Hi! I am a graduate student studying the trace metal accumulation in several aquatic plants and in sediments using ICP-MS.
I am having trouble?generating reliable data however. Using EPA digestion methods 3051 and 3021 I am only able to get between 0-10% recoveries on my reference standards.? I can't figure out what I am doing wrong! Has anyone used ICP-MS to study plant and sediment samples?? If so, would you mind reading on to help me discover where I'm going wrong?? I feel like it's something?obvious and right in front of me, but I am just unable to see my error! Ok,? here's what I have done to the samples... 1.? For microwave digestion I tried both EPA 3052 and EPA 3051 (3052 for plant samples only, 3051 for both plant and sediment reference standards)? I followed these methods exactly, using only nitric acid.? 2.? Following digestion the samples were centrifuged and decanted. 3.? Samples were diluted 100x.? (.5mL of digestate, 2.5mL of HNO3, .5 g Yttrium, and brought to 50g with DI water) 4. Samples were run on the ICP-MS (the daily performance and internal standards were all acceptable) 5. Data reported by the ICP is in ppb while the data reported by the reference standards are in ppm, so I first corrected each raw element data for the blank, then the dilution factor.? Then I converted ppb to ppm and calculated percent recovery. Again,?most recoveries were within 0-10% of the certified values. I am thinking that one thing I am not properly accounting for is the initial weight of the dry sample being digested.? However one of the reference standards used the same mass I am using (0.1g). Because most of the?% recovery values I have are within 10% of each other I suspect I am making a systematic error somewhere in?this process. ? I would really appreciate any suggestions or guidance to correct this problem.? I am out of ideas! Thank you! Lesley -----Original Message----- From: Jim Schneider <[EMAIL PROTECTED]> To: [email protected] Sent: Mon, 8 Oct 2007 3:25 pm Subject: Study in Africa in 2008: Conservation and Biodiversity in South African Parks and Nature Reserves Study in Africa in 2008 Conservation and Biodiversity in South African Parks and Nature Reserves May 10 to June 5, 2008 Have you always wanted to go to Africa? To see, study, and explore the rich diversity of wildlife and natural resources? Here's an amazing opportunity to do just that! In Summer 2008, the Department of Fisheries and Wildlife, through the Office of Study Abroad, at Michigan State University will be making it's 4th, 4-week excursion to South Africa, to explore the Conservation and Biodiversity of their Parks and Nature Reserves. We'll tour various parks and nature reserves throughout South Africa, including Timbavati Private Nature Reserve, Kruger National Park, Manyeleti Nature Reserve, Pilanesberg Game Reserve, Kalahari Transfrontier Park, De Hoop Nature Reserve, Agulhas National Park, Boulders African Penguin colony, Cape of Good Hope, Table Mountain National Park and Robben Island. At a time when natural resource managers are asked to consider global contexts of biodiversity and ecosystem approaches to management, this course will expose students to various South African ecosystems and will broaden students' scope of management by taking into account the impacts that land-based activities and international policies have on the natural communities in these ecosystems. The role of game reserves, nature reserves, and national parks as management tools will be investigated and students will be introduced to social issues that are encountered when protection of biodiversity restrictions are imposed on a society. We will also address the role of hunting as a management tool of big game species on private game reserves and the impact of hunting on the surrounding communities. Students will familiarize themselves with the flora and fauna of the different ecosystems visited; will interact with government officials and land managers; and will participate in hands-on learning, including bushwalks, habitat sampling, population surveys and other field experiments. This program is perfectly suited for undergraduate students studying ecology, natural resources, and wildlife biology, ecology and/or management. We can take a maximum of 12 students. Preference is for Wildlife/Natural Resource type students with an ecology background, but students from other biological majors that are passionate and excited about exploring South African wildlife and natural resources are also encouraged to apply. Each student participating in this programs enrolls in 6 credits of FW 480 - International Studies in Fisheries and Wildlife at MSU. While this is a Michigan State University program, students from non-MSU colleges and universities are welcome and encouraged to apply. Over the past 3 summers students from Ball State University, Central Michigan University, Paul Smith's College, University of Tennessee, and the University of Vermont have participated in this program. Non-MSU students enroll as Lifelong Education students and tuition rates are nearly equal to those of in-state MSU students. Students also must pay a program fee (last year it was $3,633), which covers almost everything (transportation, lodging, field trips, park fees, and most meals) while you're in country, and their airline ticket (approximately $1,600). While it sounds like a lot of money, for everything you get to see and do for 4 weeks in Africa, it's truly a bargain. It's truly a life altering experience. Join Us!! See the following OSA website for some additional information - http://studyabroad.msu.edu/programs/safricacon.html Don't wait to apply. We expect to be full by January 2008. Feel free to contact me if you have any questions or want more details. Jim Schneider [EMAIL PROTECTED] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Jim Schneider - Academic Adviser Undergraduate Advising Center Department of Fisheries and Wildlife Michigan State University 40 Natural Resources Building East Lansing, MI 48824-1222 Office: 517-353-9091 Fax: 517-432-1699 E-Mail: [EMAIL PROTECTED] FW Web Site: <http://www.fw.msu.edu/> http://www.fw.msu.edu/ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ________________________________________________________________________ Email and AIM finally together. You've gotta check out free AOL Mail! - http://mail.aol.com
