3
EPAMethod Definitions
Many EPAmethods have been developed for the analysis ofVOCs. Virtually all VOCmeth-
ods employpurge and trap techniques to concentrate thevolatiles from the samplematrix. The
type of sample matrix being analyzed determines which method is used. We will discuss
drinking water methods (500 series), wastewater methods (600 series), hazardous waste
methods (8000 series), andContract Laboratory Program (CLP)methods. In addition, wewill
discuss state gasoline range organic (GRO)methods.
DrinkingWaterMethods (500 Series)
Proposed in 1973 by the EPA and passed byCongress a year later, the SafeDrinkingWater
Act (SDWA) establishes national standards for drinkingwater from surface and groundwater
sources. Thesemethods regulate the analysis of trace-level organic pollutants in drinking
water. Enforcement of the SDWA provides that states shall have the primary authority, while
theEPAwill oversee activities pertaining to the publicwater supply system. Thesemethods
have evolved over the years, which has resulted in a growing list of compounds of interest in
the subsequent revisions.
Method 502.2:
This capillary columnGCmethod is used tomonitor 60 regulated volatile
contaminants in drinkingwater. It employs a purge and trap concentrator, combinedwith a
photoionization detector (PID) and an electrolytic conductivity detector (ELCD) in series.
The PID detects aromatic and double-bond compounds, and the ELCD detects halogenated
compounds.
Method 504:
This capillary columnGCmethod is used tomonitor ethylene dibromide
(EDB) and dibromochloropropane (DBCP) in drinkingwater. It employsmicroextraction,
using hexane, and analysis using an electron capture detector (ECD).
Method 524.2:
This capillary columnGC/mass spectroscopy (GC/MS)method is used to
monitor the same 60 drinkingwater contaminants listed inMethod 502.2. It also employs
purge and trap concentration, but uses theMS to determine both aromatic and halogenated
compounds.
Method 524.2, Revision IV:
This capillary columnGC/MSmethod is used tomonitor the
60 compounds listed inMethods 524.2 and 502.2, plus 24 additional compounds.As of
Fall 2001, revisions were proposed to replace hydrochloric acid sample preservationwith
sodium thiosulfate. These revisions, however, were not promulgated at the time of this
printing.
WastewaterMethods (600 Series)
In 1977, President Carter signed theCleanWaterAct (CWA) allowing the EPA to study and,
if necessary, regulate 65 prioritywastewater pollutants.A cooperative effort between envi-
ronmental laboratories and the EPA resulted in the final version of what are now known as
the 600 seriesmethods. Thesemethods regulate the analysis of organic pollutants in industri-
al andmunicipal wastewater discharges. Theywerewritten for packedGC columns, but
most environmental laboratories now use capillary column technology.
Method 601:
ThisGCmethodwas developed tomonitor 29 halogenated volatile pollutants
inwastewater. It employs purge and trap concentration combinedwith anELCD.
Method 602:
ThisGCmethodwas developed tomonitor seven aromatic volatile pollutants
inwastewater. It employs purge and trap concentration combinedwith a PID.Many labora-
tories combineMethods 601 and 602 by using a PID and anELCD connected in series.
Method 624:
ThisGC/MSmethod uses purge and trap concentration tomonitor 35 halo-
genated and aromatic volatile pollutants inwastewater.
Method 1624:
This isotope dilutionGC/MSmethod uses purge and trap concentration to
monitor 58 volatile pollutants inwastewater. Stable, isotopically labeled analogs of the target
compounds are added to correct for analyte recoveries that might vary due tomatrix interfer-
ence in the analyzed samples.
