Hello, 

I was trying to find information online about whether or not isopropyl alcohol has any fluorescent properties but haven't had much luck. From what I can tell, it seems not to. However, I have encountered an issue where I am using a fluorometer to measure aflatoxin levels and I noticed yesterday that all of my results were coming out unusually high. So today before I did some re-tests, I did a blank check of my solvents and my cleaning supplies, and the alcohol that I use for disinfecting (70% IPA) has been giving me pretty high readings. I find it hard to believe that the alcohol is actually contaminated with aflatoxins so I'm just wondering if there is something in the alcohol that is causing it to fluoresce or if I am just missing something here. 

 

Thanks!

Simple alcohols like isopropanol will not fluoresce in the accessible bits of the spectrum.

However, lots of other things will. If you rinse your fingers in IPA you will probably get a solution that fluoresces somewhere in the UV.
Washing powders are other massively bright fluorophors. It's probably not an aflatoxin   impurity that's causing the problem, but it could be  almost anything.Disinfectants may contain things like quaternary ammonium compounds which will fluoresce.

https://en.wikipedia.org/wiki/Benzalkonium_chloride

 

 

 

 

Many years ago now people in my research group did florescence experiments. We used IPA all the time for stuff. If there was an issue I'm sure they would have noticed. 

 

Edit:crosspost with John. 

Intuitively I would think that you may have some contaminants. IPA is a commonly used solvents for many fluorescence-related analytics and is commonly used in the UV range due to its low absorbance.

Ah, thank you all for your feedback. I'm probably just going to discard all of the bottles that were already open and hope this doesn't become an ongoing problem. 

On 27.10.2017 at 10:22 PM, skhan27 said:

I'm probably just going to discard all of the bottles that were already open and hope this doesn't become an ongoing problem. 

Distill them, and try again whether you have the same results..