The human body is an amazing feat of engineering crafted by natural selection’s potter’s wheel. The biochemical processes and resultant emergent physiology, allows us to thrive on a hostile planet. Our skin protects us from the sun’s deadly ionising rays , our internal biochemistry has allowed us to harness the oxidising and free radial-forming properties of highly toxic atmospheric oxygen. Our DNA repair processes continually act to correct errors in our genetic blueprint responding to both internal forces and external pressures, such as ionisation damage caused by environmental background radioactivity. Our immune systems continually defend us against external threats, like viruses and bacteria, as well as regularly destroying the daily emerging cancerous cells before they take hold.
Furthermore, we are able to unlock and exploit a rich pallet of nutrients from an unfathomable number of food sources and in some cases, detoxifying unwanted poisonous components. Over the millennia, natural selection has shaped us (and organisms around us) to thrive in the continual shifting sands of our external environment. In short, our internal environments can protect us and allow us to thrive in our potentially dangerous and toxic environment.
While natural selection is remarkable, it is also a slow and gradual process. It requires many generations for organisms to adapt to a change in their environment allowing continual survival. Our current understanding suggests that human beings are the only organisms to have achieved self-awareness, developed complex languages & thought processes, and, in doing so, created complex tools to continually exploit our environment for resources. The result of this is that we have super charged our rapid development, which has allowed us to be where we are today. However, in doing so, we have massively outpaced natural selection. This is means that we are exposing ourselves to manmade hazards and toxins, such as PFAS, as well as unlocking natural hazards which have been kept safe through natural geological barriers.
There are specific moments in human history that have accelerated the development of humankind, such as the exploitation of fire for cooking and heating by early humans, for example. Moreover, in relatively recent times, it was the discovery, drilling and processing of mineral oil, gas and coal which drove the industrial revolution at the turn of the 20th century. This not only provided what seemed, at the time, to be a limitless supply of
energy, but also enabled the creation of the modern industrialised world we know today. Also, the biproducts of the processing of mineral oils has led to creation of a plethora of exotic polymer-based materials which has underlined much of the fabric of our modern societies for decades. For example, as I sit writing this blog, I’m typing on a plastic keyboard, staring at a monitor with a plastic screen, sitting on a plastic-coated chair, using a plastic mouse on a polyester and foam mouse pad and working in a white-walled office painted with a polymer containing paint. All created with products manufactured from the oil industry. In short, the products of mineral oil exploitation are everywhere and so need to be monitored as they potentially pose health risks.
One reason why this is the case is that the biomass from dead organisms have undergone many biological and chemical changes over the millions of years in the ground. For example, over time, natural oils and fats from long dead organisms will form new and unique chemical structures which then make up many of the components of what we call mineral oil. If left unchecked, over millions of years, much of this would eventually move down into the earth’s mantle to be released back into our atmosphere as CO2 from volcanic activity. In other words, these products are normally safely locked away in the earth (out of harm’s way) and naturally removed by geological activity. However, our recent exploitation of ‘liquid gold’ has disrupted the natural process, risking exposure of an unfathomable variety of unique oil products into our current environment. The main issue is that we have not evolved to physiologically process these, and so if consumed, many are toxic and some are also thought to be carcinogenic. Therefore, if these products enter our food chains, these present a clear and present danger to public health.
Mineral oil hydrocarbons or MOHs are classified into two groups. The first are mineral oil saturated hydrocarbons (MOSH) which are generally consist of n-alkanes, branched alkanes, and naphthenic, i.e. cyclic, compounds. The second group are mineral oil aromatic hydrocarbons aromatic hydrocarbons(MOAH), whose arrangements can range from highly alkylated aromatics (mostly 1 to 2 ring systems) up to 3 to 7 ring systems. Mineral oils can unintentionally enter foodstuffs via a variety of pathways. One important pathway is the transfer from printing inks to food packaging made of paper, cardboard, and paperboard. Other sources include, lubricants in machinery used in harvesting or food production, processing aids, food additives, and food contact materials.
Control of MOSH MOAH components is increasingly coming into focus, particularly within the EU and for companies importing food substances into Europe. For an overview of the evolving regulatory landscape around control of MOHs, the reader is recommended to review section two of a recent white paper authored by Trajan.
Food substances are complex and varied, some are raw materials like edible oils, others are processed-substances such as infant formula. Identifying and quantifying mineral contamination within foods is no mean feat. The reason is that the sheer number of components in MOHs (literally thousands) make analytical specificity highly challenging. This is especially the case when the physicochemical properties of contaminants are similar to naturally occurring fats and oil and their biogenic products in food. As a result, a different approach needs to be taken to identify and quantify contamination when compared to, for example, identifying a specific contaminant like the carcinogenic monochloropropane-1,2-diols or MCPDs. In this example and others like it, MCPDs can be identified and quantified as single peaks on a GC-MS instrument. However, even with our recent advanced technologies, reliably measuring all the components in MOHs is not practical and probably unnecessary to detect their presence. Instead, the preferred method for measuring MOHs is to essentially create two fractions the first being MOSH components and the second the MOAH components. Once these are isolated then these individual fractions are identified and quantified, not as individual peaks but instead as regions on analytical chromatograms, which resemble ‘humps’, each containing a multitude of components. These are known as Unresolved Complex Mixtures (UCM).
Due to their relatively low volatilities, oils and oil components are measured using gas chromatography (GC). Like all chromatographic analytical methodologies, the sample needs to be introduced to the instrument having first undergone some degree of sample clean-up. The reason for this is that chromatographic columns can be easily contaminated both physically and chemically. Physical contamination occurs, when insoluble contaminants in the sample are inadvertently injected onto columns causing blockages. Chemical contamination often involves soluble components which adhere to the chromatography. Another form of contamination is when a component of the sample chemically changes the analytical column such as for example a derivatising agent. Both forms of contamination risk changes to the column chemistry risking the analytical performance and reliability - as well as impacting overall column lifetimes. It can be argued that GC instruments have liners which act to trap non-volatile components before they are introduced onto the column. However, these should only act as a final level of column protection and so prior sample cleanup is often essential. As a side note, Trajan manufactures industry standard GC columns and state of the art liners designed for greater longevity of both liner and column lifetime. For more information click here
Due to the varied complex nature of food matrices, the sample preparation for MOSH MOAH analyses, is rather involved and at a minimum requires, a normal phase (NP) HPLC fractionation prior to GC analysis. Moreover, there are also occasions where initial clean-up prior to the NP LC is also required. Therefore, in this blog series, we will investigate the science behind these approaches and how Trajan has successfully incorporated these into fully automated workflows and used by many food safety companies globally.