food_knowledge_012521I have recently been exploring the world of home buying and have come to the realization that there is much more to it than I expected. I thought my friends were getting way too stressed out about finding that “forever” or “for right now” home. As I started to contemplate taking the plunge myself, I began to realize that there is a lot more to consider beyond a pretty facade. Determining what lies below the surface is just as critical, if not more so, than making sure the paint is not peeling off the walls. Fortunately, with houses, there are various inspections that are done as part of the purchase process and one of the most critical is the pest inspection. While a house may look sturdy from the outside, if some form of pestilence is found, the specific type present can have major structural implications. It could either require minor surface treatment to fix or extensive invasive surgery. It certainly pays off to take the extra steps to determine any potential threats to a house’s foundation and the same can be said when it comes to investigations into the food that you eat. Knowing a food’s composition, both nutritive and toxic, will confirm its safety and give those who supply our food insight into what processing strategies might be the most effective to deliver healthy products.

One way in which consumers can choose healthy options is to read the label, but the information contained is limited, usually giving total amounts of broad ingredient categories as a percentage of the daily recommended intake. Information regarding potentially harmful or toxic compounds is normally not given on the label, and consumers can safely rely on government regulations to establish limits and food processors to devise methods to either remove or reduce the levels of these compounds to an acceptable amount. One high profile example is arsenic. While inorganic arsenic is highly toxic and carcinogenic, organic forms are far less toxic (e.g. dimethylarsenic acid (DMA)), with some being considered non-toxic (e.g. arsenobetaine; AN43255). Another is iodine, which is present in seaweed, a food that has gained in popularity because of the relatively low impact on the environment of its production growing in seawater of which we have in abundance [1]. In contrast to animal-based foods, it does not need the high-intensity farming required to produce cereals for feed, with the associated high energy costs from the use of fossil fuels and resulting emissions that contribute to global warming, and runoff of fertilizers into local water sources causing algal blooms. Seaweed is high in protein, vitamins, fiber, fatty-acids and rich in minerals such as sodium (not too surprising considering it grows in seawater) and iodine, with some species having up to 8 g/kg dry weight of the latter. While iodine is an essential nutrient, it can cause thyroid disorders if consumed in excess [2].  One way of reducing iodine content in seaweed is by processing it so that it is removed [3]. One of the challenges with this is that the effectiveness of this process can vary depending upon the specific elemental species present. Iodine can be in inorganic (iodide, iodate) and organic forms (predominantly 3-iodo-L-tyrosine (monoiodotyrosine, MIT) and 3,5-diiodo-L-tyrosine dihydrate (DIT)). Inorganic iodine is more easily extracted than organic forms, which may require extensive digestion for iodine release. Knowing the species present can aid the development of food processing strategies to reduce the amount of iodine present thereby reducing the risk of excessive intake from high seaweed consumption.  A recently published application note describes the use of a hyphenated IC-ICP-MS system, combining a Thermo Scientific™ Dionex™ ICS-6000 HPIC™ system with a Thermo Scientific™ iCAP™ TQ ICP-MS (Inductively coupled plasma mass spectrometry) to determine iodine-containing species in seaweed. Following sample preparation to release the iodine into solution, samples were filtered and then subjected to chromatographic separation followed by ICP-MS detection that was tuned to the specific mass of iodine. Anion-exchange chromatography using Reagent-Free IC (RFIC) was optimized to determine three iodine species (MIT, DIT, and iodide) in under 13 minutes. Limits of detection were in the parts per trillion (PPT) range and the ratios of inorganic to organic ranged from <1% to ~ 30%, depending on the seaweed species. Variability in the recovery of total iodine from each seaweed suggested that the specific method used can impact extraction and alternatives should be explored if further reduction in the final product is required.

Like what you are learning?

Sign up to stay connected with all Thermo Scientific resources, applications, blog posts and promotions.
Keep Me Informed!

Just as it is best to determine what is below the surface when considering a home purchase, speciation lets you dive deeper into the elemental content of foods to get a truer indication of their nutrition and the steps that might need to be taken to deliver a healthier product to consumers.  Please visit to find more information and applications of speciation analysis to assure healthy food and a clean and safe environment.