552

[Bigbear]

Anyone out there using an internal standard that can be added to the MTBE extraction solvent? I really don't like the post extraction spiking of 1,2,3-TCP.

[twranger]

EPA 552.3 uses the ISTD in the extraction solvent, we have found it works quite well. I have less extraction variablity and better recovery, probably due to using more acid at derivatization and no CuSO4. I also use a different surrogate, the method surrogate has given me wildly different results between batches/technicians.

[sw340496]

Have any of you had any problems with interferences in the chromatograms when doing 552.3? I'm seeing a large number of interference peaks all over my chromatogram especially near the surrogate on my primary column I have very consistent recoveries on one column whereas on the column the results seem to be all over the place.