“It is only recently that such compounds have been identified,” said Jens Sloth, senior scientist, Denmark Technical University (DTU), who has developed a new EU standard method for determination of the essential element, iodine, in feed and is in the process of doing the same to determine the concentration level of inorganic arsenic.
Sloth presented at the feed safety conference Feed2016 in Belgium in late October, where he discusssed his analytical work and the concerns in the scientific community around the lack of existing data on arsenolipids. We caught up with him this week to hear more.
He said a very recent study indicated that some arsenolipids (called arsenohydrocarbons) exert a cytotoxicity comparable to inorganic arsenic, a well-known carcinogen.
Those findings, said Sloth, indicated that more research, including both in vitro and in vivo trials, was required to achieve a better understanding of the occurrence, origin and health implications of these compounds in order to ensure food and feed safety.
Iodine levels in feed
Meanwhile, the EU standard iodine analytical method, based on plasma mass spectrometry (ICP-MS), that Sloth and his colleagues developed, is due to be published in 2018:
“Until now. there was no such standardized methods for iodine determination in feed, only one validated for food matrices.
“The method has been tested extensively in 14 laboratories and discussed and evaluated in a CEN expert working group. It awaits formal approval, which is expected during 2017,” said Sloth.
As per the European Committee for Standardization (CEN) guidelines, he chose experienced laboratories - in Germany, the Netherlands, Ireland, Austria and in the Czech Republic - to trial the method. Sloth said it was successfully tested in a broad concentration range of 0,70 to 631 mg/kg in feeds such as seaweed meal, a mineral premixture, fishmeal, a plant based ingredient and a marine based compound feed. "The method will be used for the future control [as per EU maximum levels] of iodine in animal feeds," he said.
Inorganic arsenic in feed
The researcher is also developing a EU standard analytical method to detect inorganic arsenic, classified as a carcinogenic for humans by international panels, in feed, following on from a EU Commission directive.
He said it is generally known what type of feedstuffs contain inorganic arsenic – typically certain types of seaweed, mineral premixures – but the Commission requested an updated analytical approach for inorganic arsenic as the existing methodology is based on older technology that some laboratories no longer have access to.
“My plan is to have testing in recognized labs in 2017, the results fed back and technical approval in 2018, with the standard likely published in 2019,” said Sloth.