Veröffentlicht am: 15.02.2016
The Helmholtz Centre for Environmental Research (UFZ) with its 1,100 employees has gained an excellent reputation as an international competence centre for environmental sciences. We are part of the largest scientific organisation in Germany, the Helmholtz association. Our mission: Our research seeks to find a balance between social development and the long-term protection of our natural resources.
The global distribution and organochlorine precipitation of pesticides plays an important role in environmental protection and human health. World wide spread of persistent organochlorine pesticides (OCPs) is of major concern as well as their bioaccumulation within the trophic levels in food webs. It is known that the concentration of OCPs increases in the food chain of organisms due to biomagnification. It is not only relevant to quantify the amount of augmented contaminants but also to determine its origin and transformation pathways in organisms. Compound-specific stable isotope analysis (CSIA) holds promising approaches for assessing the fate of organic pollutants in the environment. However, the main obstacle for CSIA is the low sensitivity which is approximately 100-fold less than conventional gas chromatography-mass spectrometry (GC-MS). Thus, one of the major challenging for investigating bioaccumulation of OCPs in food web using CSIA is how to extract OCPs from large amount of biota samples in order to meet the detection limit of CSIA. Moreover, due to the high lipophilicity, separation of OCPs from lipids remains as another challenging.
Therefore, appropriate methods for biota sample treatment are necessary to be developed. We select hexachlorocyclohexane (HCHs) as model compound of OCPs, and have developed a combined methods of liquid-liquid extraction, saponification, sulfuric acid treatment, as well as column chromatography for extraction and clean-up of HCHs from plants, wood, milk, fish oil and pork liver. These biota matrixes have high accumulation potential of HCHs and represent complex matrix for food web study. Our preliminary results show good efficiencies in lipid removal, recoveries of target compounds, and most importantly give no isotopic effect.
The main focus of the study is to investigate in details on the extraction and clean-up techniques of HCHs for CSIA in plants, wood, milk, fish oil and pork liver. The preliminary developed methods need to be developed for the recovery, the quantitative and accurate determination of isotope composition of HCHs. Then the methods will be applied for extracting HCHs from contaminated biota samples from the Bitterfeld region.
The study can start from 11th of April and will take up to 3 months for internship, or 6 months for master thesis. This topic is part of a PhD thesis.
Equal opportunities are an integral part of our personnel policy; we therefore particularly welcome applications from qualified women. Severely disabled persons are given priority where applicants are equally qualified.
Your contact for any questions you may have about the job:
Mrs. Langping Wu
Closing date for applications:
Place of work: Leipzig
Please use our online application system for your application.
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