Kamen, Martin David, 1913-2005-10-052005-10-051946http://hdl.handle.net/2246/393p. 105-138 : ill. ; 27 cm.Includes bibliographical references (p. 133-138)."In this review, material on the separation and assay of isotopes is presented. All of the available evidence on isotope effects in the biosphere is collected and discussed. The reader will find that while on the one hand a large fund of data is available on the laboratory separation and assay of isotopes, there is a paucity of reliable data on geochemical isotope effects. This situation arises from the fact that only recently have assay methods methods reached the precision required for application to geochemistry. The special role of biological systems in affecting isotope separations still remains to be established. Preliminary data already reveal such effects for hydrogen, oxygen, and carbon, and perhaps potassium. It can hardly be doubted that careful systematic studies with the newer techniques available will contribute much more valuable data, as well as resolve anomalies and uncertainties now existing in the present data"--P. 132.11899248 bytesapplication/pdfen-USQH1 .A4 vol.87, art.2, 1946Biogeochemistry.Isotopes.Analytical geochemistry.text