Table 3 summarizes the concentrations of
six arsenic species, including inorganic arsenic [As(III) and As(V)],
common organoarsenic compounds found in the environment
(MMA and DMA), and organoarsenic feed additives (ASA and
ROX) in the environmental matrices of the CAFO zone. It should
be noted that the total amount of arsenic species extracted by
the 0.5 M H3PO4 is much less than the total arsenic in the soil
and sediment samples determined by total digestion. This is not
surprising, as inorganic arsenic is primarily present within the
matrices of soil and sediment minerals and this fraction is not
extractable by weak acids, while the results of total digestion
include this fraction (Zhang et al., 2012a).