Regarding carbon (and N, S, O, H, etc) isotopic reference materials, please see: http://www.iaea.org/programmes/aqcs/ordering_rms_hyd.htm USGS40 L-glutamic acid has d13C = -26.24 per mill relative to VPDB and d15N = -4.52 per mill relative to N2 in air USGS41 L-glutamic acid has d13C = +37.76 per mill relative to VPDB and d15N = +47.57 per mill relative to N2 in air Other isotopic reference materials now available include: USGS34 KNO3 (low d18O value of -27.9 per mill relative to VSMOW) USGS35 NaNO3 (high d18O of +57.5 per mill relative to VSMOW and high d17O of +51.5 per mill relative to VSMOW) ISL-354 NaCl (newly available Cl isotopic reference material prepared by Y. Xiao) Soufre de Lacq elemental sulfur (IAEA-S-4) is now again available, its isotopic homogeneity having been demonstrated; d34S = +16.90 per mill relative to VCDT. David Mrofka <david.mrofka@EMA To: [log in to unmask] IL.UCR.EDU> cc: Sent by: Stable Subject: Prism II Software and Organic Carbon Standard Isotope Geochemistry <[log in to unmask] UVM.EDU> 04/17/2004 03:19 AM Please respond to Stable Isotope Geochemistry I have two questions and would appreciate any advice... 1. We have a Prism II running the original DOS-based software and are interested in updated software that can run on a newer computer. I searched the archives but there has not been much on this since Y2K. Any advice on updated software and who to get it from? 2. We are also looking for bulk solid carbon to calibrate with NBS-22 and use as our lab std for organic carbon measurements. Of course we are looking for something with lighter delta carbon values (-25 to -35 ?)...any advice on suppliers? Thank you, David Mrofka Earth Sciences University of California Riverside