Chromatography Forum

Hello all,

Is anyone running acetone by SW-846 Method 8260C?

If so, how is the recommended minimum RRF of 0.1 (Table 4) met using the primary characteristic ion of 58 (Table 5) with Fluorobenzene as the referenced internal standard (mass 96 from Table 5)?

I typically see an RRF of 0.02 to 0.04 under these conditions.

Thank you for your time.

I think it is treated as "recommended, not required". I know our joint just shrugs it off (.01 may be the threshold we get concerned at). The min RRF stuff makes sense for many analytes, but the method would need to use a deuterated ketone to work out for acetone. No one wants to go there...

I think we are running under 8260B (Kentucky doesn't yet recognize 8260C ). I have always used m/z 43 to quant Acetone because m/z 58 is only about 35% abundance and is listed as the alternate mass. But even using that and running Pentafluorobenzene with m/z 99 I barely get 0.15 RRF. Fluorobenzene has a better response and combined with using mass 58 I don't see any way to get 0.1RRF for Acetone. With a heated purge and some creative tuning maybe, but still doubtful.

I had to have our QC officer write some exceptions into our SOP because he originally had even 1,4-Dioxane requiring 0.1RRF, if you can get 0.002RRF on it you are very lucky.

Response factors in the table are only recomendations in 8260. The language for 8260C was clarified to make that more apparent. It still wasn't consistent throughout so it will be revised again in the next update. Some of the target compounds in section 1.1 have very low responses compared to the listed internal standards and would need to be at higher concentrations to provide usable signal to noise.

James, Kentucky still at 8260B? It's nice to know that EPA isn't the slowest government agency around. We were working on 8260C ten years ago!

Thank you all for the replies. You all confirmed my suspicions. Convincing external auditors that there is a difference between "recommended" and "written in blood on a stone" will be the next step.

Thanks again.

Thank you all for the replies. You all confirmed my suspicions. Convincing external auditors that there is a difference between "recommended" and "written in blood on a stone" will be the next step.

Thanks again.

Good luck! We have to do it constantly with each new auditor that comes by

Response factors in the table are only recomendations in 8260. The language for 8260C was clarified to make that more apparent. It still wasn't consistent throughout so it will be revised again in the next update. Some of the target compounds in section 1.1 have very low responses compared to the listed internal standards and would need to be at higher concentrations to provide usable signal to noise.

James, Kentucky still at 8260B? It's nice to know that EPA isn't the slowest government agency around. We were working on 8260C ten years ago!

They did on our last contract, I need to check what the new one says. I do know that they are trying to update as much as possible as they begin to implement the new waste water certification requirements here. I do still receive samples from the state where the soils are still sampled in 4oz soil jars instead of using the Encore samplers or sampled directly into the 40ml vials which is the newest method for purge and trap sampling(which is also over 10 years old).

The published methods never die, given various agencies, states, auditors, etc. I find it best to keep my head down and let someone else handle them now .