Evaluation of extraction procedures for the ion chromatographic determination of arsenic species in plant materials

The determination of arsenic species in plants grown on contaminated sedime nts and soils is important in order to understand the uptake, transfer and accumulation processes of arsenic. For the separation and detection of arse nic species, hyphenated techniques can be applied successfully in many case s. A lack of investigations exists in the handling (e.g., sampling, pre-tre atment and extraction) of redox- and chemically labile arsenic species prio r to analysis. This paper presents an application of pressurized liquid ext raction (PLE) using water as the solvent for the effective extraction of ar senic species from freshly harvested plants. The method was optimized with respect to extraction time, number of extraction steps and temperature. The thermal stability of the inorganic and organic arsenic species under PLE c onditions (60-180 degrees C) was tested. The adaptation of the proposed ext raction method to freeze-dried, fine-grained material was limited because o f the insufficient reproducibility in some cases. (C) 2000 Elsevier Science B.V. All rights reserved.