environmental
Applications
note
RestekCorporation • (800) 356-1688 • (814)353-1300 •
#59539
environmental
GCAnalysis of USEPAMethod 504.1OrganochlorinePesticides
Using theRtx
®
-CLPesticides andRtx
®
-CLPesticides2Columns
UnitedStatesEnvironmental ProtectionAgency (USEPA)
Method504.1 is a common test performedby environmental
laboratories for the analysis of 1,2-dibromoethane (EDB), 1,2-
dibromo-3-chloropropane (DBCP), and1,2,3-trichloropropane
(TCP) indrinkingwater. Thismethoduses a salting-out
microextractionanddual-columngas chromatographywith
electron capturedetection (GC/ECD). Because theworkloadof
Method504.1usuallydoes notwarrant the dedicationof an
instrument,many laboratories use the same instruments for the
analysis of chlorinatedpesticides andherbicides.Therefore,
when selecting a set of capillary columns for this analysis, it is
important that theyworkwell for a number of differentmethods.
Restekhas designed theRtx
®
-CLPesticides and theRtx
®
-
CLPesticides2 columns specifically for the analysis of orga-
nochlorinepesticides (EPAMethods 608 and8081), and they
alsoprovide excellent separation for the compounds listed in
Method504.1. In addition to the analytes listed inMethod504.1,
these stationaryphases alsoworkwell for the analysis of
herbicides andpolychlorobiphenyls (PCBs) because they are
highly selective for compounds that contain electronegative
substituents.
Figure 1
shows the analysis of theMethod504.1 target com-
pounds on theRtx
®
-CLPesticides and theRtx
®
-CLPesticides2
columns, connected inparallel using aglass ‘Y’Press-Tight
®
connector. This configuration is important to ensure that both the
primaryandconfirmationcolumnanalyses areperformed
simultaneouslyunder the same conditions, using the same
injectionport.
Method504.1 requires that EDB,DBCP, andTCPbe fully
resolved from the common interference compounds (i.e.,
chloroform,bromodichloromethane, chlorodibromomethane,
1
2
3
4
5
7
Figure1
Rtx
®
-CLPesticides andRtx
®
-CLPesticides2 columns fully resolveMethod504.1organochlorine pesticides in10minutes.
1. chloroform
2. bromodichloromethane
3. chlorodibromomethane
4. 1,2-dibromoethane (EDB)
6
30m, 0.32mm ID, 0.50µmRtx
®
-CLPesticides (cat.# 11139) and 30m, 0.32mm ID, 0.25µmRtx
®
-CLPesticides2 (cat.# 11324),
0.32mm ID guard column (cat.# 10044), universal angled ‘Y’ Press-Tight
®
connector (cat.# 20403). Direct injection using a Uniliner
®
sleeve (cat.#20335).
On-column concentration:
10pg each compound.
Oven temp.:
35°C (hold 2min.) to 300°C@ 12°C/min.;
Inj./det. temp.:
200°C/300°C;
Carrier gas:
helium, 12psi constant pressure.
1
2
3
4
5
7
6
Rtx
®
-CLPesticides Column
Rtx
®
-CLPesticides2 Column
5. 1,1,1,2-tetrachloroethane
6. bromoform
7. 1,2,3-trichloropropane
8. 1,2-dibromo-3-chloropropane (DBCP)
8
8
min. 3
4
5
6
7
8
9
10
min. 3
4
5
6
7
8
9
10
