Skip main navigation

Talk with the expert : Prof. Medana on chemical analysis and safety

A video interview with prof. Claudio Medana, an expert in chemical analyses.
Thanks Dr. Medana for accepting this interview.  Could you describe the standard approach to   examine chemicals migrating from package ?  What are the times and costs of such analyses ? There are lots of different analytical chemistry  controls requested by laws and by quality control   procedures. Much depends on what we are searching.  One thing is measuring sodium in mineral water   or vitamin C in oranges – this is quite simple. In this course we are talking about chemicals   migrating from packaging, or from the external  environment in general, into food. In this case,   a typical analysis starts with exposing packaging  material of interest to extreme conditions, for   example by soaking it in solvent (called simulant)  from hours to days at high temperatures.
In the   end, the simulant liquid is collected and analyzed  for global migration with dedicated techniques.  A totally new test on a new material  may require week of work, high expenses  
(uncommon chemical determinations require   thousand of euros in order to set up the  analytical process) and highly skilled operators.   On the contrary, routine quality control analyses  may be cheap (< 10 euros) and easy to be obtained.
Dr. Medana, do you mostly perform tests on-demand   or do you also run investigations on  molecules, their origin, their transformation,   their toxicity, etc…? Do you also study the effect  of mixtures and kinetics in different conditions ?
Thanks for the question; this allows  me to say: we are not simply measurers.  I mean…Yes we do measuring…but analytical  chemistry is a border science which blends   chemistry, biology, pharmacology  and toxicology. Every analytical   department that I know collaborates with  biologists, pharmacologist and so on … 
A lot of new professionals are now available:  biological chemists, chemical toxicologists,   pharmaceutical chemists, clinical analysts  and so on. Science is nowadays a question   of collaboration and peer to peer share  of information, no-one works on his own.  It’s absolutely normal for a chemist to perform  the analysis of a mixture of potentially active   substances in function of relative presence or to  evaluate the evolution of a transforming molecule,   during its trip inside a living body. For  example, a scientist that studies toxico-dynamics   is interested in the effects for an organism;  another one studying toxico-kinetics   looks at the effects that the organism has  on the chemical, modifying its structure. Very well.
Can you make an  example of an investigation   started in your lab or one  from an external customer ? Sure. my lab was involved in a determination of  plasticizers in the blood of lactating mothers and   their babies. We searched for some molecules whose  presence is not allowed in plastic containers,   pacifiers and kitchenware for babies. As we  expected, no residue of the banned chemicals   was found in samples from healthy women and their  children. On the contrary, and a bit worrying,   some hospitalized mothers show the presence of the  plasticizers owing to the use of plastic bags and   syringes for intravenous therapy in  which these chemicals are still used.
Mmh, changing subject : chemical language  is somehow difficult to common people,   with strange names and terminologies  … Technical communication has little   efficiency. So, how can results be  expressed to be easily understood ? Neil, you are right. Scientific names and  terms (polybutylene adipate terephtalate,   hydroxymethyl-carbamide chloride salt ..  two example of bizarre names ..) are far   from everyday language. But this is the language  that chemists need to use, becuse is very precise.   The “colloquial” names for us is not  sufficient. But I understand that this   language does not translate to most people.  Communication is a big issue, and you will   see much about this in week 5 of this course. If we simplify … we inevitably loose something. 
Example: if I tell you: “the sample I have tested  has a release of plastic material derived from   packaging of 4 mg/kg” this is not very informative  unless I also tell you what is the range   of harmful concentration. It would be simpler  that I tell you “this is not safe”. Period.  But this statement is now relative and  two scientists may call the same result   as good or bad, depending on their  points of view or their reference data.  My firm idea is that ethical guidance should be  more important than scientific popularization,   like in other fields. Am I speaking too  difficult now ? Mhh I’m a scientist…
Finally, is there a message you  want to leave to our students ? Yes thanks. I’d like to make the point  about some analytical tests that seems   too expensive, tiresome and therefore  unjustified and a waste of time.  I like to remember the saying “By failing  to prepare, you are preparing to fail.”

In this video interview you will listen to Prof. Claudio Medana, from the University of Torino, to explain and discuss how chemical analyses are used to reveal the presence of unwanted chemicals. Prof. Medana is the leader of an active laboratory strongly involved in these analyses. Don’t miss this great interview.

This article is from the free online

Consumer and Environmental Safety: Food Packaging and Kitchenware

Created by
FutureLearn - Learning For Life

Our purpose is to transform access to education.

We offer a diverse selection of courses from leading universities and cultural institutions from around the world. These are delivered one step at a time, and are accessible on mobile, tablet and desktop, so you can fit learning around your life.

We believe learning should be an enjoyable, social experience, so our courses offer the opportunity to discuss what you’re learning with others as you go, helping you make fresh discoveries and form new ideas.
You can unlock new opportunities with unlimited access to hundreds of online short courses for a year by subscribing to our Unlimited package. Build your knowledge with top universities and organisations.

Learn more about how FutureLearn is transforming access to education