Lipid-soluble arsenic species identified in the brain of the marine fish skipjack tuna () using a sequential extraction and HPLC/mass spectrometry

• Published in: Journal of analytical atomic spectrometry Vol. 34; no. 12; pp. 244 - 245
• Main Authors: Stiboller, Michael, Freitas, Fabiana P, Francesconi, Kevin A, Schwerdtle, Tanja, Nogueira, António J. A, Raber, Georg
• Format: Journal Article
• Language: English
• Published: London Royal Society of Chemistry 01.12.2019
• Subjects: Arsenic; Bicarbonates; Brain; Fish; Lipids; Mass spectrometry; Muscles; Propionic acid; Scientific imaging; Spectroscopy; Tuna; Water chemistry
• ISSN: 0267-9477; 1364-5544
• DOI: 10.1039/c9ja00249a

Lipid-soluble arsenicals, so called arsenolipids, occur in appreciable quantities in various marine organisms including fish. In this study, arsenolipids as well water-soluble arsenic species were investigated in brain (9.1-17.4 mg As per kg; dry mass) and muscle (4.0-5.8 mg As per kg; dry mass) tissues in five specimens of the marine fish skipjack tuna ( Katsuwonus pelamis ). For this purpose, we developed a sequential extraction method whereby the freeze-dried tissue was first treated with pyridine (organic extract) followed by aqueous ammonium bicarbonate (water extract) to extract arsenolipids and water-soluble species, respectively. When the method was applied to the tuna tissues, the arsenic distribution for brain was 55% (organic extract), 30% (water extract) and 15% (pellet), whereas for muscle tissue the corresponding values were 20%, 55%, and 25%. Arsenic species in water and organic extracts of muscle and brain tissues were investigated by HPLC/mass spectrometry. For both tissues, the water extracts contained arsenobetaine as the major arsenic species together with small amounts of dimethylarsinate and trimethylarsine oxide; trace amounts of dimethylarsinoyl propionic acid were found only in brain tissues. Arsenic-containing hydrocarbons (AsHCs), were the major arsenolipids in both tuna brain and muscle. The arsenolipid content in brain ranged from 3.8-5.9 mg As per kg, whereas it was substantially lower in muscle (0.3-0.8 mg As per kg) reflecting arsenolipids' potential to cross the blood brain barrier and accumulate in the fish brain. Arsenolipids detected in the brain of the marine fish skipjack tuna ( Katsuwonus pelamis ) using HPLC/mass spectrometry.