Determination of PCDD/Fs and dioxin-like PCBs in fish oils for feed ingredients by congener-specific chemical analysis and CALUX bioassay.
The present research was intended to determine the suitability of the CALUX assay as a screening method for dioxins in fish oil used as a feed ingredient in Japan. Alteration of TEQ in fish oil according to newly proposed toxic equivalency factors (TEF) is also discussed. In the analysis, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in 41 fish oil samples were determined by using high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) and CALUX bioassay. The mean TEQ values derived from 1998 WHO-TEF of PCDD/Fs and DL-PCBs were 2.6 and 9.9 pg g(-1) (ww), respectively. The levels of TEQ derived from the recently re-evaluated 2005 WHO-TEF were slightly lower than those of the former in both groups. Notably, the contribution of mono-ortho DL-PCBs to total 2005 WHO-TEQ was considerably decreased compared to the case of 1998 WHO-TEQ, resulting from the reduction in its TEF values, while the non-ortho DL-PCBs contribution was increased. The mean TEQ determined by CALUX assay for PCDD/Fs was approximately three times higher, whereas DL-PCBs was approximately two times lower than WHO-TEQ determined by HRGC/HRMS; the sum of PCDD/Fs and DL-PCBs was very similar by both methods. The correlation coefficients of TEQ between the CALUX assay and HRGC/HRMS analysis were 0.84, 0.89, and 0.90 for PCDD/Fs, DL-PCBs, and the sum, respectively. These results suggest that the CALUX assay is a very useful method for the screening of dioxin-related compounds in fish oils.
Hasegawa
Jun
J
Safety Research Team, National Institute of Animal Health, Kannondai 3-1-5, Tsukuba, Ibaraki 305-0856, Japan.
Guruge
Keerthi S
KS
Seike
Nobuyasu
N
Shirai
Yuji
Y
Yamata
Toshiaki
T
Nakamura
Masafumi
M
Handa
Hiroshi
H
Yamanaka
Noriko
N
Miyazaki
Shigeru
S
D000821:Animal Feed; D001681:Biological Assay / Q000379:methods*; D004784:Environmental Monitoring / Q000379:methods*; D005395:Fish Oils / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D007564:Japan; D008156:Luciferases / Q000032:analysis; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis
D005395:Fish Oils; D000072317:Polychlorinated Dibenzodioxins; D011078:Polychlorinated Biphenyls; D008156:Luciferases