J. Shiowatana et al., A flow system for the determination of metal speciation in soil by sequential extraction, ENVIRON INT, 26(5-6), 2001, pp. 381-387
A flow extraction system with on-line acid off-line flame atomic absorption
spectrometric (FAAS) detection was developed to speed up, facilitate. and
improve the accuracy of sequential extraction for metal speciation in solid
materials. A flow extraction system with off-line detection was more advan
tageous than the on-line detection. In the proposed system, extraction was
performed in a closed extraction chamber where extractants were newing thro
ugh sequentially. The extract from each extraction was collected in 4-10 fr
actions to obtain a total of approximately 180 ml for subsequent FAAS deter
mination. The system is simple, easy to construct and operate. It has less
risk of contamination and human error. A widely used three-step sequential
extraction scheme was used to evaluate the novel system by analyzing Ca, Fe
. Mn, Cu, and Zn in a certified reference material. The extraction time for
three-step sequential extraction of soil sample was 4 h. The analytical re
sults for Ca, Fe, Mn, Cu, and Zn of a soil certified reference material usi
ng the proposed system were compared with those of the conventional batch e
xtraction. (C) 2001 Elsevier Science Ltd. All rights reserved.