About epa 525.2 method!
Posted: Thu Apr 28, 2011 8:14 am
Hello to everybody...
In method epa 525.2 for semivolatiles analysis, every compound has an IS reference (acenaphtene-d10, crysene-d12 and phenenathrene-d10) to calculate de response with it. I thinked theoretically that the use of an especific internal standard is mainly based in similar retention time between the IS and the target anlalyte. But, there are some compounds, ex: the high boiling PAHs (benzo(a)pyrene, benzo(b)fluoranthene, etc.) that are related to other IS instead the IS whit most simlar retention time ( PAHs are relate to Phenanthrene-d10 in the method, phenanthrene-d10 has a retention time about 10-11 min, and not to crysene with 18-21 min very nearly to the HAPs mentioned.
Does anybody some knowledge about it, which is the reason??
Thaks in advance
RicK
In method epa 525.2 for semivolatiles analysis, every compound has an IS reference (acenaphtene-d10, crysene-d12 and phenenathrene-d10) to calculate de response with it. I thinked theoretically that the use of an especific internal standard is mainly based in similar retention time between the IS and the target anlalyte. But, there are some compounds, ex: the high boiling PAHs (benzo(a)pyrene, benzo(b)fluoranthene, etc.) that are related to other IS instead the IS whit most simlar retention time ( PAHs are relate to Phenanthrene-d10 in the method, phenanthrene-d10 has a retention time about 10-11 min, and not to crysene with 18-21 min very nearly to the HAPs mentioned.
Does anybody some knowledge about it, which is the reason??
Thaks in advance
RicK