EPA Method 531.1

ALS - Columbia offers EPA Method 531.1 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 531.1:
Measurement of N-Methylcarbamoyloximes and N-Methylcarbamates in Water by Direct Aqueous Injection HPLC with Post Column Derivatization -Revision 3.1.

An aliquot of a filtered water sample is injected into a reverse phase high performance liquid chromatography (HPLC) column. Separation of the analytes is achieved using gradient elution chromatography. After elution from the HPLC column, the analytes are hydrolyzed with sodium hydroxide. The methyl amine formed during hydrolysis is reacted with o-phthalaldehyde (OPA) and 2-mercaptoethanol to form a highly fluorescent derivative (post-column derivitization). The concentrations of analytes eluted from the HPLC column are measured by detecting the fluorescence of derivatives with a fluoresence detector.

This method determines certain N-methylcarbamoyloximes and N-methylcarbamates (analytes) in ground water and finished drinking water.

Methods for the Determination of Organic Compounds in Drinking Water - Supplement III (EPA/600/R-95-131)

(A) Glassware contamination: Thoroughly clean glassware, including baking or solvent rinse.(B) Reagent contamination: Use high purity reagents.(C) Contamination from sample carryover: Rinsing apparatus with water and purging equipment between analyses can minimize contamination.(D) Matrix interferences: Matrix interferences may be mitigated by using a different detector that operates on different chemical/physical principles than the original detector, or by using different chromatography columns. Alternative chromatography columns are described in the method.

QC Requirements:
Initial demonstration of laboratory capability, monitoring internal standard peak area or height in each sample and blank (when internal standard calibration procedures are being employed), followed by analysis of laboratory reagent blanks (LRBs), laboratory fortified samples, laboratory fortified blanks (LFBs), and QC samples. A MDL for each analyte must also be determined.

Maximum Holding Time:
28 days.



Not Provided.

Precision and accuracy values were determined using single laboratory data from seven to eight replicate analyses of reagent water fortified with the analytes of interest.

MDLs were determined using the standard deviation of 7 or replicate analyses of an analyte-fortified reagent water 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 and Section 9.2.4 of the method.

Revision Number:
Revision 3.1, 1995

Test Description:

Report Number:

Instrument used for this test:

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At least 11 analytes can be tested by ALS - Columbia using EPA Method 531.1. Please contact us for all available analytes which can be tested by EPA Method 531.1.

AnalyteCAS Number
4-Bromo-3,5-dimethylphenyl N-Methylcarbamate672-99-1
Aldicarb Sulfone1646-88-4
Aldicarb Sulfoxide1646-87-3

Examples:  8260

Examples:  Dioxin
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