ColumnsRecommended inMethod 8095
•
EPA8095 lists theDB
®
-1 (100%dimethylpolysiloxane) and theHP
®
-5 (5%
diphenyl 95%dimethylpolysiloxane) as possible primarycolumns.
•
TheDB
®
-1 completelyco-elutes RDXandPETN.
•
TheHP
®
-5 resolvesRDXandPETNbut usuallyco-elutes 4-amino-2,6-
dinitrotoluene and3,5-dinitroaniline.
•
TheRtx
®
-TNT ismuch better than theDB-1 sinceRDX/PETN is a critical
separation.
•
EPA8095 list theRtx
®
-200 (trifluoropropylmethyl polysiloxane) and the
Rtx
®
-225 ( 50%cyanopropyl methyl 50%phenylmethyl polysiloxane) as the
possible confirmational columns.
•
TheRtx
®
-200 is significantlymore retentive than anyof the primary columns.
HMX is usuallynot detected.
RDXand 2-amino-4,6-dinitrotoluene co-elute.
Nitroglycerin and 2,6-dinitrotoluene co-elute.
•
TheRtx
®
-225 has poor thermal stability.
The column is only stable to260
°
C.
This column is also too retentive.
ECDbleed levels are also an issuewith
cyano containingpolymers.
•
TheRtx
®
-TNT2 is better than anyof the confirmational columns since all
compounds canbe detectedwith the theRtx
®
-TNT in a simultaneous dual-
column run.
