| Summary: | 碩士 === 國立清華大學 === 生醫工程與環境科學系 === 96 === Abstract
As an important industrial metal, cadmium is widely used in industrial and household products. Since the environment continues to be contaminated with it, the health considerations caused by cadmium has attracted more and more attention. Owing to cadmium can cause severe damage to a variety of organs in human, investigations about the biological toxicity and toxicological mechanisms of novel cadmium-containing materials is growing important. Up to now, there is still lack of adequate analytical technique can provide dynamic information of cadmium in living animals. Accordingly, the integrity and applicability of those analytical results are invariably compromised.
Quantum dots (QDs) are cadmium-containing semiconductor materials on the nanometer scale. The unique properties of QDs, such as broad UV excitation, narrow emission, high quantum yield, and high bioavailability, make them appealing as in vivo and in vitro fluorophores for biomedical imaging. However, the lack of toxicology-based studies renders the discrepancies in the current literature regarding the toxicity of QDs. In order to in-vivo assess the stability of cadmium-containing QDs and evaluate the antagonistic effect between cadmium and selenium in the liver of an anesthetized rat, an in-vivo and in-situ dynamic analytical platform named Microdialysis-Desalter-ICP-MS was aimed to be developed in this study.
Owing to the extremely high salt content and the low concentration of analyte elements, direct determination of trace elements in the microdialysate is considered to be impossible for current instrumentation techniques. For purpose of overcoming the severe matrix effect resulted from the extremely high salt content in the microdialysate samples, an on-line carbohydrate membrane desalting device was used to remove the salt matrix prior to the ICP-MS detection. It has been demonstrated that under the optimized conditions, the detection limit obtained with the proposed method can be controlled to below 1 μg/L, and more than 99.9% of sodium ion can be removed. Besides that, the long term stability of this analytical system can be controlled within 5%. Based on the animal experiment, the feasibility of the developed method for continuously monitoring the dynamic variation in the concentrations of diffusible cadmium and selenium in the liver of anesthetized rat has also been confirmed after injecting cadmium-containing QDs, Na2SeO4及CdCl2 solutions.
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