1. 05/07/2024  Isotopes and human health Zheng group has been involved in studying chronic kidney disease-mineral bone disorder (CKD-MBD) using enriched and stable calcium isotopes. Now the interdisciplinary team was just awarded a prestigious, multi-million dollar NIH R01 grant for 5 years to further this line of research! Besides Zheng (Earth Sciences, co-I), the team includes Prof. Kathleen Hill Galant (Food Science and Nutrition, PI), Prof. Patrick Nachman (Medical School, co-I), and Ms. Rebecca Freese (Clinical and Translational Science Institute, co-I). Very exciting!!!
  2. 04/23/2024  New paper Graduate student Weiming Ding shared his secrets on high-precision analysis of stable Ce isotopes, stable and radiogenic Nd isotopes in a peer-reviewed publication. Congratulations, Weiming! The paper can be found here.
  3. 01/05/2024  Femtosecond laser successfully installed After the long delay related to the global COVID pandemic and supply-chain issues, the fs-LA system is now finally installed and working in Zheng's lab! This new instrument brings us unique capability for in-situ isotopic analysis, and it opens the door to some new and exciting research opportunities!
  4. 12/16/2023  Zheng group at AGU! Zheng group had a great turnout at AGU Fall meeting in San Francisco this year. Weiming gave his first in-person talk at AGU, and Charin and Dylan gave their first in-person poster presentations, and Xinyuan gave an invited talk. Postdoc Guy Evans from Bill's group also presented exciting K isotope results from Lost City hydrothermal field - a collaborative effort between the two groups!
  5. 09/21/2023  Femtosecond laser! Two crates that contain the femtosecond laser ablation system have finally arrived at Tate Hall after more than one year's wait.
  6. 08/14/2023  A special guest to the group Sam Houk, Professor Emeritus of Chemistry at Iowa State University, visited our mass spectrometry lab and had conversations with Zheng and his students on the latest development of ICP-MS instruments. Sam invented the technology that is now known as ICP-MS, one of the most sensitive and widely used methods for elemental and isotopic analysis. A lot of fundamental understanding we have about ICP-MS today came from the work by Sam and his coworkers.
  7. 06/14/2023  Doctoral Dissertation Fellowship Emily Briggs, a graduate student from the Department of Anthropology who works in our lab for Sr isotope analysis, has been awarded a highly competitive Doctoral Dissertation Fellowship from the University. Emily will continue to work in our labs to complete the project for her thesis relevant to repatriation of undocumented human remain collections using isotopic tools. Congratulations!
  8. 02/10/2023  NSF CAREER Award Xinyuan receives a NSF CAREER Award that supports his stable K isotope research in the next 5 years! Very exciting!
  9. 12/30/2022  An invited talk Invited by Deep-Sea Multidisciplinary Research Center at Qingdao National Laboratory for Marine Science and Technology (China), Xinyuan gave an online presentation on stable K isotopes. The ~2-hour seminar attracted over 300 online attendees from China and a few other countries, including USA.
  10. 12/06/2022  A new student to the group Keegan Hoffer joins our group as a Master student. He will start in the coming Spring semester. Welcome, Keegan!
  11. 11/09/2022  Mercury (Hg) isotopes and Mesozoic Oceanic Anoxic Events (OAEs) We are funded by American Chemical Society Petroleum Research Fund (ACS-PRF) to better understand environmental controls on the production and preservation of organic-rich sediments during several Mesozoic OAEs using stable Hg isotopes! Exciting!
  12. 11/03/2022  Visit to University of South Carolina Xinyuan visited the School of Earth, Ocean, and Environment at University of South Carolina and gave a departmental seminar. It is nice to enjoy some warm sunshine at Columbia, SC, before winter hits Minnesota!
  13. 08/29/2022  Iron isotopes in seafloor sulfide mound A new study coauthored by Xinyuan just came out in Communications Earth & Environment. The study looked at Fe isotope variations in seafloor hydrothermal sulfide mound, with implications for the use of Fe isotopes to better understand formation of massive sulfide deposits. The work was led by collaborators in Peru and Europe. More details in "Publications".
  14. 08/18/2022  Metal isotopes and human health An invited commentary coauthored by Prof. Katie Hill Gallant at FScN and Xinyuan just appeared online in a top peer-reviewed nephrology journal Kidney International. It discusses the potential of stable Ca isotopes in early diagnosis of chronic kidney disease (CKD) - bone mineral disorder. Want to know more? 50-day free download from here.
  15. 08/16/2022  Undergraduate Research Opportunities Program (UROP) award Undergrad Owen Wold is funded by UROP to work on K isotopes in altered oceanic crust this Fall. Congrats, Owen!
  16. 07/07/2022  New publication: K isotope application in agriculture A new study from Zheng isotope geochemistry group has been just accepted for publication in ACS Earth and Space Chemistry! This time, we demonstrated how K isotopes can help better accurately quantify K fertilizer uptake by plants - a novel approach of great potential in pushing our understanding of the K nutrient cycle in soil–plant systems.
  17. 06/10/2022  Student research grants awarded! Charin and Weiming were both selected to receive GSA student research grants to support their PhD research projects. Charin will work on K isotope systematics in hydrothermal systems using combined laboratory experiments and analysis of natural samples. Weiming will work on developing stable Ce isotopes as a possible new tracer for redox conditions and Mn cycling in early Earth. Congratulations! Keep up the good work, both!
  18. 06/09/2022  The first study on potassium (K) isotope systematics in modern hydrothermal vents A new study led by Xinyuan and collaborators at UW-Madison and University of New Hampshire was just published in EPSL. This study provides the first glimpse into K isotope systematics in modern hydrothermal fluids. This work precludes high-temperature hydrothermal systems as the cause for the heavy seawater K isotope composition, but implies the significant role of authigenic clay formation ("reverse weathering") in the global K, hence carbon, cycle. This work also highlights the possibility for dramatically different K isotope composition in the Ordovician seawater, which could be linked to significantly higher reverse weathering during that time.
  19. 05/18/2022  New publication: Pa, Th, laser ablation, and mass spec A new study led by our collaborators in China was just accepted for publication in Analytical Chemistry. Xinyuan is a coauthor on the paper. This study developed a novel technique for measuring 231Pa and 230Th in marine sediments by laser ablation mass spectrometry. Pa and Th are important geochemical tracers with a wide range of oceanographic and paleoceanographic applications, ranging from tracing sedimentation rates to ocean circulation. Our new method opens up new opportunities and facilitates the use of Pa and Th in ocean science research. See "Publications" for more details!
  20. 05/03/2022  Calcium isotopes, cave deposits, and climate A new project led by Prof. Larry Edwards was just funded by NSF to investigate isotope records in Asian cave deposits and their implications for past climate. Xinyuan is the co-PI on the project, and my group will spearhead an investigation on Ca stable isotopes in these cave carbonates! 
  21. 04/27/2022  Secrets about how to use "Sapphire" for K isotope analysis? After an over 1-year delay to the installation of our new collision-cell MC-ICP-MS "Sapphire" due to the COVID pandemic, we can now declare our machine (SP006) is working! Our K isotope data quality is among one of the best in the world! A new study on how we make such high-precision K analysis on "Sapphire" has just been accepted for publication in JAAS (you can download it from here)! 
  22. 03/25/2022  New publication A new study that Xinyuan co-authored just came out in Earth-Science Reviews. If you want to learn more about the Fe cycling and nutrient availability of the early Earth and the implications for the early biosphere, please check out the paper in "Publications"! 
  23. 03/23/2022  Postdoc departure Xinyang departed the group today, and he is taking up a permanent position as a professor in Chengdu University of Technology! He will soon have a fancy isotope geochemistry facility. Congratulations, Xinyang!
  24. 01/28/2022  Undergraduate researchers Three undergraduates, Michael Ysaguirre, Jayva Jordan, and Owen Wold, has joined in our group this semester for directed studies research projects on the global K cycle and Mesozoic OAEs. Welcome!
  25. 10/05/2021  New papers online Two new papers are online now - one is an invited review on stable K isotopes, and the other one deals with Nd paradox in the South Atlantic. See publication section for more details!
  26. 06/21/2021  To the Antarctic!!! A major project led by Zheng at UMN in collaboration with Professor Howie Scher at University of South Carolina is funded by NSF! This project intends to study marine Nd isotope and rare earth element cycles in the Amundsen Sea near the Antarctic continental shelf. The overarching goal is to better understand the biogeochemical cycle of trace metal nutrients in an area that witnesses the fastest ice shelf melting around the entire Antarctica in the past few decades. This project is part of the larger collaborative US GEOTRACES program.
  27. 06/21/2021  New graduate students this Fall. Three graduate students - Soisiri Charin, Weiming Ding, and Yuchi Zhang – will be joining in the group this coming Fall! Excited to see the group grow! Welcome!
  28. 02/05/2021  New undergraduate researchers to the group. Two talented and enthusiastic undergrads – Camryn Jordan and Keegan Hoffer joined the group as undergraduate researchers. They will work on exciting projects related to the global biogeochemical cycle of potassium. Welcome, Cam, Keegan!
  29. 03/13/2020  A new triple-quad ICP-MS is funded by NSF. A new triple-quad ICP-MS specialized in multi-element concentration measurements is funded through a NSF proposal where Prof. Bill Seyfried is the lead PI, and Zheng is one of the co-PIs with Assoc. Prof. Cara Santelli and Prof. Larry Edwards. A great addition to the analytical capability of geochemistry groups in the department.
  30. 12/24/2019  A Christmas gift of the group: a new MC-ICP-MS "Sapphire" (Nu Instruments) was ordered, and will arrive soon. The instrument is equipped with a collision cell, 16 Faraday cups, 1 Daly detector, 5 electron multipliers, a combination of high (10e12) and low (10e10) resistors on 13 Faraday cups. The instrument is capable of high-precision isotope ratio analysis for a wide range of elements in the periodic table.