I have run a Demonstration of Capability study using 100ml boston round bottles as the separatory funnel and shaking on a horizontal shaker table. Using the solvents listed in the Bottle Liquid Liquid Extraction procedure
http://blle.org/method-approval-process/ which has been approved for several methods so far. The shaker table is a modification that I did to speed up the process. Shaking for 10 minutes each time then 10 minutes in a centrafuge(definitely helps separate the layers and for actual samples almost necessary for emulsion breaking) I use a pipette to remove the organic layer. Three extractions in the acid, then add salt and three extractions in the base, just as the blle procedure. I just managed to average almost 70% recoveries on EPA625 analytes from DI water and 60% on actual waste water samples. It is actually better recoveries than we were getting on continuous liquid liquid extraction. I then use 5-10ul injections to improve sensitivity.
I have sent an email to the MICE site to ask if the sample bottle can be considered equivalent to a separatory funnel so we can claim EPA Method 3510C as the extraction method, or if we have to claim EPA Method 3511 microscale extraction method with modification to larger vial size. If a separatory funnel can be defined as not having to include a stopcock at the bottom then either method should be applicable.
- 100ml sample in a glass centrifuge-tube with GL45 cap.
BMU_VMW, where did you find these centrifuge tubes? Those I think would be even better than doing the extraction in the bottle, just for purposes of centrifuging since you have to limit the centrifuge speed on the bottles to prevent breaking them.