2. Total content analysis

2.1 Sampling. Storage

• Sampling is a key stage in the analytical process, and one that is all too often neglected. In fact, few laboratories are capable of good sampling. The problem to be solved is that of sample representativeness. What is primarily a statistical problem takes on an additional analytical aspect in trace analysis. Indeed, the distribution of trace elements is more likely to be heterogeneous than that of major elements. The sampling method chosen therefore depends on the question to be answered.

  Two examples illustrate the complexity of such an operation.

  In water, the concentration of trace elements varies with depth, salinity, proximity to discharge points, etc. A study of such an environment...