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Glenn,

      We have been using a NewWave Micromill for some of the otolith
research work we are involved in. Brassler makes an assortment of
different drill bits for various applications. Attached is there website
detailing some of their carbide and diamond drill bits. We are currently
using a carbide shank (H52 003) to core out some of our otoliths. The
down side is that these bits due pose a possible contamination problem,
depending on what elements you are analyzing. Most of the diamond drill
bits we looked into were to large, so we opted for carbide tips with
several steps at the end to clean our otolith samples. You can contact
me off-line if you need more information.

                                                      Good Luck!
                                                      Bryan

http://www.brasselerusa.com/products/labCarbidesdisplay.cfm?id=90

Bryan Taplin
Environmental Scientist
US Environmental Protection Agency
NHEERL- Atlantic Ecology Division
27 Tarzwell Drive
Narragansett, RI 02882
Tel. (401) 782-9607
Fax (401) 782-9710




                                                                        
             "Piercey, Glenn"                                           
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             Sent by: Stable                                         To 
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             Geochemistry                                            cc 
             <ISOGEOCHEM@list                                           
             .uvm.edu>                                          Subject 
                                      Re: [ISOGEOCHEM] Micromill drill  
                                      bits                              
             06/26/2008 03:13                                           
             PM                                                         
                                                                        
                                                                        
              Please respond                                            
                    to                                                  
              Stable Isotope                                            
               Geochemistry                                             
             <ISOGEOCHEM@list                                           
                .uvm.edu>                                               
                                                                        
                                                                        




We have recently purchased a NewWave Micromill and now need to find
drill bits. We will be drilling carbonates (otoliths, shell, corals) and
would like to purchase the smallest possible size. Our SIMS spot size
for these is around 5 -10 um the smallest bit I have found is 38 um
(UKAM), the bit provided was around 60 um. What drill bit point works
best to create powders?

Also, we will be working with sulphides and would like to try a coring
bit. Most of the diamond bits I have found have trace metals in the
epoxy holding the diamonds. Has anyone found alternatives such as
ceramic?

Any help appreciated. Thanks.

Glenn Piercey
Microanalysis Facility INCO Innovation Center (MAF-IIC)
Memorial University
709-737-3314
709-737-6193 Fax
http://www.mun.ca/creait/maf/



From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On
Behalf Of Julie Hamilton
Sent: Thursday, June 26, 2008 10:34 AM
To: [log in to unmask]
Subject: Re: [ISOGEOCHEM] A question on degraded collagen

Dear Ada
the obvious answer is that the results are probably not much use as you
have no way of knowing whether they come from collagen or other,
intrusive substances. there has been some discussion of this subject
within the AMS-radiocarbon dating community however who may have to work
with very small amounts of dodgy collagen - see e.g. Brock, F., Bronk
Ramsey, C. & Higham, T.F.G., (2007), Quality assurance of ultrafiltered
bone dating, Radiocarbon, 49(2),187-192 : Proceedings of 19th
International Radiocarbon conference - I don't know if it is of any
relevance to your problem but they've thought harder about collagen than
most people!
best wishes
Julie Hamilton
Research Laboratory for Archaeology and the History of Art
Dyson Perrins Building
South Parks Rd
OXFORD OX1 3QY

email: [log in to unmask]
Tel: (01865 ) 285203