Choice of the best multi-element package for rock analysis or soil analysis depends on the information that needs to be obtained. ICP-MS packages are the broadest (60+elements) and have the lowest detection limits. ICP-OES (35+ element) packages are usually the lowest cost, but have higher detection limits. INAA packages can be purely instrumental with no chemistry and are therefore very reliable. There are also a variety of multi-method analytical packages to provide the best data for different elements by the best available technique. Choice of which package is best for you has to be determined by “fitness for purpose”. Choice of digestion method is critical in trying to interpret the resulting data.