current consistently, with only traces of isotopic fragmentation, and accurately estimated the Fm values. The GCIP produced by our optimized method13 consistently produced ∼115 µ A of 12C- and accurate and precise Fm value with a throughput of up to 270 AMS targets per skilled analyst/d for biological/biomedical AMS applications. ACKNOWLEDGMENT The authors thank the reviewers for their perceptive and helpful comments. The authors also thank Drs. Ted Ognibene and Bruce Buchholz at LLNL CAMS for AMS measurements. This work was supported by NIH DK-45939, DK-48307, and the USDA Regional Research W-143 from the California Agricultural Experi- ment Station. Raman spectra were made at the Spectral Imaging Facility of the NEAT-ORU, Chemistry Department, UCD sup- ported by NSF-MRI-DMR-0723118 and NSF-MRI-DMR 0421521, XRD spectra were made at MatSci/CF in Material Science Department, UCD, SEMs were made at Pathology Department, UCDMC, and FT-IR was made at Textile and Clothing Depart- ment, UCD. This work was performed in part under the auspices of the U.S. Department of Energy by the University of Californias Lawrence Livermore National Laboratory under Contract W-7405- Eng-48 and NIH National Center for Research Resources Grant RR13461. Received for review June 16, 2008. Accepted August 8, 2008. AC801228T Analytical Chemistry, Vol. 80, No. 20, October 15, 2008 7669