Of the 200 feed samples, 84 were positive for AFB1 with the
concentrations at the range of 0.05e3.53 mg/kg, along with the
mean and the median values of 0.31 mg/kg and 0.15 mg/kg, respectively.
Among them, 27 samples contained AFB1 in the range of
0.01e0.10 mg/kg, and 53 samples had the AFB1 concentrations between
0.01 mg/kg and 1.00 mg/kg. Four samples, including one
sample from Tianjin, two samples from Heibei province and one
sample from Guangdong province had the AFB1 concentrations in
the range of 1.01e4.00 mg/kg (Table 3). No sample from Heilongjiang
province was tested positive, and Shandong province had
the highest incidence of positive samples at 75%. For 160 samples
from the north of the country, the incidence of AFB1 was 41.9%,
with a maximum of 3.53 mg/kg, a mean of 0.30 mg/kg and a median
of 0.15 mg/kg. For 40 samples from the south of the country, the
incidence of AFB1 was 42.5%, with a maximum of 1.45 mg/kg, a
mean of 0.33 mg/kg and a median of 0.16 mg/kg. There was no difference
observed between the north and the south in the contents
of AFB1