Sample preparation (cleaning, drying, homogenization) for trace element analysis in plant matrices

In the process of instrumental element analysis of plant samples, cleaning, drying and homogenization of the collected material are steps that constitute a very great potential source of error. One of the reasons for this is the difficulty of standardizing the procedure. A major obstacle to consistent quality control is the multitude of different plant species and their division into leaves, shoots and roots. The resulting morphological and physiological heterogeneity of the samples makes it necessary to plan and carry out each of these analytical steps in a highly specific manner according to the individual plant species. The extraordinary diversity of the sample material makes it impossible to establish a generally valid method. This paper describes and discusses various approaches to cleaning, drying and grinding such samples.