Journals
  Publication Years
  Keywords
Search within results Open Search
Please wait a minute...
For Selected: Toggle Thumbnails
Occurrence of Antibiotics in Water, Sediments and Seafood in Aquaculture Area of the Pearl River Estuary
HAO Hongshan, XU Yaru, GAO Yue, WANG Zhifen, LI Jie, XU Nan
Acta Scientiarum Naturalium Universitatis Pekinensis    2018, 54 (5): 1077-1084.   DOI: 10.13209/j.0479-8023.2018.018
Abstract793)   HTML    PDF(pc) (571KB)(563)       Save

The occurrence of 22 antibiotics in water samples, sediments, fish and shellfish in aquaculture area of the Pearl River Estuary (Zhuhai and Daya Bay) was studied, using ultrasonic extraction combined with ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The main pollutants detected in aquaculture area of the Pearl River Estuary are quinolones such as norfloxacin, ofloxacin, ciprofloxacin and flumequine. Higher Σantibiotics were observed in Zhuhai Bay in water and sediments compared with Daya Bay. The concentrations of antibiotics in water samples, ranging from 0.13 (sulfamethoxazole) to 4.68 (spectinomycin) ng/L on average, were strongly affected by precipitation. The concentrations of antibiotics in sediments, ranging from 0.02 (isochlortetracycline) to 8.77 (spectinomycin) ng/g (dry weight) on average, accumulated over time. The concentrations of antibiotics in seafood ranged from 0.06 (sulfamerazine) to 46.75 (norfloxacin) ng/g (dry weight). The concentration levels of antibiotics in shellfish and fish were similar and did not show any significant difference. The correlation analysis showed that the concentration levels of antibiotics among sediments were the same; for most seafood, it was same; and for water samples, the difference was great.

Related Articles | Metrics | Comments0
Fast Determination of Multiple Antibiotics in Mussels Based on Extraction and UPLC-MS/MS
XU Yaru, LI Jie, WANG Zhifen, GAO Yue, XU Nan
Acta Scientiarum Naturalium Universitatis Pekinensis    2018, 54 (5): 1060-1066.   DOI: 10.13209/j.0479-8023.2018.009
Abstract661)   HTML    PDF(pc) (1458KB)(221)       Save

A fast and simple method for simultaneous determination of fifteen antibiotics (sulfadiazine, ciprofloxacin, penicillin, spechromycin and roxithromycin) in mussels using ultrasound extraction, solid phase extraction purification and ultra performance liquid chromatography-tandem mass spectrometric was established. The mussel samples were extracted by ultrasonic extraction, followed by solid-phase extraction (SPE) as the cleanup procedure. Ultra performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MS/MS) was used for identification and quantification of antibiotics. The performance of two kinds of SPE cartridges, Oasis HLB and Oasis PRiME HLB, was compared, with the latter showing better results. Recoveries ranged from 64% to 121% at spiking levels of 50 ng/g, with RSD being 0.5%–19%, and from 67% to 117% at spiking levels of 100 ng/g, with RSD being 1%–9%. Limits of detection (LODs) ranged from 0.004 to 0.5 ng/g (dry weight) and limits of quantification (LOQs) ranged from 0.013 to 1.67 ng/g (dry weight). The recoveries were reasonable and the detection limit was low. Finally, the method was successfully applied to the determination of the target antibiotics in mussel samples (Hyriopsis cumingii) collected from Poyang Lake. 9 out of 15 selected antibiotics were detected in the collected mussel tissues. The concentration and detection frequency of trimethoprim in mussels were the highest. The concentration of trimethoprim was 78.8 ng/g, followed by spectinmycin (41.2 ng/g) and ciprofloxacin (39.8 ng/g).

Related Articles | Metrics | Comments0
Removal of 17β-estradiol in a Bio-electro-Fenton System
ZENG Yaqiong, WANG Binwei, LI Jie, XU Nan
Acta Scientiarum Naturalium Universitatis Pekinensis    2016, 52 (5): 939-946.   DOI: 10.13209/j.0479-8023.2016.039
Abstract1322)   HTML    PDF(pc) (681KB)(814)       Save

Bio-electro-Fenton (BEF) system is an emerging advanced oxidation process, which can not only generate electricity and degrade organic substrates via bio-oxidation on the anode, but also remove bio-refractory pollutants via Fenton’s reaction on the cathode. The bio-electro-Fenton system was applied to the removal of trace estrogens, and both the removal efficiency and the optimization of performance were investigated in the bioelectro-chemical system equipped with the Fe@Fe2O3/non-catalyzed carbon felt (NCF) degradation mechanism, including external resistance, the cathode iron content, aeration rate and catholyte pH. It was found that chemical oxidation was the main pathway for E2 removal, and external resistance was the most significant factor influencing E2 removal rate, and the E2 removal was maximized when the external resistance was close to the internal one. The systems with Fe@Fe2O3/NCF cathode showed a high E2 removal performance under the optimized conditions, mostly over 90%.

Related Articles | Metrics | Comments0
Study on Early Cretaceous Stress Fields and Geological Significance of Lingshan Island
LI Jie, JIN Aiwen, HOU Guiting, FU Wenzhao, YANG Zhiqiang2
Acta Scientiarum Naturalium Universitatis Pekinensis    2015, 51 (6): 1069-1077.   DOI: 10.13209/j.0479-8023.2015.076
Abstract1154)      PDF(pc) (2047KB)(973)       Save

Four periods of structural stress fields can be recognized during Early Creraceous in Lingshan Island and adjacent areas based on field geological investigation and summary of the previous data, which is derived from the occurrence data of the stress response structures, i.e., X-type shear jointing, dykes and folds. They are the tectonic stress period of extension in the direction of NW formed the offshore basins during the Laiyang stage, followed extrusion in the direction of NW in the late Laiyang stage, during the Qingshan stage further extension in the direction of NW turned the offshore basins into rift basins, and followed basin inversion in the direction of NW in the late Early Cretaceous. It is concluded that the two extensional phases in Early Cretaceous were dynamically associated with either gravity collapse or lithospheric delamination of the thicked crust or lithosphere in North China and the NW-SE extrusion records the effect by the transmission of the NW-directed subduction of Izanaqi plate to the NW-directed subduction of paleo Pacific plate towards the bottom of the Asian continent.

Related Articles | Metrics | Comments0
Relationship between Perfectionism and Job Burnout of Architects
LI Jie,GAN Yiqun,ZHOU Yu
Acta Scientiarum Naturalium Universitatis Pekinensis   
Numerical Simulation of Atmospheric Boundary-layer Structure over Urban and Rural Areas
LIU Shuhua,LI Jie,WEN Pinghui
Acta Scientiarum Naturalium Universitatis Pekinensis   
Abstract627)            Save
A transfer model is established, which can be used to study the interaction between the land surface physical processes of inhomogeneous region and the structure of atmosphere boundary-layer over urban and rural terrains. The model has simulated surface heat flux, surface temperature, temperature profiles, height of mixture layer and so on. And the differences between urban area, suburban area and rural area have been compared. This model mainly depends on the parameters below: surface albedo, surface roughness coefficient, moisture available coefficient of soil, thermal capacity and thermal diffusion coefficient of errain,cloudage. The result shows that this model can simulate the structure and eigenvalues of atmosphere boundary layer and their changes in a day. Parameters used in this model aim at Beijing City, and the time is at the beginning of September. To other cities, or other time, the parameters should be adjusted accordingly. In addition, being adjusted, the model can also be used for other homogeneous and inhomogeneous terrains.
Related Articles | Metrics | Comments0