使用保留时间锁定和GC／MS对土壤样品的分析

使用保留时间锁定软件／气相色谱／质谱方法，分析环境土壤样品中农药残留成份，并从567种化合物保留时间锁定农药谱库得以定性分析分析。此方法干扰少、灵敏度高、操作简单、结果准确。可为定量分析提供可靠的依据。

Microbial activity and community diversity in a variable charge soil as affected by cadmium exposure levels and time

Effects of cadmium （Cd） on microbial biomass, variable charge soil （Typic Aquult） using an incubation study activity and community diversity were assessed in a representative Cadmium was added as CdCNO3）2 to reach a concentration range of 0-16 mg Cd/kg soil. Soil extractable Cd generally increased with Cd loading rate, but decreased with incubation time. Soil microbial biomass was enhanced at low Cd levels （0.5-1 mg/kg）, but was inhibited consistently with increasing Cd rate. The ratio of microbial biomass C/N varied with Cd treatment levels, decreasing at low Cd rate （〈0.7 mg/kg available Cd）, but increasing progressively with Cd loading. Soil respiration was restrained at low Cd loading （〈1 mg/kg）, and enhanced at higher Cd levels. Soil microbial metabolic quotient （MMQ） was generally greater at high Cd loading （1-16 mg/kg）. However, the MMQ is also affected by other factors. Cd contamination reduces species diversity of soil microbial communities and their ability to metabolize different C substrates. Soils with higher levels of Cd contamination showed decreases in indicator phospholipids fatty acids （PLFAs） for Gram-negative bacteria and actinomycetes, while the indicator PLFAs for Gram-positive bacteria and fungi increased with increasing levels of Cd contamination.

Heavy metal pollution and potential ecological risk in reclaimed soils in Huainan mining area

In order to determine the environmental quality condition of reclaimed soils inHuainan mining area, soil samples were collected from three representative mines, suchas Panyi Mine, Xinzhuangzi Mine and Datong Mine.The total concentration of Cd, Hg, Cu,Pb and As in the samples were analyzed.The potential ecological risk was used to evaluatethe heavy metals pollution.The investigation reveals that the reclaimed soils are contaminatedto a certain degree and the trace elements in coal gangue transferred to thesurface soil.The order of potential ecological risk is Cd>Hg>Cu>Pb>As; the pollution degreeof each sampling site is arranged in the following order: Xinzhuangzi Mine>DatongMine>Panyi Mine, and the multiform of heavy metals of potential ecological risk index is at357.35～484.62.

The influence of atmospheric Hg on Hg contaminations in rice and paddy soil in the Xunyang Hg mining district,China

To date, the Xunyang mercury(Hg) mining district is the only ongoing large-scale Hg mining district in China. To understand the influence of Hg contamination mode from the Hg mining and smelting activities, 27 sampling sites in the Xunyang Hg mining district were chosen in this study. Total gaseous mercury(TGM) in ambient air was measured using a Lumex-RA915 automatic Hg analyzer in2011. Rice samples and soil samples from rhizosphere were collected systematically and simultaneously. Total Hg(THg) and methylmercury(Me Hg) concentrations in rice grain and soil samples and Hg speciation with modified sequential selective extractions were measured. The local environment was seriously polluted with Hg. The TGM(302 ± 376 ng·m-3, ranging from 24 to 2220 ng·m^(-3)) in the local ambient air, THg(28 ± 30 mg·kg^(-1), ranging from 0.31 to 121 mg·kg^(-1)) and Me Hg(2.3 ± 1.9 lg·kg^(-1),ranging from 0.24 to 8.9 lg·kg^(-1)) in soil samples were at the sample level with Hg contaminated area. The THg concentration(26 ± 16 lg·kg^(-1)ranging from 4.5 to 71 lg·kg^(-1)) in most of the rice grain samples clearly exceeds the threshold level(20 lg·kg^(-1)) in the Chinese national guidelines for cereals(NY 861-2004). The inorganic mercury(IHg)(9.1 ± 5.6 lg·kg^(-1), ranging from 1.2 to 24 lg·kg^(-1)) and Me Hg(14 ± 9.8 lg·kg^(-1), ranging from 2.1 to 59 lg·kg^(-1))concentration in rice grain samples were at the same level with Hg contaminated area. The main species of Hg in paddy soils reveal strong complex Hg and residue Hg. According to the correlation analysis, a Hg pollution mode from local Hg mining and smelting was hypothesized, including Hg emission, transportation, methylation, and uptake process.

Seed Bank of Amorpha fruticosa L. on Some Ruderal Sites in Serbia

Amorpha fruticosa L. （Fabaceae）, known as indigo bush, false indigo bush, false indigo and desert false indigo, is deciduous shrub （1-6 m tall）. The woody weed species A. fruticosa has a high environmental adaptability and is present in different environmental conditions. In Vojvodina region （Northern Serbia）, it is mostly present near irrigation channels and river banks, especially in alluvial or marshy areas. Since A. fruticosa is continually spreading near river banks, the aim of research was to determine seed bank composition near the Danube River. in 2014, soil sampling was performed at localities with high population of A. fruticosa （3-4 plants at age over two years and 10-14 plants at age 1-2 years）. Soil samples were taken from two localities （Futog and Sangaj） with alluvial sandy soil and chernozem near the Danube River. Each sample was sieved through a system of copper sieves of various diameters. After the separation of seeds from samples, they were identified. Significant presence of A. fruticosa seeds （1,914 seeds/m2） was established in a layer of 0-10 cm. In the same soil layer, the significant presence of seeds of Stellaria media （L.） Vill. and Urtica dioica L. were also established. Seeds ofA. fruticosa were not found in soil layers 10-20 cm and 20-30 cm. The invasive weed species A. fruticosa produces a large number of seeds in two cycles. The majority of the seeds stay in the upper soil layer, being dispersed by water （hydrochory）.

Assessment, Composition and Possible Source of Organochlorine Pesticides in Surface Soils from rmqi, China

Twenty-eight surface soil samples from 5 functional zones （park, traffic roadside, business/residential area, rural area, and industrial area） of Uruimqi, China were collected and analyzed for the concentrations of 14 organochlorine pesticides （OCPs）, such as 3 isomers of hexachlorocyclohexane （HCHs） （α-HCH, β-HCH, and γ-HCH）, 4 dichlorodiphenyltrichloroethanes （DDTs） （p,p′-DDT and its metabolites p, p′-DDD （1,1-dichloro-2,2-bis（p-chlorophenyl）ethane） and p,p′-DDE （1,1-dichloro-2,2-bis（4-chorophenyl）ethylene）, and o, p′-DDT）, and methoxychlor, aiming to survey the residue levels and compositions of these 14 OCPs, to identify possible sources of the OCPs, and to assess their potential risks to human health and the environment in surface soils of Ur/imqi. The concentrations ranged from non-detected to 30.86μg kg^-1 for HCHs （sum of α-, β-, and γ-HCH）, from non-detected to 40.03 μg kg^-1 for DDTs （sum of p, p′-DDT, p, p′-DDD, p, p′-DDE, and o, p′-DDT）, and from non-detected to 11.95 μg kg^-1 for methoxychlor. The total concentrations of the OCPs ranged from 16.40 to 84.86 μg kg^-1, with a mean of 41.89 ± 16.25 μg kg^-1. According to the measured concentrations and occurrence rates of the 14 OCPs, DDTs, HCHs, and methoxychlor were the most dominant compounds. Among the 5 functional zones, the total concentration of OCPs was in the order of rural area 〉 traffic roadside 〉 park 〉 business/residential area 〉 industrial area. The different compositions of DDTs and HCHs indicated that the residues of these compounds in most soil samples originated from historical application, besides slight recent introduction at some sampling sites. The results of Pearson correlation analysis showed that soil total organic carbon played an important role in the residue levels of HCHs, but such relationships were not found with DDTs or other OCPs. The soil quality of Uriimqi was classified as Class I based on the guidelines of the Chinese Environmental Quality Standard for Soil （GB15618-1995）, indicating that the residue levels of OCPs have little risks to the environment and human health in the study area.