Representative sampling and the proper use of reference materials

An edited transcript of the plenary discussion on the title subject is given. Some of the questions and topics are summarized in the following: The criteria for the choice of representative samples in environmental investigations. Is it possible to separate the sampling from the analysis. When sampling liquids compromises must be made. The analyst must by acutely aware of the limits of detection when sampling for analyses of trace elements. The size of the sample must be related to the degree of inhomogeneity encountered. When grinding up a sample not only details are washed out but the risk of releasing and loosing some of the volatile elements or adding impurities to the sample during the operations must be taken into consideration. (T.G.)