Ethylene Oxide analysis

[dslocum]

Does anybody have experience running ethylene oxide by GC? I would be interested in finding out where you purchased ethylene oxide from. The USP directs you to use liquid ethylene oxide. Where do you find that?

[rb6banjo]

In the US we can get it at Sigma-Aldrich:

http://www.sigmaaldrich.com/catalog/sea ... partialmax

Looks like the sell the pure stuff you can get it dissolved in various solvents. EO is a tough one because it has such a low boiling point. Transportation is difficult.

Good luck.

[dslocum]

Yeah, Sigma-Aldrich is the only place I have been able to find straight EO. I think they are selling it as a gas though. I wonder if anyone sells liquid EO. You can cool the gas to collect liquid (the EP suggests this), which seems to be a hassle. The method in the NF just simply presupposes that you have liquid EO, which is why I am wondering if you can purchase it from somewhere.

[Meerkat]

I just ran a gc quant assay on eth oxide and dioxane from a sample matrix of pertrolatum using hs/gc. As a ref std I used Fisher reagent grade eth oxide and labelled it as a "secondary std" enclosing a cert of analysis with it. Everything worked out fine, as I'm sure it will for you also.

[Johnny Rod]

Why does it say liquid? What do you do with it?

[Peter Apps]

Ethylene oxide comes as a liquid in pressurized cylinders (just like liquid CO2 and liquid propane or butane). It boils at 10C, so you either have to turn your air conditioning down really low, or connect the cylinder to plumbing that will allow you to handle it as a gas.

Peter

[dslocum]

I definitely appreciate the replies. Does anyone have a supplier/part number for Ethylene Oxide that you have used? The only one I have found is the $622 tank that Sigma Aldrich offers. I would be interested in knowing who else supplies EO.

[BHolmes]

At my last job I routinely analyzed polymer samples for residual EO using GC-FID, no headspace. EO analytical standard in dichloromethane was obtained from Sigma-Aldrich and was shipped cold, it also had to be stored at <10degC. more info here: http://www.sigmaaldrich.com/catalog/pro ... &region=US. When making additional EO standards in dichloromethane, I had to wear nitrile gloves, silver shield gloves, lab coat, and silver shield apron w/full sleeves to protect against EO. I also worked in a Fume Hood that was connected to an EO scrubber to prevent release to atmosphere - my last employer took no chances on contaminating the environment - something I truly miss at times....
This method of standard preparation was randomly tested for safety using OSHA recommended method and no significant amount of EO was ever detected in the workplace. full info on OSHA test can be found here: https://www.osha.gov/pls/oshaweb/owadis ... p_id=10074

I highly recommend purchasing EO already in solution and then making dilutions from there. Much safer than working with pure EO in gas form.

[Johnny Rod]

It's a good point, EO is very nasty stuff

[SmitaKamal]

Were you able to get Eo standards. Let me know if you are still looking for them.I have the part number... But at work... i get my vials of 1ml for $32.
Is your method working now?

[MestizoJoe]

I use EO from a gas supplier. I make my own standards which are EO in DI water. This takes me about 15 min and is not a hassle. It also seems much more accurate than what is suggested in ISO 10993-7 (2008), which is used for residual testing of medical devices.

Our lab got training on how to handle EO gas properly, but it is not difficult. Everything is done in the hood and ppe is worn.

We had standards from Alrich in ampules but I didn't like that since the vapor pressure of EO in water (our extract solution) is different than in THF or some other solvent. Standards in water are not available since EO is too reactive.

[dslocum]

SmitaKamal...yes, I was able to get a quote from SPEX CertiPrep for the EO in PEG200, which is the stock solution for the USP method <228>. However, it turns out we have an old tank of EO here in the lab which I have used to begin my analysis, and yes, I have the method up and running now. What is the part number you use? $32 is about 1/3 of the quote I received.

MestizoJoe, thanks for the comments! I have just been using EO in water, too, because I do not have any PEG200 yet. We have a tank of EO here and you are right...it is not too much of a hassle to use it. Ballbuster Union, huh? How do you join that?