EPA Method 548.1

ALS - Columbia offers EPA Method 548.1 testing at these laboratories:

Kelso Kelso, Washington Laboratory

Method information displayed is provided for informational purposes only. No warranty (express or implied) is made as to the website accuracy, completeness, or applicability (such as the age of a method and whether or not it applies to your project). Please contact us for assistance. Analytical testing dots

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EPA Method 548.1:
Determination of Endothall in Drinking Water by Ion Exchange Extraction, c Acidic Methanol Methylation and Gas Chromatography/Mass Spectrometry -Revision 1.0.

A 100-mL sample is passed through a liquid/solid extraction (LSE) cartridge containing an intermediate strength, primarily tertiary amine anion exchanger mounted on a vacuum manifold and conditioned with appropriate solvents. Extracted endothall is eluted from the LSE cartridge with 8-mL of acidic methanol. After adding a small volume of methylene chloride as a co-solvent, the dimethyl ester of endothall is formed within 30 minutes with modest heating. After addition of salted reagent water, the ester is partitioned into 8-10 mL of methylene chloride. The extract volume is reduced with a nitrogen purge. The concentration of endothall in the extract is measured using a megabore capillary column gas chromatography (GC) system equipped with a mass spectrometer detector (MS) or a flame ionization detector (FID). A FID may be utilized for the determination of endothall, but must be supported by an additional analysis using a confirmatory gas chromatographic column.

This method determines endothall in drinking water sources and finished drinking water.

Methods for the Determination of Organic Compounds in Drinking Water - Supplement II (EPA/600/R-92-129)

(A) Glassware contamination: Thoroughly clean glassware, including baking or solvent rinse.(B) Reagent contamination: Use high purity reagents.(C) Ion interferences: Ca+2 and Mg+2 and sulfate lower recovery by interfering with the ion exchange process.(D) Extracted interferences: Interference from extracted non-target compounds, with retention times similar to target compounds, can be reduced by cleaning the extract.

QC Requirements:
Initial demonstration of laboratory capability, followed by analysis of laboratory reagent blanks (LRBs), laboratory fortified matrix samples, laboratory fortified blanks (LFBs), and QC check standards. A MDL also must be determined.

Maximum Holding Time:
7 days; 14 days for extracts.



Not specified in method. Range differs depending on matrix and instrumentation.


The MDL was determined using the standard deviation of 7 replicate analyses of an analyte-fortified reagent water sample (2 ug/L of endothall) multiplied by the t-value for 6 degrees of freedom at the 99% confidence level. Detailed instructions for how MDLs are determined are found at 40 CFR part 136, Appendix B.

Revision Number:
Revision 1.0, August 1992

Test Description:
Endothall by LSE & G

Report Number:

Instrument used for this test:

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At least 1 analytes can be tested by ALS - Columbia using EPA Method 548.1. Please contact us for all available analytes which can be tested by EPA Method 548.1.

AnalyteCAS Number

Examples:  8260

Examples:  Dioxin
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