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1,4 Dioxane - So Many Choices!

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1,4 Dioxane - So Many Choices!

Thursday, Sep 13, 2018

1,4 Dioxane has been designated by US EPA as an emerging contaminant that warrants monitoring due to potential adverse effects on the environment and/or human health.  1,4 Dioxane is a synthetic compound that has primarily been used as a stabilizer to prevent the breakdown of industrial solvents such as 1,1,1-Trichloroethane (TCA) during the manufacturing process.  It is highly soluble and stable in water, and does not readily adsorb onto soil particles, making the transfer from soil to groundwater or surface water relatively easy.  As such, 1,4-Dioxane is not only mobile in the environment, but also persistent. 

A federal maximum contaminant level (MCL) has not been established for 1,4-dioxane, nor is there a consensus method for the determination of 1,4-dioxane in water.  However, many states have implemented their own action levels based on EPA’s Health Advisory Level of 0.35 ug/L. 

Several characteristics of 1,4 Dioxane can make achieving low detection levels challenging.  Three methods are commonly used for determination of 1,4-dioxane. These are:  

  • Modified SW-846 8260 SIM 
  • U.S. EPA Method 522
  • Modified SW-846 8270 SIM with isotope dilution

To learn more about low level 1,4-dioxane, please visit our 1,4-dioxane web page or contact TestAmerica’s 1,4-dioxane expert, Eric Redman.

SW 846 Method 8260 (SIM) is a good, general purpose method for the determination of 1,4-Dioxane at reporting limits in the range of 1 to 2 ug/L (ppb). SIM refers to Selected Ion Monitoring, a technique used to improve sensitivity and allow lower detection limits.  The method generates good data quality, and high accuracy, but is not capable of achieving detection limits as low as the other methods. Within TestAmerica, isotope dilution quantitation is often used in conjunction with method 8260 SIM to improve data quality.

EPA Method 522 was designed exclusively for drinking water samples.  The method utilizes solid phase extraction followed by GC/MS analysis in SIM mode.  This analysis yields low detection limits and good recoveries, but applicability may be limited for complex sample matrices

Modified SW 846 Method 8270 (SIM with isotope dilution) is the most reliable method for achieving low detection limits in a variety of matrices. Isotope dilution reduces the impact of low recovery bias that occurs when using other quantitation approaches.    Isotope Dilution employs the spiking of a known quantity of an isotopically labeled internal standard in to the sample.  Recoveries of the labeled standard can be measured, allowing for the correction of any low bias in the recovery of 1,4-dioxane.



Detection Limits


Data Quality

SW846 8260 SIM


1 to 2 ug/L



EPA 522


0.2 ug/L



SW846 8270 SIM ID


0.2 – 0.4 ug/L




9/13/2018   1,4 Dioxane - So Many Choices!

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