Page 1 of 1

Methylene Chloride

Posted: Thu Apr 20, 2023 5:53 pm
by MichaelVW
https://www.epa.gov/assessing-and-manag ... e-chloride

EPA has proposed a partial ban on DCM. Maybe we'll see an increase in price, availability, and necessary safety documentation.

Has anyone done 8270 with a different solvent for your cal standards?

Re: Methylene Chloride

Posted: Fri Apr 21, 2023 8:28 pm
by James_Ball
I have not done 8270, but we do use Ethyl Acetate for 525 and it works very well.

I hope this doesn't turn out to be a replay of the Freon fiasco from 20 years ago when they banned it and still required it for the Oil and Grease test, and would not allow a substitute solvent until over a year later when they finally approved a new method. I remember paying something like $800 for a container before it was finished.

Re: Methylene Chloride

Posted: Mon Jul 31, 2023 2:28 am
by LALman
https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/risk-management-methylene-chloride

EPA has proposed a partial ban on DCM. Maybe we'll see an increase in price, availability, and necessary safety documentation.

Has anyone done 8270 with a different solvent for your cal standards?
Its been a long time since I used to extract PCB's with MeCl. But we also used the alternative solvent combo: Hexane:Acetone 1:1. It was part of the method back in the 1990's. That is for extraction. Then you can blow it down into Ethyl acetate as suggested above, although we used MeCl. But I have only tried Ethyl acetate with DRO. Oh and a hint at least for PCB's might not be appropriate for full 8270. I would dissolve 1mL of mineral oil in 100-500mL of hexane and add 1mL of that to every sample. If the blow down went too far; it made a great keeper for all the PCB's.

Re: Methylene Chloride

Posted: Fri Dec 29, 2023 3:22 pm
by ajc92
Hi! First-time poster, long-time reader.
Hoping to revive this thread, as I would be interested to hear about an alternative to DCM for 8270 as well - also with the intention of moving the prep procedure to 3535 - I've been scouring for papers about alternative solvents for the 8270 list but not coming up with much - As James_Ball mentioned since 525 uses EtOAc primarily it may be a starting point? I have data for 8270 by 3535 using DCM, but I would like to get ahead of the drought if I can. Wondering if anyone's gained more insight.
Thanks!

Re: Methylene Chloride

Posted: Fri Aug 23, 2024 8:51 pm
by LALman
I'm pretty sure 1:1 Hexane:Acetone is mentioned in the 8270 method as an alternative extraction solvent. c.f. Table 8 in 8270D. Soxlet extraction (method 3541) with Hexane-Acetone.

Re: Methylene Chloride

Posted: Sun Aug 25, 2024 2:36 pm
by Consumer Products Guy
I hope this doesn't turn out to be a replay of the Freon fiasco from 20 years ago when they banned it and still required it for the Oil and Grease test, and would not allow a substitute solvent until over a year later when they finally approved a new method. I remember paying something like $800 for a container before it was finished.
Or the official cholesterol assay that used benzene but benzene was no longer allowed to be sold/used in labs.