Relative aquatic concentrations RAC

Fig. 5 Scheme of model for calculating relative aquatic concentrations (RAC). The soil compartment and the river model are connected through the flux (fsw) from soil to the first box of the river model. The river model consists of flowing water (shaded boxes), stagnant water (white boxes) and an underlying river sediment (not shown). Reprinted with permission from [8], p 2446. (2007) American Chemical Society... 

For calculating the toxic potential of each metabolite TPi and of the mixture of parent compound and metabolites, TPmixture (Eq. 1), the relative fractions /] of each transformation product need to be known. As described earlier we used the relative aquatic concentrations (RAC) calculated by Gasser et al. [41]. These data were used here after rescaling to fractions. The resulting fi are depicted in Fig. 5, left column. Approx. 50% of diuron is still present as parent compound after metabolism while DCPMU and MCPDMU are quantitatively the most relevant transformation products, both contributing approx. 20% of fi to the total mixture. The RPparent by... 

Fig. 6 Comparison of mf (steady-state mass in soU),/sw (flux from soil to water) and RAC (relative aquatic concentration) within the mesotrione substance family (MNBA 4-methylsulfonyl-2-nitrobenzoic acid, CHD cyclohexane-1,3-dione, AMBA 2-amino-4-methylsulfonylbenzoic acid). All values normalized to values of the parent compoimd. Reprinted with permission from [8], p 2448. (2007) American Chemical Society...

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