Batches are divided into groups of 8 unknowns. Each group is irradiated with a standard, and the cost of preparing, irradiating, and counting the standard is charged. Blanks are also charged for but, like duplicate samples, blanks are a wise investment when considering accuracy and reproducibility of results. Elements with activation products having similar half lives can often be analyzed simultaneously. The element lists are divided into for short, intermediate, and long-lived activation product half life.
Some elements appear in more than one list.
Yb Zn Analysis for each element list will require a different irradiation, decay, and counting time. Analysis with emphasis placed on a particular element or group of elements may preclude other elements on the same list. Interferences may occur in some samples. If an analysis requires determination of elements in one of the tables only, one irradiation and one count would usually be required. If the analysis required one element from Table 1 and all the remaining elements were from Table 3, two separate irradiations and two counts would be required.