Which simulant can i use to replace n-heptane in Migration Testing of Plastics? Not olive oil but any organic solvent? N-heptane is not easily available so I am looking for a replacement.
Dear Shruti Sharma
you can find some answer in the attached file and in the below reported link:
http://onlinelibrary.wiley.com/doi/10.1111/1541-4337.12028/full
The substitute for olive oil is typically isooctane.
What are you interested in, total migration, or are you doing GC-MS after your leaching/migration experiment?
Depending on what you are interested in and what polymers you are analysing, any solvent might be suitable. You should match the polarity of polymer-analytes-solvents to answer your questions.
I don't understand why you say "stimulant" for n-heptane, a straight chain alkane of 7 carbons. If you mean "solvent", n-hexane (6 carbons) is slightly more volatile than n-heptane. Isooctane (8 carbons with methyl branching) is slightly less volatile, and should work just fine as a solvent for plastics monomers and many other paints. Plus your car will run very well on this fuel.
I am working on Total migration in plastics so, I follow the gravimetric method.
David I'm sorry for the typo, I intended to write 'simulant'. Besides, what do you think would be the reason for international standards for strongly recommending only n-heptane for plastic migration testing?
I would think because it should be pretty cheap...it is just a gasoline fraction like n-hexane. Gravimetrical analysi- if the same solvent is used by everyone, the data gets much more reproduceable. I assume you grind up or cut up your plastic material, extract it in a Sohxlet extractor with a condenser at the top. Then after period of time X, filter off the so;lvent and reduce it to dryness = plasticizer residue. So what happens if you use the n-heptane on a series of plastic materials, then use n-hexane in comparison. Plot a chart. See if there is a reproduceable comparison. The results may be nearly identical, or within the range of error expected by physical weighing.
Mnay years ago, with limited US Department of Africulture funding being cut by President Nixon, I could not afford to buy commercial analytical grade n-hexane for my insect extracts ($20/liter) to analyze cutucular hydrocarbons. But I could buy an entire barrel of hexane for $45 then wash, dry and and distil my own for the same price. So I did so for many years.
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