If pyrene is the only source of DCM extracts, the pyrene material balance in run 11 would increase to 22 x 1.
Table 3 shows no pyrene or extractables in the residue, implying that pyrene was completely removed from the heating boat, presumably by evaporation, at all four temperatures.
FA formation by isomerization of pyrene (MW 202) is unlikely in light of the high activation energy needed to form a 5-membered ring from a 6-membered ring, and in light of Scott and Roelofs' (29) report of FA equilibrium with two other 5-membered ring PAHs, acephenanthrylene and acenanthrylene, but not pyrene, in experimental studies of FA pyrolysis at 920, 1,000, and 1,115 [degrees] C.
16) detected the latter class of compounds from pyrene pyrolysis and attributed their formation to dimerization and cyclodehydrogenation of different bipyrenyls.
As discussed above, the pyrene recoveries fall within a factor of 2, directly at 250, 500, and 750 [degrees] C, and after correcting for the CF collection efficiency at 1,000 [degrees] C (Table 3).
The pyrene material balances at all four temperatures are discussed above, including factors (CF blow-by, pyrene conversion to other products) that could account for the appreciable pyrene shortfalls (Table 3) at 750 and 1,000 [degrees] C.
Other than pyrene, a class of PAHs designated pyrene derivatives were the only PAHs detected in the soil residue and CF extracts at 250 and 500 [degrees] C (Table 2).
Benzo[a] pyrene (BaP) and/or CPP were detected in CF extracts from pyrene, sand plus pyrene, and soil plus pyrene at 750 and/or 1,000 [degrees] C (Tables 2, 4, 5).
Temperature ([+or-] 20 [degrees] C) Material(b) 500 750 1,000 [degrees] C [degrees] C [degrees] C Pyrene ND ND 0.
c)The real value is lower due to coelution of a pyrene derivative with CPP.
Woburn, MA) tested DCM CF extracts from 500 [degrees] C and 1,000 [degrees] C heating of pyrene, pyrene plus sand, and pyrene plus soil, and the DCM extract of the residue from heating uncontaminated soil at 250 [degrees] C in vitro for mutagenic activity at the thymidine kinase locus in hlAlv2 human diploid lymphoblasts using a 72-hr exposure.
Temperature Extract Sample Description [+or-] 20 [degrees] C tested 2 Pyrene 500 CF 4 Pyrene 1,000 CF 5 Uncontaminated soil 250 Residue 10 Soil + pyrene 500 CF 12 Soil + pyrene 1,000 CF 14 Sand + pyrene 500 CF 16 Sand + pyrene 1,000 CF Concentrations Smallest tested concentration Sample Description (g/mL) with mutagenic effect (g/mL) 2 Pyrene 0.