Chromatography Forum

What can you change, and what is cast in stone by the official methods you choose to follow?

There is no point us suggesting things that will work but that you are not allowed to change.

Bear in mind that not everyone knows the details of the official methods.

Peter

We use EPA methods, for GRO: Analysis method 8015C:
https://www.epa.gov/sites/production/fi ... -8015c.pdf

For prep we use method 5021A:
https://www.epa.gov/sites/production/fi ... /5021a.pdf

Those methods are, of course, free to browse and use.

Page 4 states:
Gasoline range organics may be introduced into the GC/FID by purge-and-trap (Methods 5030 and 5035), automated headspace (Method 5021), vacuum distillation (Method 5032), or other appropriate technique.

*shrug* So, I guess, not direct injection, not that it would likely to help me by much.

Method 5021 clearly states to use Methanol as the basis to all standards and extracts.

8015 does allow for direct injection so you could probably get away with doing a methanol extraction of the sample under a modification of the DRO extraction procedure to use methanol.

When in doubt about what is acceptable for any SW846 methods you can contact MICE http://www.ehso.com/cssepa/SW846testmethods.htm

Near the bottom of the page you will see phone numbers and email for the MICE service, I have used it many times for guidance on what is allowed and not allowed and many times they give the OK for things that are not spelled out in the methods. I have even gotten guidance from them on things like using MRM and SIM with 8260 and 8270.

"or other appropriate technique."

Means that you can do what you like as long as it works.

Don't take it the wrong way if I tell you that I have better things to do than read all the way through those methods when it is not me who has a problem with them.

Peter

No offense taken, thanks for taking the time to think about it, that's what I've asked.

What can you change, and what is cast in stone by the official methods you choose to follow?

There is no point us suggesting things that will work but that you are not allowed to change.

Bear in mind that not everyone knows the details of the official methods.

Peter

We use EPA methods, for GRO: Analysis method 8015C:
https://www.epa.gov/sites/production/fi ... -8015c.pdf

For prep we use method 5021A:
https://www.epa.gov/sites/production/fi ... /5021a.pdf

Those methods are, of course, free to browse and use.

Page 4 states:
Gasoline range organics may be introduced into the GC/FID by purge-and-trap (Methods 5030 and 5035), automated headspace (Method 5021), vacuum distillation (Method 5032), or other appropriate technique.

*shrug* So, I guess, not direct injection, not that it would likely to help me by much.

Method 5021 clearly states to use Methanol as the basis to all standards and extracts.

8015 does allow for direct injection so you could probably get away with doing a methanol extraction of the sample under a modification of the DRO extraction procedure to use methanol.

When in doubt about what is acceptable for any SW846 methods you can contact MICE http://www.ehso.com/cssepa/SW846testmethods.htm

Near the bottom of the page you will see phone numbers and email for the MICE service, I have used it many times for guidance on what is allowed and not allowed and many times they give the OK for things that are not spelled out in the methods. I have even gotten guidance from them on things like using MRM and SIM with 8260 and 8270.

I'll try contacting MICE, I have not known that they had this type of "helpline" before, thanks!