Chromatography Forum

Hi,

currently we are using chloroform to perform extractions with ointments.
But chloroform is a carcinogenic, so we always should be carefull.
Now some person came up with the idea that dichloromethane is less harmfull.
After some searching on the web, I found very different information: sometimes it looks like dichloromethane is less harmfull, other sites suggest the opposit.

Someone has some insights?


Kind regards

Bart

Hi

basicly dichloromethane has less evidence of being cancergenetic and have higher allowed exposere limits when compared to chloroform. So basicly they seems to be on track.

But why not search for something without chlor atoms? Heptane?

Bart - exactly what analytes are you trying to extract? Since you posted in the HPLC part, I assume you will be later blowing off the chlorinated solvent, reconstituting in a different solvent such as ACN or methanol, then assaying by HPLC. Maybe you could extract directly using ACN, methanol, or THF and let the HPLC column do the work, that's what we do: faster, easier.

We are trying to extract some very water soluble APIs from an ointment.
The chloroform breaksdown the ointment, and through liquid-liquid extraction we get a perfect recovery of our spiked samples.

But if dichloromethane is less carcinogenic we should think about this.
(Thanks for the suggestion of heptane, should also give that a try)

Thanks

Bart

The best reference for cancinogens is the regularly-updated "Report on Carcinogens " from the National Toxicity Programme of the Dept of Health and Human Services. The latest edition (11th) is available at
http://ntp.niehs.nih.gov/

You will see both Dichloromethane and Chloroform are considered as have similar concerns "reasonably anticipated to be a human carcinogen".

I would keep with what works, if you know the hazard you can mitigate the risks. However, if you organisation has a policy on replacing suspected human carcinogens, then ensure replacements don't also have any adverse effects, cancinogenic or otherwise.

Decisions on alternatives should be made after specialists have considered the full safety profile. C5-C8 alkane hydrocarbons are suspected of being neurotoxic, so that hazard should also be managed.
http://cdc.gov/niosh/pel88/142-82.html

Bruce Hamilton