Description_x000D_ General description_x000D_ This proficiency testing sample is produced in accordance with ISO/IEC 17043:2010. All information regarding the use of this material can be found in the reporting packet supplied for each sample._x000D_ Preparation Note_x000D_ The PT sample is packaged as a 20 mL concentrate._x000D_ The sample matrix is water._x000D_ This PT is suitable for EPA Method 7._x000D_ Sample preparation_x000D_ To prepare solution, partially fill a 1000 mL volumetric flask with reagent-grade water (near 20 °C)._x000D_ Open ampoule PEA1904-20ML (be careful to avoid cuts on glass) and transfer 10.0 mL of the concentrate into the volumetric flask._x000D_ Fill to volume (1000 mL) with reagent-grade water and mix well._x000D_ The sample is now ready for immediate analysis_x000D_ Other Notes_x000D_ Proficiency testing samples are presented as single blind. No values for the samples are released until the testing period concludes. Values of analytes vary lot to lot._x000D_ Proficiency Testing Schedule (2020-2021)_x000D_ Air_x000D_ AIR20-2 April 8 - May 22, 2020_x000D_ AIR20-4 October 7 - November 20, 2020_x000D_ AIR21-2 April 7 - May 21, 2021_x000D_ AIR21-4 October 6 - November 19, 2021_x000D_ Quick-Turn Study Not Available for this Product