redundant information were identified. The daily average mass concentrations of PM10 from July 2007 to June 2008 were analyzed at 26 sites.

[Modeling the vehicle pollution in the urban streets before and during the Beijing Olympic Games traffic control period].

In order to investigate the vehicle pollution situation in the streets in Beijing and the abatement during the Olympic Games, the OSPM model was applied to calculate the concentrations of PM10, CO, NO2 and O3 inside the urban streets of Beijing before and during the Olympic traffic controlling period in July, 2008. The modeled concentrations before the traffic control are 146 micog/m3, 3.83 mg/m3, 114.

[Assessing PM10 and SO2 networks using positive matrix factorization in Beijing city].

The aim of this study was to identify city areas with similar air pollution characteristics and determine which sites may be providing redundant information. Positive matrix factorization (PMF) was applied in this study to assess the mass concentrations of sulfur dioxide (SO2) and particulate matter with an aerodynamic diameter less than 10 microm (PM010), collected in the air quality monitoring network in the year of 2000. The analysis indicated that there were obviously seasonal variations for PM10 and SO2 in Beijing.

[Estimation of VOC emission from forests in China based on the volume of tree species].

Applying the volume data of dominant trees from statistics on the national forest resources, volatile organic compounds (VOC) emissions of each main tree species in China were estimated based on the light-temperature model put forward by Guenther. China's VOC emission inventory for forest was established, and the space-time and age-class distributions of VOC emission were analyzed. The results show that the total VOC emissions from forests in China are 8565.

[Development of vehicular emission inventory in China].

The vehicular emission inventories with high spatial resolution of 40km x 40km are developed using GIS technique based on the statistic data from yearbooks about vehicles and roads at provincial level in China for the year 2002, and on the emission factors calculated by COPERT III model for each category of vehicles in urban, rural and highway traffic. The results show that the emissions of CO, NOx, NMVOC and PM10 are 28.15, 3.