Your question was referred to me as I am the ATP program
In section 7.3 of Method 1664, it states that the n-hexane should
be "85% minimum purity, 99.0% minimum saturated C6 isomers, residue less
than 1 mg/L." The use of less pure n-hexane is not acceptable. If the
lab chooses to use n-hexane of lower purity, comparative studies would
have to be conducted and accepted via the ATP program. However, if the
lab uses purity greater than 85% for the n-hexane (i.e. 95% n-hexane),
comparative studies do not need to be conducted, since that falls within
the specifications of the method.
I hope this is helpful to you.
Marion Kelly, Robin
06/05/2006 04:29 Oshiro/DC/USEPA/US@EPA
Fw: EPA 1664 question
Can someone respond to this person?
Maria Gomez-Taylor, Deputy Director
Health and Ecological Criteria Division
Mail Code - 4304T
1200 Pennsylvania Avenue
N.W. Washington, D.C. 20460
----- Forwarded by Maria Gomez-Taylor/DC/USEPA/US on 06/05/2006 04:28 PM
06/05/2006 04:00 Gomez-Taylor/DC/USEPA/US@EPA
EPA 1664 question
As the 85% hexane is becoming more scarce, what are the available
options for the extraction solvent for EPA Method 1664 for NPDES work?
Is the use of the lesser grade solvents (e.g., 66%) acceptable if the QC
benchmarks in the method can be achieved?
Thank you for your time,
(See attached file: dana.satterwhite.vcf)