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Posted: Wed Jan 21, 2009 4:55 pm
by Bigbear
I too was chasing the bis (2- ethyl hexyl)phthalate problem , and found it was coming from the "green" septa. I changed to Aglent BTO septa and swapped (2- ethyl hexyl)phthalate for di-n- Butylphthalate!
Re: Anyone run EPA 525.2? IS recovery?
Posted: Fri Dec 10, 2010 2:04 pm
by LadyChemist
I've been using p-terphenyl and it does help your recoveries. IS/SS recoveries are VERY matrix dependent and the p-terphenyl seems to compensate.
I've been running 525.2 for about 10 years. This method certainly is different from most other EPA methods as far as adding IS and SS before extraction, etc.
Re: Anyone run EPA 525.2? IS recovery?
Posted: Mon Dec 13, 2010 7:08 pm
by gpronger
"LadyChemist";
First, you must have someone else handle you're electronics repair (never been shocked).
More seriously, do you have any thoughts regarding optimizing the recovery for the spiked internal standards? Intermittent erratic recoveries occur for us, and so far we have been unable to really define what was the cause or how to avoid the problem.
Greg
Re: Anyone run EPA 525.2? IS recovery?
Posted: Wed May 18, 2011 10:18 am
by jarodw
have been running 525.2 for some time....IS recovery is based on an unextracted standard as compared to the extracted SPE samples
in other words ratio of IS to SS in unextracted vs extracted sample
IS recovery are usually very good ~100%. lower recovery seen when sample not dechlorinated