Internal standard based calibration plots were used for quantifi-
cation. The HHCB, AHTN, TCS and DPH were consistently observed with concentration of 0.163–0.892,
0.068–0.904, 0.189–1.182, and 0.942–7.472 ng g1
, respectively. These values are at least 1–3 orders of
magnitude lower than those obtained in environmental fish specimens. The MK was not detected in
any fish.