Chromatography Forum

Thanks for the information, I will be looking into getting some of those.

We are using a shaker with about a 1-2 inch throw, but at a fairly fast rate, maybe 1-1.5 cycles per second. It mixes the boston rounds enough that it takes a few minutes for the layers to separate.

The addition of the diethyl ether listed in the BLLE website makes the layers slower to separate also, and I am going to test without just to see how much advantage it gives in the extraction.

markf,

You can contact me at j.ball at mccoylabs . com

spaces added to avoid spam )

Looking at that website, they list 70ml and 250ml sizes for those tubes, do you use the 250ml or will the 70ml actually hold over 100ml?

we use the 250ml version

Thanks, I will be looking into those.

Just received confirmation email from my QC manager that the using method 3511 passed successful validation. YAY
I'm getting comparable (and with some analytes even better) results in all my sample matrices, and I'm very satisfied

Just received confirmation email from my QC manager that the using method 3511 passed successful validation. YAY
I'm getting comparable (and with some analytes even better) results in all my sample matrices, and I'm very satisfied

What extraction volume did you use?

I hope to get back to working on this soon. If they would just stop sending me so many new projects to look into I might finally get one finished

I use 30 mL of wastewater and 3 mL of DCM to extract it, then after shaking thouroughly on a orbital shaker for 20 minutes I gently centrifuge the vials (<1000rpm) to aid separation.
To remove the organic phase I use a large 5mL glass syringe, which can be used as a mini "separating funnel" in a pinch, if any amount of water phase managed to slip through.
I move the maximum amount of DCM I can with the syringe into a 4 mL vial, I add a bit of Na2SO4 to ensure it is completely dry, vortex, then after a few minutes I take a 1 mL aliquot into an injection vial, add the internal standard and inject.

Again, I understand completly that a 1t10 concentration does not satisfy every project goal, but if you don't need the extra sensitivity in a project, why work (so much) harder?

That sounds great. We are needing a little more sensitivity so I have been working with 100ml sample and extracting three times with solvent(six times when doing acid and base/neutral fractions). Then dry and process as usual.

We also just received a couple Large Volume Injection Ports that I am eager to try out and see how much more sensitive I can get.

Bottle Liquid-Liquid Extraction (BLLE) - "billie" is an automated, simple, economical and high quality alternative to the labor intensive and often emulsion laden separatory funnel technique. Papers, procedures, EPA approval for this new technique may be found at BLLE.org.

I received a reply back from EPA recently that confirmed they consider an extraction done in the bottle the same as if done in a separatory funnel as long as you follow the same steps. Therefore Method 3510C can be referenced when doing the extraction in the bottle shaking and removing the solvent with a pipette. Section 7.1 can be interpreted to allow for using a 100ml sample size as long as you have the sensitivity to meet the required limits of detection. This allowance has also been written into EPA 625.1 for waste water semi volatiles and the new EPA 608 for waste water Pesticides and PCBs.