Wieser, MichaelNasehi Kalajahi, Farnaz2024-08-302024-08-302024-08-28Nasehi Kalajahi, F. (2024). Determination of zinc isotopic composition in biological tissues (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.https://hdl.handle.net/1880/119550Reliable measurement of zinc (Zn) isotopic composition in biological tissues is crucial for understanding zinc metabolism and its role in health. Zinc isotopic ratios, particularly δ66Zn, provide insights into zinc uptake, distribution, and excretion within the body. The primary aim of this study is to develop and refine advanced analytical methods to accurately measure Zn isotopic composition in biological samples, specifically liver and kidney tissues. This study addresses the challenges posed by the inherently narrow range of natural mass-dependent fractionation in zinc, typically confined to ±1‰. Using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) and the double-spike method, the analytical method achieves precision up to 0.1‰. The method ensures low blank levels (below 5 ng) and a high yield recovery rate (95%) during processing. Certified Reference Materials (CRMs) such as Bovine Liver (NIST1577c); Human Hair (GBW07601, USGS42, USGS43); Whole Blood (SeroNorm); Bone Ash (NIST1400); and Bone Meal (NIST1486) were used to validate the accuracy and precision of the method. To further demonstrate the method’s efficacy, Zn isotopic compositions were analyzed in biological samples from mice with different gut microbiota conditions: germ-free, specific pathogen-free (SPF), and Segmented filamentous bacteria group (SFB). These analyses help elucidate the impact of gut bacteria on zinc homeostasis. The method developed provides a robust tool for accurately detecting subtle isotopic variations of less than 0.3‰, which is essential for understanding the complexities of zinc metabolism in biological systems. The successful development and validation of this analytical method mark a significant achievement, setting a new standard in the field of zinc isotopic analysis. This advancement not only enhances the precision and reliability of Zn isotopic measurements but also lays the groundwork for future studies investigating zinc dynamics in biological contexts, thereby contributing to a deeper understanding of zinc metabolism and its implications for health.enStable IsotopesEducation--Sciencesmaster thesis