FIG. 1.

Chromatogram of the purge-and-trap gas chromatographic separation of the volatile metal(loid) compounds in the headspace of incubated sewage sludge samples after 1 week at 37°C. The compounds were identified by boiling-point retention time correlation and by the mass charge ratio (m/z) of the respective metal(loid) determined by ICP-MS analysis. (A) Recording for Sb and Bi. (B) Chromatogram of the same sample but at a 50-fold-higher sensitivity recording for As, Se, Sn, Te, and Hg. The recordings of Sb and Bi were omitted for clarity. cps, counts per second.