NEMI Method Summary

Method Summary Information

Method Number: 601 Media: WATER
Revision: 40 CFR Part 136, Appendix A (Current Edition)
Method Source: U.S. EPA Engineering and Analysis Division
Subcategory: ORGANIC Analytes in this method
Official Name: Purgeable Halocarbons
Descriptive Name Purgeable Halocarbons via GC with Electrolytic conductivity (ELCD) or microcoulometric detector
Source Info: 4303 USEPA Headquarters
Ariel Rios Building
1200 Pennsylvania Avenue, N. W.
Washington, DC 20460
Citation: EPA Method Guidance CD-ROM (includes MCAWW Methods, and most current EPA Methods)
158728 Byte file
Brief Method
Summary:
 A sample is purged with an inert gas transforming the halocarbons to the vapor phase which is collected on an absorbent trap at ambient temperature. After the sample is purged, the trap is then heated, and backflushed with the inert gas onto an chromatographic column. The gas chromatograph is temperature programmed to separate the halocarbons which are then detected by a halide-specific detector. Method 624 can be used for GC/MS confirmation of compound match or interference.
Scope And
Application:
 This method determines target compounds potentially found in municipal and industrial discharges.
Applicable
Conc Range:
 MDL to 1000xMDL (ug/L).
Interferences: (A) Impurities in gas and plumbing: Impurities in the inert gas and organic plumbing system of the purge and trap concentrator tend to be the main cause of interference in the analytical system. The use of non-Teflon tubing and fittings should be avoided.
(B) Contamination during collection: Samples can become contaminated by diffusion of volatile organic compounds across the septum seal during collection and storage. Use Field Blanks to verify possible contamination.
Carryover: Contamination by carry-over in the analytical system can occur, especially in sample that are extremely concentrated. Frequent bakeout and cleaning of the purging system can help prevent carry-over
QC Requirements: Initial demonstration of laboratory capability and the periodic analysis of laboratory reagent blanks, fortified blanks, and other laboratory solutions as a continuing check on performance.
Sample Handling: Sample should be placed in a 25 mL or larger glass vial; screw cap with a hole in the center for a Teflon-faced silicone septum. The sample should not have a headspace and should be kept refrigerated until analysis. If the sample is believed to have free or combined chlorine, add 10mg/40mL of sodium thiosulfate upon collection and shake vigorously for one minute.
Max Holding Time:
 14 days
Sample Prep Met None.
Relative Cost: $201 to $400
5227
Page 1