Neutron activation analysis (NAA) in service of other analyses

NAA has a more mundane role to play than usually presented: as one tool in the analytical chemistry toolbox from which a selection can be made based on appropriateness and convenience rather than on sensitivity. The advantages of NAA are well established. This paper illustrates this with a few examples: (a) Bone fragments were analyzed for calcium to provide standardization for in vivo density measurements by gamma ray absorption, (b) elemental levels were determined in bone and tooth fragments in modern and ancient specimens in conjunction with determination of lead by isotope dilution mass spectrometry to allow estimates of the diagenetic absorption of lead by the ancient samples, (c) an ongoing study measures bone calcium loss as a result of prolonged radiation exposure in beagles, (d) 16O/18O ratios were measured in studies on isotopic exchange reactions. The methods developed sufficient precision only to justify the conclusions needed. For example, in one study it proved more important to get an estimate for the calcium content of an irregular shaped bone fragment, whereas in another, the experiment justified reducing fragments to homogenized pellets of reproducible geometry