5.1 This is a performance based method, and modifications are allowed to improve performance.

5.1.1 Due to the rapid development of newer instrumentation and column chemistries changes to the analysis described in this standard are allowed as long as better or equivalent performance data result. Any modifications shall be documented and performance data generated. The user of the data generated by this Standard shall be made aware of these changes and given the performance data demonstrating better or equivalent performance.

5.2 TDG is a Schedule 2 compound under the Chemical Weapons Convention (CWC).6 Schedule 2 chemicals include those that are precursors to chemical weapons, chemical weapons agents or have a number of other non-military commercial uses. Schedule 2 chemicals can also be found in applications unrelated to chemical weapons. These chemicals are used as ingredients to produce insecticides, herbicides, lubricants, and some pharmaceutical products. TDG is a mustard gas precursor and a degradant as well as an ingredient in water-based inks, ballpoint pen inks, dyes, and some pesticides.

5.3 This method has been investigated for use on surface wipes. TDG is also a human metabolite resulting from sulfur mustard exposure but this method has not been investigated for such determinations.

1.1 This procedure details the determination of thiodiglycol (TDG), also known as 2,2’-thiobis-ethanol, on wipes with 3,3’-thiodipropanol (TDP) as the surrogate. This method is based upon solvent extraction of wipes by either sonication or a pressurized fluid extraction (PFE) technique as an alternative option. The extract is filtered, concentrated and analyzed by liquid chromatography/tandem mass spectrometry (LC/MS/MS). TDG is qualitatively and quantitatively determined.

1.2 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3 The Method Detection Limit (MDL)2 and Reporting Range3 for TDG are listed in Table 1.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.