TABLE 1.
Speciation of water-soluble selenium compounds in the tissues of bluefin tuna and other animals based on LC-ICP-MS analysis
Contents of selenoneine, selenoproteins including GPx and selenoprotein P, and unidentified selenium compounds in the tissues of bluefin tuna, Pacific mackerel, tilapia, chicken, pig, and Japanese common squid are shown. 0.1 g of sample was homogenized with 5× water, and 20 μl of supernatant was injected to LC-ICP-MS after 2–200× dilution with mobile phase (0.1 m ammonium formate). Values are the mean ± S.D. of three individuals.
| Species and tissue | Selenoneine | Selenoproteinsa | Unidentified selenium compounds |
|---|---|---|---|
| nmol of Se/g | nmol of Se/g | nmol of Se/g | |
| Bluefin tuna, farm-raised | |||
| Blood | 430 ± 82 | 24 ± 6.1 | NDb |
| Spleen | 41 ± 16 | 14 ± 2.5 | 4.0 ± 1.5 |
| Hepatopancreas | 39 ± 7.5 | 28 ± 12 | 2.2 ± 0.6 |
| Heart | 15 ± 15 | 4.8 ± 2.3 | 1.5 ± 1.0 |
| Red muscle | 190 ± 8.0 | 4.5 ± 0.5 | 5.3 ± 1.7 |
| White muscle | 2.4 ± 0.3 | 1.4 ± 0.2 | 0.5 ± 0.1 |
| Bluefin tuna, wild | |||
| Blood | 83 ± 29 | 28 ± 6.5 | NDb |
| Pacific mackerel | |||
| Blood | 437 ± 159 | 56 ± 10 | NDb |
| Tilapia | |||
| Blood | 0.9 ± 0.6 | 6.8 ± 3.2 | 0.55 ± 0.36 |
| Chicken | |||
| Liver | 0.3 ± 0.1 | 6.7 ± 1.0 | NDb |
| Heart | NDb | 2.0 ± 0.4 | 1.8 ± 0.4 |
| Gizzard | NDb | 2.7 ± 0.5 | NDb |
| Pig | |||
| Liver | NDb | 8.0 ± 1.2 | 5.0 ± 1.1 |
| Kidney | 0.36 ± 0.1 | 3.3 ± 1.5 | NDb |
| Japanese common squid | |||
| Hepatopancreas | 9.3 ± 3.5 | 5.0 ± 1.1 | 7.0 ± 1.1 |
a Selenoproteins eluted near the void volume of the column were estimated using bovine GPx as the standard.
b ND, lower than detection limit at 0.25 nmol of Se/g.